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openwrtv4/target/linux/brcm2708/patches-4.4/0040-Add-SMI-driver.patch

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brcm2708: update linux 4.4 patches to latest version As usual these patches were extracted and rebased from the raspberry pi repo: https://github.com/raspberrypi/linux/tree/rpi-4.4.y Also adds support for Raspberry Pi Compute Module 3 (untested). Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2016-09-10 12:54:26 +00:00
From d85d7801b25872d08bd848c40da8fce973db5e46 Mon Sep 17 00:00:00 2001
brcm2708: add linux 4.4 support - random-bcm2708 and spi-bcm2708 have been removed. - sound-soc-bcm2708-i2s has been upstreamed as sound-soc-bcm2835-i2s. Let's keep linux 4.1 for a while, since linux 4.4 appears to have some issues with multicast traffic on RPi ethernet: https://gist.github.com/Noltari/5b1cfdecce5ed4bc08fd Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 48266
2016-01-17 10:42:23 +00:00
From: Luke Wren <wren6991@gmail.com>
Date: Sat, 5 Sep 2015 01:14:45 +0100
brcm2708: update linux 4.4 patches to latest version As usual these patches were extracted and rebased from the raspberry pi repo: https://github.com/raspberrypi/linux/tree/rpi-4.4.y Also adds support for Raspberry Pi Compute Module 3 (untested). Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2016-09-10 12:54:26 +00:00
Subject: [PATCH] Add SMI driver
brcm2708: add linux 4.4 support - random-bcm2708 and spi-bcm2708 have been removed. - sound-soc-bcm2708-i2s has been upstreamed as sound-soc-bcm2835-i2s. Let's keep linux 4.1 for a while, since linux 4.4 appears to have some issues with multicast traffic on RPi ethernet: https://gist.github.com/Noltari/5b1cfdecce5ed4bc08fd Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 48266
2016-01-17 10:42:23 +00:00
Signed-off-by: Luke Wren <wren6991@gmail.com>
---
.../bindings/misc/brcm,bcm2835-smi-dev.txt | 17 +
.../devicetree/bindings/misc/brcm,bcm2835-smi.txt | 48 +
drivers/char/broadcom/Kconfig | 8 +
drivers/char/broadcom/Makefile | 2 +-
drivers/char/broadcom/bcm2835_smi_dev.c | 402 +++++++++
drivers/misc/Kconfig | 8 +
drivers/misc/Makefile | 1 +
drivers/misc/bcm2835_smi.c | 985 +++++++++++++++++++++
include/linux/broadcom/bcm2835_smi.h | 391 ++++++++
9 files changed, 1861 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/misc/brcm,bcm2835-smi-dev.txt
create mode 100644 Documentation/devicetree/bindings/misc/brcm,bcm2835-smi.txt
create mode 100644 drivers/char/broadcom/bcm2835_smi_dev.c
create mode 100644 drivers/misc/bcm2835_smi.c
create mode 100644 include/linux/broadcom/bcm2835_smi.h
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/brcm,bcm2835-smi-dev.txt
@@ -0,0 +1,17 @@
+* Broadcom BCM2835 SMI character device driver.
+
+SMI or secondary memory interface is a peripheral specific to certain Broadcom
+SOCs, and is helpful for talking to things like parallel-interface displays
+and NAND flashes (in fact, most things with a parallel register interface).
+
+This driver adds a character device which provides a user-space interface to
+an instance of the SMI driver.
+
+Required properties:
+- compatible: "brcm,bcm2835-smi-dev"
+- smi_handle: a phandle to the smi node.
+
+Optional properties:
+- None.
+
+
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/brcm,bcm2835-smi.txt
@@ -0,0 +1,48 @@
+* Broadcom BCM2835 SMI driver.
+
+SMI or secondary memory interface is a peripheral specific to certain Broadcom
+SOCs, and is helpful for talking to things like parallel-interface displays
+and NAND flashes (in fact, most things with a parallel register interface).
+
+Required properties:
+- compatible: "brcm,bcm2835-smi"
+- reg: Should contain location and length of SMI registers and SMI clkman regs
+- interrupts: *the* SMI interrupt.
+- pinctrl-names: should be "default".
+- pinctrl-0: the phandle of the gpio pin node.
+- brcm,smi-clock-source: the clock source for clkman
+- brcm,smi-clock-divisor: the integer clock divisor for clkman
+- dmas: the dma controller phandle and the DREQ number (4 on a 2835)
+- dma-names: the name used by the driver to request its channel.
+ Should be "rx-tx".
+
+Optional properties:
+- None.
+
+Examples:
+
+8 data pin configuration:
+
+smi: smi@7e600000 {
+ compatible = "brcm,bcm2835-smi";
+ reg = <0x7e600000 0x44>, <0x7e1010b0 0x8>;
+ interrupts = <2 16>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&smi_pins>;
+ brcm,smi-clock-source = <6>;
+ brcm,smi-clock-divisor = <4>;
+ dmas = <&dma 4>;
+ dma-names = "rx-tx";
+
+ status = "okay";
+};
+
+smi_pins: smi_pins {
+ brcm,pins = <2 3 4 5 6 7 8 9 10 11 12 13 14 15>;
+ /* Alt 1: SMI */
+ brcm,function = <5 5 5 5 5 5 5 5 5 5 5 5 5 5>;
+ /* /CS, /WE and /OE are pulled high, as they are
+ generally active low signals */
+ brcm,pull = <2 2 2 2 2 2 0 0 0 0 0 0 0 0>;
+};
+
--- a/drivers/char/broadcom/Kconfig
+++ b/drivers/char/broadcom/Kconfig
@@ -41,3 +41,11 @@ config BCM2835_DEVGPIOMEM
on the 2835. Calling mmap(/dev/gpiomem) will map the GPIO
register page to the user's pointer.
+config BCM2835_SMI_DEV
+ tristate "Character device driver for BCM2835 Secondary Memory Interface"
+ depends on (MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835) && BCM2835_SMI
+ default m
+ help
+ This driver provides a character device interface (ioctl + read/write) to
+ Broadcom's Secondary Memory interface. The low-level functionality is provided
+ by the SMI driver itself.
--- a/drivers/char/broadcom/Makefile
+++ b/drivers/char/broadcom/Makefile
@@ -3,4 +3,4 @@ obj-$(CONFIG_BCM2708_VCMEM) += vc_mem.o
obj-$(CONFIG_BCM_VC_SM) += vc_sm/
obj-$(CONFIG_BCM2835_DEVGPIOMEM)+= bcm2835-gpiomem.o
-
+obj-$(CONFIG_BCM2835_SMI_DEV) += bcm2835_smi_dev.o
--- /dev/null
+++ b/drivers/char/broadcom/bcm2835_smi_dev.c
@@ -0,0 +1,402 @@
+/**
+ * Character device driver for Broadcom Secondary Memory Interface
+ *
+ * Written by Luke Wren <luke@raspberrypi.org>
+ * Copyright (c) 2015, Raspberry Pi (Trading) Ltd.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the above-listed copyright holders may not be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2, as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+
+#include <linux/broadcom/bcm2835_smi.h>
+
+#define DEVICE_NAME "bcm2835-smi-dev"
+#define DRIVER_NAME "smi-dev-bcm2835"
+#define DEVICE_MINOR 0
+
+static struct cdev bcm2835_smi_cdev;
+static dev_t bcm2835_smi_devid;
+static struct class *bcm2835_smi_class;
+static struct device *bcm2835_smi_dev;
+
+struct bcm2835_smi_dev_instance {
+ struct device *dev;
+};
+
+static struct bcm2835_smi_instance *smi_inst;
+static struct bcm2835_smi_dev_instance *inst;
+
+static const char *const ioctl_names[] = {
+ "READ_SETTINGS",
+ "WRITE_SETTINGS",
+ "ADDRESS"
+};
+
+/****************************************************************************
+*
+* SMI chardev file ops
+*
+***************************************************************************/
+static long
+bcm2835_smi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ long ret = 0;
+
+ dev_info(inst->dev, "serving ioctl...");
+
+ switch (cmd) {
+ case BCM2835_SMI_IOC_GET_SETTINGS:{
+ struct smi_settings *settings;
+
+ dev_info(inst->dev, "Reading SMI settings to user.");
+ settings = bcm2835_smi_get_settings_from_regs(smi_inst);
+ if (copy_to_user((void *)arg, settings,
+ sizeof(struct smi_settings)))
+ dev_err(inst->dev, "settings copy failed.");
+ break;
+ }
+ case BCM2835_SMI_IOC_WRITE_SETTINGS:{
+ struct smi_settings *settings;
+
+ dev_info(inst->dev, "Setting user's SMI settings.");
+ settings = bcm2835_smi_get_settings_from_regs(smi_inst);
+ if (copy_from_user(settings, (void *)arg,
+ sizeof(struct smi_settings)))
+ dev_err(inst->dev, "settings copy failed.");
+ else
+ bcm2835_smi_set_regs_from_settings(smi_inst);
+ break;
+ }
+ case BCM2835_SMI_IOC_ADDRESS:
+ dev_info(inst->dev, "SMI address set: 0x%02x", (int)arg);
+ bcm2835_smi_set_address(smi_inst, arg);
+ break;
+ default:
+ dev_err(inst->dev, "invalid ioctl cmd: %d", cmd);
+ ret = -ENOTTY;
+ break;
+ }
+
+ return ret;
+}
+
+static int bcm2835_smi_open(struct inode *inode, struct file *file)
+{
+ int dev = iminor(inode);
+
+ dev_dbg(inst->dev, "SMI device opened.");
+
+ if (dev != DEVICE_MINOR) {
+ dev_err(inst->dev,
+ "bcm2835_smi_release: Unknown minor device: %d",
+ dev);
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int bcm2835_smi_release(struct inode *inode, struct file *file)
+{
+ int dev = iminor(inode);
+
+ if (dev != DEVICE_MINOR) {
+ dev_err(inst->dev,
+ "bcm2835_smi_release: Unknown minor device %d", dev);
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static ssize_t dma_bounce_user(
+ enum dma_transfer_direction dma_dir,
+ char __user *user_ptr,
+ size_t count,
+ struct bcm2835_smi_bounce_info *bounce)
+{
+ int chunk_size;
+ int chunk_no = 0;
+ int count_left = count;
+
+ while (count_left) {
+ int rv;
+ void *buf;
+
+ /* Wait for current chunk to complete: */
+ if (down_timeout(&bounce->callback_sem,
+ msecs_to_jiffies(1000))) {
+ dev_err(inst->dev, "DMA bounce timed out");
+ count -= (count_left);
+ break;
+ }
+
+ if (bounce->callback_sem.count >= DMA_BOUNCE_BUFFER_COUNT - 1)
+ dev_err(inst->dev, "WARNING: Ring buffer overflow");
+ chunk_size = count_left > DMA_BOUNCE_BUFFER_SIZE ?
+ DMA_BOUNCE_BUFFER_SIZE : count_left;
+ buf = bounce->buffer[chunk_no % DMA_BOUNCE_BUFFER_COUNT];
+ if (dma_dir == DMA_DEV_TO_MEM)
+ rv = copy_to_user(user_ptr, buf, chunk_size);
+ else
+ rv = copy_from_user(buf, user_ptr, chunk_size);
+ if (rv)
+ dev_err(inst->dev, "copy_*_user() failed!: %d", rv);
+ user_ptr += chunk_size;
+ count_left -= chunk_size;
+ chunk_no++;
+ }
+ return count;
+}
+
+static ssize_t
+bcm2835_read_file(struct file *f, char __user *user_ptr,
+ size_t count, loff_t *offs)
+{
+ int odd_bytes;
+
+ dev_dbg(inst->dev, "User reading %d bytes from SMI.", count);
+ /* We don't want to DMA a number of bytes % 4 != 0 (32 bit FIFO) */
+ if (count > DMA_THRESHOLD_BYTES)
+ odd_bytes = count & 0x3;
+ else
+ odd_bytes = count;
+ count -= odd_bytes;
+ if (count) {
+ struct bcm2835_smi_bounce_info *bounce;
+
+ count = bcm2835_smi_user_dma(smi_inst,
+ DMA_DEV_TO_MEM, user_ptr, count,
+ &bounce);
+ if (count)
+ count = dma_bounce_user(DMA_DEV_TO_MEM, user_ptr,
+ count, bounce);
+ }
+ if (odd_bytes) {
+ /* Read from FIFO directly if not using DMA */
+ uint8_t buf[DMA_THRESHOLD_BYTES];
+
+ bcm2835_smi_read_buf(smi_inst, buf, odd_bytes);
+ if (copy_to_user(user_ptr, buf, odd_bytes))
+ dev_err(inst->dev, "copy_to_user() failed.");
+ count += odd_bytes;
+
+ }
+ return count;
+}
+
+static ssize_t
+bcm2835_write_file(struct file *f, const char __user *user_ptr,
+ size_t count, loff_t *offs)
+{
+ int odd_bytes;
+
+ dev_dbg(inst->dev, "User writing %d bytes to SMI.", count);
+ if (count > DMA_THRESHOLD_BYTES)
+ odd_bytes = count & 0x3;
+ else
+ odd_bytes = count;
+ count -= odd_bytes;
+ if (count) {
+ struct bcm2835_smi_bounce_info *bounce;
+
+ count = bcm2835_smi_user_dma(smi_inst,
+ DMA_MEM_TO_DEV, (char __user *)user_ptr, count,
+ &bounce);
+ if (count)
+ count = dma_bounce_user(DMA_MEM_TO_DEV,
+ (char __user *)user_ptr,
+ count, bounce);
+ }
+ if (odd_bytes) {
+ uint8_t buf[DMA_THRESHOLD_BYTES];
+
+ if (copy_from_user(buf, user_ptr, odd_bytes))
+ dev_err(inst->dev, "copy_from_user() failed.");
+ else
+ bcm2835_smi_write_buf(smi_inst, buf, odd_bytes);
+ count += odd_bytes;
+ }
+ return count;
+}
+
+static const struct file_operations
+bcm2835_smi_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = bcm2835_smi_ioctl,
+ .open = bcm2835_smi_open,
+ .release = bcm2835_smi_release,
+ .read = bcm2835_read_file,
+ .write = bcm2835_write_file,
+};
+
+
+/****************************************************************************
+*
+* bcm2835_smi_probe - called when the driver is loaded.
+*
+***************************************************************************/
+
+static int bcm2835_smi_dev_probe(struct platform_device *pdev)
+{
+ int err;
+ void *ptr_err;
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node, *smi_node;
+
+ if (!node) {
+ dev_err(dev, "No device tree node supplied!");
+ return -EINVAL;
+ }
+
+ smi_node = of_parse_phandle(node, "smi_handle", 0);
+
+ if (!smi_node) {
+ dev_err(dev, "No such property: smi_handle");
+ return -ENXIO;
+ }
+
+ smi_inst = bcm2835_smi_get(smi_node);
+
+ if (!smi_inst)
+ return -EPROBE_DEFER;
+
+ /* Allocate buffers and instance data */
+
+ inst = devm_kzalloc(dev, sizeof(*inst), GFP_KERNEL);
+
+ if (!inst)
+ return -ENOMEM;
+
+ inst->dev = dev;
+
+ /* Create character device entries */
+
+ err = alloc_chrdev_region(&bcm2835_smi_devid,
+ DEVICE_MINOR, 1, DEVICE_NAME);
+ if (err != 0) {
+ dev_err(inst->dev, "unable to allocate device number");
+ return -ENOMEM;
+ }
+ cdev_init(&bcm2835_smi_cdev, &bcm2835_smi_fops);
+ bcm2835_smi_cdev.owner = THIS_MODULE;
+ err = cdev_add(&bcm2835_smi_cdev, bcm2835_smi_devid, 1);
+ if (err != 0) {
+ dev_err(inst->dev, "unable to register device");
+ err = -ENOMEM;
+ goto failed_cdev_add;
+ }
+
+ /* Create sysfs entries */
+
+ bcm2835_smi_class = class_create(THIS_MODULE, DEVICE_NAME);
+ ptr_err = bcm2835_smi_class;
+ if (IS_ERR(ptr_err))
+ goto failed_class_create;
+
+ bcm2835_smi_dev = device_create(bcm2835_smi_class, NULL,
+ bcm2835_smi_devid, NULL,
+ "smi");
+ ptr_err = bcm2835_smi_dev;
+ if (IS_ERR(ptr_err))
+ goto failed_device_create;
+
+ dev_info(inst->dev, "initialised");
+
+ return 0;
+
+failed_device_create:
+ class_destroy(bcm2835_smi_class);
+failed_class_create:
+ cdev_del(&bcm2835_smi_cdev);
+ err = PTR_ERR(ptr_err);
+failed_cdev_add:
+ unregister_chrdev_region(bcm2835_smi_devid, 1);
+ dev_err(dev, "could not load bcm2835_smi_dev");
+ return err;
+}
+
+/****************************************************************************
+*
+* bcm2835_smi_remove - called when the driver is unloaded.
+*
+***************************************************************************/
+
+static int bcm2835_smi_dev_remove(struct platform_device *pdev)
+{
+ device_destroy(bcm2835_smi_class, bcm2835_smi_devid);
+ class_destroy(bcm2835_smi_class);
+ cdev_del(&bcm2835_smi_cdev);
+ unregister_chrdev_region(bcm2835_smi_devid, 1);
+
+ dev_info(inst->dev, "SMI character dev removed - OK");
+ return 0;
+}
+
+/****************************************************************************
+*
+* Register the driver with device tree
+*
+***************************************************************************/
+
+static const struct of_device_id bcm2835_smi_dev_of_match[] = {
+ {.compatible = "brcm,bcm2835-smi-dev",},
+ { /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, bcm2835_smi_dev_of_match);
+
+static struct platform_driver bcm2835_smi_dev_driver = {
+ .probe = bcm2835_smi_dev_probe,
+ .remove = bcm2835_smi_dev_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = bcm2835_smi_dev_of_match,
+ },
+};
+
+module_platform_driver(bcm2835_smi_dev_driver);
+
+MODULE_ALIAS("platform:smi-dev-bcm2835");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION(
+ "Character device driver for BCM2835's secondary memory interface");
+MODULE_AUTHOR("Luke Wren <luke@raspberrypi.org>");
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -10,6 +10,14 @@ config SENSORS_LIS3LV02D
select INPUT_POLLDEV
default n
+config BCM2835_SMI
+ tristate "Broadcom 283x Secondary Memory Interface driver"
+ depends on MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835
+ default m
+ help
+ Driver for enabling and using Broadcom's Secondary/Slow Memory Interface.
+ Appears as /dev/bcm2835_smi. For ioctl interface see drivers/misc/bcm2835_smi.h
+
config AD525X_DPOT
tristate "Analog Devices Digital Potentiometers"
depends on (I2C || SPI) && SYSFS
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_AD525X_DPOT_SPI) += ad525x_
obj-$(CONFIG_INTEL_MID_PTI) += pti.o
obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o
obj-$(CONFIG_ATMEL_TCLIB) += atmel_tclib.o
+obj-$(CONFIG_BCM2835_SMI) += bcm2835_smi.o
obj-$(CONFIG_BMP085) += bmp085.o
obj-$(CONFIG_BMP085_I2C) += bmp085-i2c.o
obj-$(CONFIG_BMP085_SPI) += bmp085-spi.o
--- /dev/null
+++ b/drivers/misc/bcm2835_smi.c
@@ -0,0 +1,985 @@
+/**
+ * Broadcom Secondary Memory Interface driver
+ *
+ * Written by Luke Wren <luke@raspberrypi.org>
+ * Copyright (c) 2015, Raspberry Pi (Trading) Ltd.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the above-listed copyright holders may not be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2, as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+
+#define BCM2835_SMI_IMPLEMENTATION
+#include <linux/broadcom/bcm2835_smi.h>
+
+#define DRIVER_NAME "smi-bcm2835"
+
+#define N_PAGES_FROM_BYTES(n) ((n + PAGE_SIZE-1) / PAGE_SIZE)
+
+#define DMA_WRITE_TO_MEM true
+#define DMA_READ_FROM_MEM false
+
+struct bcm2835_smi_instance {
+ struct device *dev;
+ struct smi_settings settings;
+ __iomem void *smi_regs_ptr, *cm_smi_regs_ptr;
+ dma_addr_t smi_regs_busaddr;
+
+ struct dma_chan *dma_chan;
+ struct dma_slave_config dma_config;
+
+ struct bcm2835_smi_bounce_info bounce;
+
+ struct scatterlist buffer_sgl;
+
+ int clock_source;
+ int clock_divisor;
+
+ /* Sometimes we are called into in an atomic context (e.g. by
+ JFFS2 + MTD) so we can't use a mutex */
+ spinlock_t transaction_lock;
+};
+
+/****************************************************************************
+*
+* SMI clock manager setup
+*
+***************************************************************************/
+
+static inline void write_smi_cm_reg(struct bcm2835_smi_instance *inst,
+ u32 val, unsigned reg)
+{
+ writel(CM_PWD | val, inst->cm_smi_regs_ptr + reg);
+}
+
+static inline u32 read_smi_cm_reg(struct bcm2835_smi_instance *inst,
+ unsigned reg)
+{
+ return readl(inst->cm_smi_regs_ptr + reg);
+}
+
+static void smi_setup_clock(struct bcm2835_smi_instance *inst)
+{
+ dev_dbg(inst->dev, "Setting up clock...");
+ /* Disable SMI clock and wait for it to stop. */
+ write_smi_cm_reg(inst, 0, CM_SMI_CTL);
+ while (read_smi_cm_reg(inst, CM_SMI_CTL) & CM_SMI_CTL_BUSY)
+ ;
+
+ write_smi_cm_reg(inst, (inst->clock_divisor << CM_SMI_DIV_DIVI_OFFS),
+ CM_SMI_DIV);
+ write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS),
+ CM_SMI_CTL);
+
+ /* Enable the clock */
+ write_smi_cm_reg(inst, (inst->clock_source << CM_SMI_CTL_SRC_OFFS) |
+ CM_SMI_CTL_ENAB, CM_SMI_CTL);
+}
+
+/****************************************************************************
+*
+* SMI peripheral setup
+*
+***************************************************************************/
+
+static inline void write_smi_reg(struct bcm2835_smi_instance *inst,
+ u32 val, unsigned reg)
+{
+ writel(val, inst->smi_regs_ptr + reg);
+}
+
+static inline u32 read_smi_reg(struct bcm2835_smi_instance *inst, unsigned reg)
+{
+ return readl(inst->smi_regs_ptr + reg);
+}
+
+/* Token-paste macro for e.g SMIDSR_RSTROBE -> value of SMIDSR_RSTROBE_MASK */
+#define _CONCAT(x, y) x##y
+#define CONCAT(x, y) _CONCAT(x, y)
+
+#define SET_BIT_FIELD(dest, field, bits) ((dest) = \
+ ((dest) & ~CONCAT(field, _MASK)) | (((bits) << CONCAT(field, _OFFS))& \
+ CONCAT(field, _MASK)))
+#define GET_BIT_FIELD(src, field) (((src) & \
+ CONCAT(field, _MASK)) >> CONCAT(field, _OFFS))
+
+static void smi_dump_context_labelled(struct bcm2835_smi_instance *inst,
+ const char *label)
+{
+ dev_err(inst->dev, "SMI context dump: %s", label);
+ dev_err(inst->dev, "SMICS: 0x%08x", read_smi_reg(inst, SMICS));
+ dev_err(inst->dev, "SMIL: 0x%08x", read_smi_reg(inst, SMIL));
+ dev_err(inst->dev, "SMIDSR: 0x%08x", read_smi_reg(inst, SMIDSR0));
+ dev_err(inst->dev, "SMIDSW: 0x%08x", read_smi_reg(inst, SMIDSW0));
+ dev_err(inst->dev, "SMIDC: 0x%08x", read_smi_reg(inst, SMIDC));
+ dev_err(inst->dev, "SMIFD: 0x%08x", read_smi_reg(inst, SMIFD));
+ dev_err(inst->dev, " ");
+}
+
+static inline void smi_dump_context(struct bcm2835_smi_instance *inst)
+{
+ smi_dump_context_labelled(inst, "");
+}
+
+static void smi_get_default_settings(struct bcm2835_smi_instance *inst)
+{
+ struct smi_settings *settings = &inst->settings;
+
+ settings->data_width = SMI_WIDTH_16BIT;
+ settings->pack_data = true;
+
+ settings->read_setup_time = 1;
+ settings->read_hold_time = 1;
+ settings->read_pace_time = 1;
+ settings->read_strobe_time = 3;
+
+ settings->write_setup_time = settings->read_setup_time;
+ settings->write_hold_time = settings->read_hold_time;
+ settings->write_pace_time = settings->read_pace_time;
+ settings->write_strobe_time = settings->read_strobe_time;
+
+ settings->dma_enable = true;
+ settings->dma_passthrough_enable = false;
+ settings->dma_read_thresh = 0x01;
+ settings->dma_write_thresh = 0x3f;
+ settings->dma_panic_read_thresh = 0x20;
+ settings->dma_panic_write_thresh = 0x20;
+}
+
+void bcm2835_smi_set_regs_from_settings(struct bcm2835_smi_instance *inst)
+{
+ struct smi_settings *settings = &inst->settings;
+ int smidsr_temp = 0, smidsw_temp = 0, smics_temp,
+ smidcs_temp, smidc_temp = 0;
+
+ spin_lock(&inst->transaction_lock);
+
+ /* temporarily disable the peripheral: */
+ smics_temp = read_smi_reg(inst, SMICS);
+ write_smi_reg(inst, 0, SMICS);
+ smidcs_temp = read_smi_reg(inst, SMIDCS);
+ write_smi_reg(inst, 0, SMIDCS);
+
+ if (settings->pack_data)
+ smics_temp |= SMICS_PXLDAT;
+ else
+ smics_temp &= ~SMICS_PXLDAT;
+
+ SET_BIT_FIELD(smidsr_temp, SMIDSR_RWIDTH, settings->data_width);
+ SET_BIT_FIELD(smidsr_temp, SMIDSR_RSETUP, settings->read_setup_time);
+ SET_BIT_FIELD(smidsr_temp, SMIDSR_RHOLD, settings->read_hold_time);
+ SET_BIT_FIELD(smidsr_temp, SMIDSR_RPACE, settings->read_pace_time);
+ SET_BIT_FIELD(smidsr_temp, SMIDSR_RSTROBE, settings->read_strobe_time);
+ write_smi_reg(inst, smidsr_temp, SMIDSR0);
+
+ SET_BIT_FIELD(smidsw_temp, SMIDSW_WWIDTH, settings->data_width);
+ if (settings->data_width == SMI_WIDTH_8BIT)
+ smidsw_temp |= SMIDSW_WSWAP;
+ else
+ smidsw_temp &= ~SMIDSW_WSWAP;
+ SET_BIT_FIELD(smidsw_temp, SMIDSW_WSETUP, settings->write_setup_time);
+ SET_BIT_FIELD(smidsw_temp, SMIDSW_WHOLD, settings->write_hold_time);
+ SET_BIT_FIELD(smidsw_temp, SMIDSW_WPACE, settings->write_pace_time);
+ SET_BIT_FIELD(smidsw_temp, SMIDSW_WSTROBE,
+ settings->write_strobe_time);
+ write_smi_reg(inst, smidsw_temp, SMIDSW0);
+
+ SET_BIT_FIELD(smidc_temp, SMIDC_REQR, settings->dma_read_thresh);
+ SET_BIT_FIELD(smidc_temp, SMIDC_REQW, settings->dma_write_thresh);
+ SET_BIT_FIELD(smidc_temp, SMIDC_PANICR,
+ settings->dma_panic_read_thresh);
+ SET_BIT_FIELD(smidc_temp, SMIDC_PANICW,
+ settings->dma_panic_write_thresh);
+ if (settings->dma_passthrough_enable) {
+ smidc_temp |= SMIDC_DMAP;
+ smidsr_temp |= SMIDSR_RDREQ;
+ write_smi_reg(inst, smidsr_temp, SMIDSR0);
+ smidsw_temp |= SMIDSW_WDREQ;
+ write_smi_reg(inst, smidsw_temp, SMIDSW0);
+ } else
+ smidc_temp &= ~SMIDC_DMAP;
+ if (settings->dma_enable)
+ smidc_temp |= SMIDC_DMAEN;
+ else
+ smidc_temp &= ~SMIDC_DMAEN;
+
+ write_smi_reg(inst, smidc_temp, SMIDC);
+
+ /* re-enable (if was previously enabled) */
+ write_smi_reg(inst, smics_temp, SMICS);
+ write_smi_reg(inst, smidcs_temp, SMIDCS);
+
+ spin_unlock(&inst->transaction_lock);
+}
+EXPORT_SYMBOL(bcm2835_smi_set_regs_from_settings);
+
+struct smi_settings *bcm2835_smi_get_settings_from_regs
+ (struct bcm2835_smi_instance *inst)
+{
+ struct smi_settings *settings = &inst->settings;
+ int smidsr, smidsw, smidc;
+
+ spin_lock(&inst->transaction_lock);
+
+ smidsr = read_smi_reg(inst, SMIDSR0);
+ smidsw = read_smi_reg(inst, SMIDSW0);
+ smidc = read_smi_reg(inst, SMIDC);
+
+ settings->pack_data = (read_smi_reg(inst, SMICS) & SMICS_PXLDAT) ?
+ true : false;
+
+ settings->data_width = GET_BIT_FIELD(smidsr, SMIDSR_RWIDTH);
+ settings->read_setup_time = GET_BIT_FIELD(smidsr, SMIDSR_RSETUP);
+ settings->read_hold_time = GET_BIT_FIELD(smidsr, SMIDSR_RHOLD);
+ settings->read_pace_time = GET_BIT_FIELD(smidsr, SMIDSR_RPACE);
+ settings->read_strobe_time = GET_BIT_FIELD(smidsr, SMIDSR_RSTROBE);
+
+ settings->write_setup_time = GET_BIT_FIELD(smidsw, SMIDSW_WSETUP);
+ settings->write_hold_time = GET_BIT_FIELD(smidsw, SMIDSW_WHOLD);
+ settings->write_pace_time = GET_BIT_FIELD(smidsw, SMIDSW_WPACE);
+ settings->write_strobe_time = GET_BIT_FIELD(smidsw, SMIDSW_WSTROBE);
+
+ settings->dma_read_thresh = GET_BIT_FIELD(smidc, SMIDC_REQR);
+ settings->dma_write_thresh = GET_BIT_FIELD(smidc, SMIDC_REQW);
+ settings->dma_panic_read_thresh = GET_BIT_FIELD(smidc, SMIDC_PANICR);
+ settings->dma_panic_write_thresh = GET_BIT_FIELD(smidc, SMIDC_PANICW);
+ settings->dma_passthrough_enable = (smidc & SMIDC_DMAP) ? true : false;
+ settings->dma_enable = (smidc & SMIDC_DMAEN) ? true : false;
+
+ spin_unlock(&inst->transaction_lock);
+
+ return settings;
+}
+EXPORT_SYMBOL(bcm2835_smi_get_settings_from_regs);
+
+static inline void smi_set_address(struct bcm2835_smi_instance *inst,
+ unsigned int address)
+{
+ int smia_temp = 0, smida_temp = 0;
+
+ SET_BIT_FIELD(smia_temp, SMIA_ADDR, address);
+ SET_BIT_FIELD(smida_temp, SMIDA_ADDR, address);
+
+ /* Write to both address registers - user doesn't care whether we're
+ doing programmed or direct transfers. */
+ write_smi_reg(inst, smia_temp, SMIA);
+ write_smi_reg(inst, smida_temp, SMIDA);
+}
+
+static void smi_setup_regs(struct bcm2835_smi_instance *inst)
+{
+
+ dev_dbg(inst->dev, "Initialising SMI registers...");
+ /* Disable the peripheral if already enabled */
+ write_smi_reg(inst, 0, SMICS);
+ write_smi_reg(inst, 0, SMIDCS);
+
+ smi_get_default_settings(inst);
+ bcm2835_smi_set_regs_from_settings(inst);
+ smi_set_address(inst, 0);
+
+ write_smi_reg(inst, read_smi_reg(inst, SMICS) | SMICS_ENABLE, SMICS);
+ write_smi_reg(inst, read_smi_reg(inst, SMIDCS) | SMIDCS_ENABLE,
+ SMIDCS);
+}
+
+/****************************************************************************
+*
+* Low-level SMI access functions
+* Other modules should use the exported higher-level functions e.g.
+* bcm2835_smi_write_buf() unless they have a good reason to use these
+*
+***************************************************************************/
+
+static inline uint32_t smi_read_single_word(struct bcm2835_smi_instance *inst)
+{
+ int timeout = 0;
+
+ write_smi_reg(inst, SMIDCS_ENABLE, SMIDCS);
+ write_smi_reg(inst, SMIDCS_ENABLE | SMIDCS_START, SMIDCS);
+ /* Make sure things happen in the right order...*/
+ mb();
+ while (!(read_smi_reg(inst, SMIDCS) & SMIDCS_DONE) &&
+ ++timeout < 10000)
+ ;
+ if (timeout < 10000)
+ return read_smi_reg(inst, SMIDD);
+
+ dev_err(inst->dev,
+ "SMI direct read timed out (is the clock set up correctly?)");
+ return 0;
+}
+
+static inline void smi_write_single_word(struct bcm2835_smi_instance *inst,
+ uint32_t data)
+{
+ int timeout = 0;
+
+ write_smi_reg(inst, SMIDCS_ENABLE | SMIDCS_WRITE, SMIDCS);
+ write_smi_reg(inst, data, SMIDD);
+ write_smi_reg(inst, SMIDCS_ENABLE | SMIDCS_WRITE | SMIDCS_START,
+ SMIDCS);
+
+ while (!(read_smi_reg(inst, SMIDCS) & SMIDCS_DONE) &&
+ ++timeout < 10000)
+ ;
+ if (timeout >= 10000)
+ dev_err(inst->dev,
+ "SMI direct write timed out (is the clock set up correctly?)");
+}
+
+/* Initiates a programmed read into the read FIFO. It is up to the caller to
+ * read data from the FIFO - either via paced DMA transfer,
+ * or polling SMICS_RXD to check whether data is available.
+ * SMICS_ACTIVE will go low upon completion. */
+static void smi_init_programmed_read(struct bcm2835_smi_instance *inst,
+ int num_transfers)
+{
+ int smics_temp;
+
+ /* Disable the peripheral: */
+ smics_temp = read_smi_reg(inst, SMICS) & ~(SMICS_ENABLE | SMICS_WRITE);
+ write_smi_reg(inst, smics_temp, SMICS);
+ while (read_smi_reg(inst, SMICS) & SMICS_ENABLE)
+ ;
+
+ /* Program the transfer count: */
+ write_smi_reg(inst, num_transfers, SMIL);
+
+ /* re-enable and start: */
+ smics_temp |= SMICS_ENABLE;
+ write_smi_reg(inst, smics_temp, SMICS);
+ smics_temp |= SMICS_CLEAR;
+ /* Just to be certain: */
+ mb();
+ while (read_smi_reg(inst, SMICS) & SMICS_ACTIVE)
+ ;
+ write_smi_reg(inst, smics_temp, SMICS);
+ smics_temp |= SMICS_START;
+ write_smi_reg(inst, smics_temp, SMICS);
+}
+
+/* Initiates a programmed write sequence, using data from the write FIFO.
+ * It is up to the caller to initiate a DMA transfer before calling,
+ * or use another method to keep the write FIFO topped up.
+ * SMICS_ACTIVE will go low upon completion.
+ */
+static void smi_init_programmed_write(struct bcm2835_smi_instance *inst,
+ int num_transfers)
+{
+ int smics_temp;
+
+ /* Disable the peripheral: */
+ smics_temp = read_smi_reg(inst, SMICS) & ~SMICS_ENABLE;
+ write_smi_reg(inst, smics_temp, SMICS);
+ while (read_smi_reg(inst, SMICS) & SMICS_ENABLE)
+ ;
+
+ /* Program the transfer count: */
+ write_smi_reg(inst, num_transfers, SMIL);
+
+ /* setup, re-enable and start: */
+ smics_temp |= SMICS_WRITE | SMICS_ENABLE;
+ write_smi_reg(inst, smics_temp, SMICS);
+ smics_temp |= SMICS_START;
+ write_smi_reg(inst, smics_temp, SMICS);
+}
+
+/* Initiate a read and then poll FIFO for data, reading out as it appears. */
+static void smi_read_fifo(struct bcm2835_smi_instance *inst,
+ uint32_t *dest, int n_bytes)
+{
+ if (read_smi_reg(inst, SMICS) & SMICS_RXD) {
+ smi_dump_context_labelled(inst,
+ "WARNING: read FIFO not empty at start of read call.");
+ while (read_smi_reg(inst, SMICS))
+ ;
+ }
+
+ /* Dispatch the read: */
+ if (inst->settings.data_width == SMI_WIDTH_8BIT)
+ smi_init_programmed_read(inst, n_bytes);
+ else if (inst->settings.data_width == SMI_WIDTH_16BIT)
+ smi_init_programmed_read(inst, n_bytes / 2);
+ else {
+ dev_err(inst->dev, "Unsupported data width for read.");
+ return;
+ }
+
+ /* Poll FIFO to keep it empty */
+ while (!(read_smi_reg(inst, SMICS) & SMICS_DONE))
+ if (read_smi_reg(inst, SMICS) & SMICS_RXD)
+ *dest++ = read_smi_reg(inst, SMID);
+
+ /* Ensure that the FIFO is emptied */
+ if (read_smi_reg(inst, SMICS) & SMICS_RXD) {
+ int fifo_count;
+
+ fifo_count = GET_BIT_FIELD(read_smi_reg(inst, SMIFD),
+ SMIFD_FCNT);
+ while (fifo_count--)
+ *dest++ = read_smi_reg(inst, SMID);
+ }
+
+ if (!(read_smi_reg(inst, SMICS) & SMICS_DONE))
+ smi_dump_context_labelled(inst,
+ "WARNING: transaction finished but done bit not set.");
+
+ if (read_smi_reg(inst, SMICS) & SMICS_RXD)
+ smi_dump_context_labelled(inst,
+ "WARNING: read FIFO not empty at end of read call.");
+
+}
+
+/* Initiate a write, and then keep the FIFO topped up. */
+static void smi_write_fifo(struct bcm2835_smi_instance *inst,
+ uint32_t *src, int n_bytes)
+{
+ int i, timeout = 0;
+
+ /* Empty FIFOs if not already so */
+ if (!(read_smi_reg(inst, SMICS) & SMICS_TXE)) {
+ smi_dump_context_labelled(inst,
+ "WARNING: write fifo not empty at start of write call.");
+ write_smi_reg(inst, read_smi_reg(inst, SMICS) | SMICS_CLEAR,
+ SMICS);
+ }
+
+ /* Initiate the transfer */
+ if (inst->settings.data_width == SMI_WIDTH_8BIT)
+ smi_init_programmed_write(inst, n_bytes);
+ else if (inst->settings.data_width == SMI_WIDTH_16BIT)
+ smi_init_programmed_write(inst, n_bytes / 2);
+ else {
+ dev_err(inst->dev, "Unsupported data width for write.");
+ return;
+ }
+ /* Fill the FIFO: */
+ for (i = 0; i < (n_bytes - 1) / 4 + 1; ++i) {
+ while (!(read_smi_reg(inst, SMICS) & SMICS_TXD))
+ ;
+ write_smi_reg(inst, *src++, SMID);
+ }
+ /* Busy wait... */
+ while (!(read_smi_reg(inst, SMICS) & SMICS_DONE) && ++timeout <
+ 1000000)
+ ;
+ if (timeout >= 1000000)
+ smi_dump_context_labelled(inst,
+ "Timed out on write operation!");
+ if (!(read_smi_reg(inst, SMICS) & SMICS_TXE))
+ smi_dump_context_labelled(inst,
+ "WARNING: FIFO not empty at end of write operation.");
+}
+
+/****************************************************************************
+*
+* SMI DMA operations
+*
+***************************************************************************/
+
+/* Disable SMI and put it into the correct direction before doing DMA setup.
+ Stops spurious DREQs during setup. Peripheral is re-enabled by init_*() */
+static void smi_disable(struct bcm2835_smi_instance *inst,
+ enum dma_transfer_direction direction)
+{
+ int smics_temp = read_smi_reg(inst, SMICS) & ~SMICS_ENABLE;
+
+ if (direction == DMA_DEV_TO_MEM)
+ smics_temp &= ~SMICS_WRITE;
+ else
+ smics_temp |= SMICS_WRITE;
+ write_smi_reg(inst, smics_temp, SMICS);
+ while (read_smi_reg(inst, SMICS) & SMICS_ACTIVE)
+ ;
+}
+
+static struct scatterlist *smi_scatterlist_from_buffer(
+ struct bcm2835_smi_instance *inst,
+ dma_addr_t buf,
+ size_t len,
+ struct scatterlist *sg)
+{
+ sg_init_table(sg, 1);
+ sg_dma_address(sg) = buf;
+ sg_dma_len(sg) = len;
+ return sg;
+}
+
+static void smi_dma_callback_user_copy(void *param)
+{
+ /* Notify the bottom half that a chunk is ready for user copy */
+ struct bcm2835_smi_instance *inst =
+ (struct bcm2835_smi_instance *)param;
+
+ up(&inst->bounce.callback_sem);
+}
+
+/* Creates a descriptor, assigns the given callback, and submits the
+ descriptor to dmaengine. Does not block - can queue up multiple
+ descriptors and then wait for them all to complete.
+ sg_len is the number of control blocks, NOT the number of bytes.
+ dir can be DMA_MEM_TO_DEV or DMA_DEV_TO_MEM.
+ callback can be NULL - in this case it is not called. */
+static inline struct dma_async_tx_descriptor *smi_dma_submit_sgl(
+ struct bcm2835_smi_instance *inst,
+ struct scatterlist *sgl,
+ size_t sg_len,
+ enum dma_transfer_direction dir,
+ dma_async_tx_callback callback)
+{
+ struct dma_async_tx_descriptor *desc;
+
+ desc = dmaengine_prep_slave_sg(inst->dma_chan,
+ sgl,
+ sg_len,
+ dir,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK |
+ DMA_PREP_FENCE);
+ if (!desc) {
+ dev_err(inst->dev, "read_sgl: dma slave preparation failed!");
+ write_smi_reg(inst, read_smi_reg(inst, SMICS) & ~SMICS_ACTIVE,
+ SMICS);
+ while (read_smi_reg(inst, SMICS) & SMICS_ACTIVE)
+ cpu_relax();
+ write_smi_reg(inst, read_smi_reg(inst, SMICS) | SMICS_ACTIVE,
+ SMICS);
+ return NULL;
+ }
+ desc->callback = callback;
+ desc->callback_param = inst;
+ if (dmaengine_submit(desc) < 0)
+ return NULL;
+ return desc;
+}
+
+/* NB this function blocks until the transfer is complete */
+static void
+smi_dma_read_sgl(struct bcm2835_smi_instance *inst,
+ struct scatterlist *sgl, size_t sg_len, size_t n_bytes)
+{
+ struct dma_async_tx_descriptor *desc;
+
+ /* Disable SMI and set to read before dispatching DMA - if SMI is in
+ * write mode and TX fifo is empty, it will generate a DREQ which may
+ * cause the read DMA to complete before the SMI read command is even
+ * dispatched! We want to dispatch DMA before SMI read so that reading
+ * is gapless, for logic analyser.
+ */
+
+ smi_disable(inst, DMA_DEV_TO_MEM);
+
+ desc = smi_dma_submit_sgl(inst, sgl, sg_len, DMA_DEV_TO_MEM, NULL);
+ dma_async_issue_pending(inst->dma_chan);
+
+ if (inst->settings.data_width == SMI_WIDTH_8BIT)
+ smi_init_programmed_read(inst, n_bytes);
+ else
+ smi_init_programmed_read(inst, n_bytes / 2);
+
+ if (dma_wait_for_async_tx(desc) == DMA_ERROR)
+ smi_dump_context_labelled(inst, "DMA timeout!");
+}
+
+static void
+smi_dma_write_sgl(struct bcm2835_smi_instance *inst,
+ struct scatterlist *sgl, size_t sg_len, size_t n_bytes)
+{
+ struct dma_async_tx_descriptor *desc;
+
+ if (inst->settings.data_width == SMI_WIDTH_8BIT)
+ smi_init_programmed_write(inst, n_bytes);
+ else
+ smi_init_programmed_write(inst, n_bytes / 2);
+
+ desc = smi_dma_submit_sgl(inst, sgl, sg_len, DMA_MEM_TO_DEV, NULL);
+ dma_async_issue_pending(inst->dma_chan);
+
+ if (dma_wait_for_async_tx(desc) == DMA_ERROR)
+ smi_dump_context_labelled(inst, "DMA timeout!");
+ else
+ /* Wait for SMI to finish our writes */
+ while (!(read_smi_reg(inst, SMICS) & SMICS_DONE))
+ cpu_relax();
+}
+
+ssize_t bcm2835_smi_user_dma(
+ struct bcm2835_smi_instance *inst,
+ enum dma_transfer_direction dma_dir,
+ char __user *user_ptr, size_t count,
+ struct bcm2835_smi_bounce_info **bounce)
+{
+ int chunk_no = 0, chunk_size, count_left = count;
+ struct scatterlist *sgl;
+ void (*init_trans_func)(struct bcm2835_smi_instance *, int);
+
+ spin_lock(&inst->transaction_lock);
+
+ if (dma_dir == DMA_DEV_TO_MEM)
+ init_trans_func = smi_init_programmed_read;
+ else
+ init_trans_func = smi_init_programmed_write;
+
+ smi_disable(inst, dma_dir);
+
+ sema_init(&inst->bounce.callback_sem, 0);
+ if (bounce)
+ *bounce = &inst->bounce;
+ while (count_left) {
+ chunk_size = count_left > DMA_BOUNCE_BUFFER_SIZE ?
+ DMA_BOUNCE_BUFFER_SIZE : count_left;
+ if (chunk_size == DMA_BOUNCE_BUFFER_SIZE) {
+ sgl =
+ &inst->bounce.sgl[chunk_no % DMA_BOUNCE_BUFFER_COUNT];
+ } else {
+ sgl = smi_scatterlist_from_buffer(
+ inst,
+ inst->bounce.phys[
+ chunk_no % DMA_BOUNCE_BUFFER_COUNT],
+ chunk_size,
+ &inst->buffer_sgl);
+ }
+
+ if (!smi_dma_submit_sgl(inst, sgl, 1, dma_dir,
+ smi_dma_callback_user_copy
+ )) {
+ dev_err(inst->dev, "sgl submit failed");
+ count = 0;
+ goto out;
+ }
+ count_left -= chunk_size;
+ chunk_no++;
+ }
+ dma_async_issue_pending(inst->dma_chan);
+
+ if (inst->settings.data_width == SMI_WIDTH_8BIT)
+ init_trans_func(inst, count);
+ else if (inst->settings.data_width == SMI_WIDTH_16BIT)
+ init_trans_func(inst, count / 2);
+out:
+ spin_unlock(&inst->transaction_lock);
+ return count;
+}
+EXPORT_SYMBOL(bcm2835_smi_user_dma);
+
+
+/****************************************************************************
+*
+* High level buffer transfer functions - for use by other drivers
+*
+***************************************************************************/
+
+/* Buffer must be physically contiguous - i.e. kmalloc, not vmalloc! */
+void bcm2835_smi_write_buf(
+ struct bcm2835_smi_instance *inst,
+ const void *buf, size_t n_bytes)
+{
+ int odd_bytes = n_bytes & 0x3;
+
+ n_bytes -= odd_bytes;
+
+ spin_lock(&inst->transaction_lock);
+
+ if (n_bytes > DMA_THRESHOLD_BYTES) {
+ dma_addr_t phy_addr = dma_map_single(
+ inst->dev,
+ (void *)buf,
+ n_bytes,
+ DMA_MEM_TO_DEV);
+ struct scatterlist *sgl =
+ smi_scatterlist_from_buffer(inst, phy_addr, n_bytes,
+ &inst->buffer_sgl);
+
+ if (!sgl) {
+ smi_dump_context_labelled(inst,
+ "Error: could not create scatterlist for write!");
+ goto out;
+ }
+ smi_dma_write_sgl(inst, sgl, 1, n_bytes);
+
+ dma_unmap_single
+ (inst->dev, phy_addr, n_bytes, DMA_MEM_TO_DEV);
+ } else if (n_bytes) {
+ smi_write_fifo(inst, (uint32_t *) buf, n_bytes);
+ }
+ buf += n_bytes;
+
+ if (inst->settings.data_width == SMI_WIDTH_8BIT) {
+ while (odd_bytes--)
+ smi_write_single_word(inst, *(uint8_t *) (buf++));
+ } else {
+ while (odd_bytes >= 2) {
+ smi_write_single_word(inst, *(uint16_t *)buf);
+ buf += 2;
+ odd_bytes -= 2;
+ }
+ if (odd_bytes) {
+ /* Reading an odd number of bytes on a 16 bit bus is
+ a user bug. It's kinder to fail early and tell them
+ than to e.g. transparently give them the bottom byte
+ of a 16 bit transfer. */
+ dev_err(inst->dev,
+ "WARNING: odd number of bytes specified for wide transfer.");
+ dev_err(inst->dev,
+ "At least one byte dropped as a result.");
+ dump_stack();
+ }
+ }
+out:
+ spin_unlock(&inst->transaction_lock);
+}
+EXPORT_SYMBOL(bcm2835_smi_write_buf);
+
+void bcm2835_smi_read_buf(struct bcm2835_smi_instance *inst,
+ void *buf, size_t n_bytes)
+{
+
+ /* SMI is inherently 32-bit, which causes surprising amounts of mess
+ for bytes % 4 != 0. Easiest to avoid this mess altogether
+ by handling remainder separately. */
+ int odd_bytes = n_bytes & 0x3;
+
+ spin_lock(&inst->transaction_lock);
+ n_bytes -= odd_bytes;
+ if (n_bytes > DMA_THRESHOLD_BYTES) {
+ dma_addr_t phy_addr = dma_map_single(inst->dev,
+ buf, n_bytes,
+ DMA_DEV_TO_MEM);
+ struct scatterlist *sgl = smi_scatterlist_from_buffer(
+ inst, phy_addr, n_bytes,
+ &inst->buffer_sgl);
+ if (!sgl) {
+ smi_dump_context_labelled(inst,
+ "Error: could not create scatterlist for read!");
+ goto out;
+ }
+ smi_dma_read_sgl(inst, sgl, 1, n_bytes);
+ dma_unmap_single(inst->dev, phy_addr, n_bytes, DMA_DEV_TO_MEM);
+ } else if (n_bytes) {
+ smi_read_fifo(inst, (uint32_t *)buf, n_bytes);
+ }
+ buf += n_bytes;
+
+ if (inst->settings.data_width == SMI_WIDTH_8BIT) {
+ while (odd_bytes--)
+ *((uint8_t *) (buf++)) = smi_read_single_word(inst);
+ } else {
+ while (odd_bytes >= 2) {
+ *(uint16_t *) buf = smi_read_single_word(inst);
+ buf += 2;
+ odd_bytes -= 2;
+ }
+ if (odd_bytes) {
+ dev_err(inst->dev,
+ "WARNING: odd number of bytes specified for wide transfer.");
+ dev_err(inst->dev,
+ "At least one byte dropped as a result.");
+ dump_stack();
+ }
+ }
+out:
+ spin_unlock(&inst->transaction_lock);
+}
+EXPORT_SYMBOL(bcm2835_smi_read_buf);
+
+void bcm2835_smi_set_address(struct bcm2835_smi_instance *inst,
+ unsigned int address)
+{
+ spin_lock(&inst->transaction_lock);
+ smi_set_address(inst, address);
+ spin_unlock(&inst->transaction_lock);
+}
+EXPORT_SYMBOL(bcm2835_smi_set_address);
+
+struct bcm2835_smi_instance *bcm2835_smi_get(struct device_node *node)
+{
+ struct platform_device *pdev;
+
+ if (!node)
+ return NULL;
+
+ pdev = of_find_device_by_node(node);
+ if (!pdev)
+ return NULL;
+
+ return platform_get_drvdata(pdev);
+}
+EXPORT_SYMBOL(bcm2835_smi_get);
+
+/****************************************************************************
+*
+* bcm2835_smi_probe - called when the driver is loaded.
+*
+***************************************************************************/
+
+static int bcm2835_smi_dma_setup(struct bcm2835_smi_instance *inst)
+{
+ int i, rv = 0;
+
+ inst->dma_chan = dma_request_slave_channel(inst->dev, "rx-tx");
+
+ inst->dma_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ inst->dma_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ inst->dma_config.src_addr = inst->smi_regs_busaddr + SMID;
+ inst->dma_config.dst_addr = inst->dma_config.src_addr;
+ /* Direction unimportant - always overridden by prep_slave_sg */
+ inst->dma_config.direction = DMA_DEV_TO_MEM;
+ dmaengine_slave_config(inst->dma_chan, &inst->dma_config);
+ /* Alloc and map bounce buffers */
+ for (i = 0; i < DMA_BOUNCE_BUFFER_COUNT; ++i) {
+ inst->bounce.buffer[i] =
+ dmam_alloc_coherent(inst->dev, DMA_BOUNCE_BUFFER_SIZE,
+ &inst->bounce.phys[i],
+ GFP_KERNEL);
+ if (!inst->bounce.buffer[i]) {
+ dev_err(inst->dev, "Could not allocate buffer!");
+ rv = -ENOMEM;
+ break;
+ }
+ smi_scatterlist_from_buffer(
+ inst,
+ inst->bounce.phys[i],
+ DMA_BOUNCE_BUFFER_SIZE,
+ &inst->bounce.sgl[i]
+ );
+ }
+
+ return rv;
+}
+
+static int bcm2835_smi_probe(struct platform_device *pdev)
+{
+ int err;
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct resource *ioresource;
+ struct bcm2835_smi_instance *inst;
+
+ /* Allocate buffers and instance data */
+
+ inst = devm_kzalloc(dev, sizeof(struct bcm2835_smi_instance),
+ GFP_KERNEL);
+
+ if (!inst)
+ return -ENOMEM;
+
+ inst->dev = dev;
+ spin_lock_init(&inst->transaction_lock);
+
+ /* We require device tree support */
+ if (!node)
+ return -EINVAL;
+
+ ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ inst->smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
+ ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ inst->cm_smi_regs_ptr = devm_ioremap_resource(dev, ioresource);
+ inst->smi_regs_busaddr = be32_to_cpu(
+ *of_get_address(node, 0, NULL, NULL));
+ of_property_read_u32(node,
+ "brcm,smi-clock-source",
+ &inst->clock_source);
+ of_property_read_u32(node,
+ "brcm,smi-clock-divisor",
+ &inst->clock_divisor);
+
+ err = bcm2835_smi_dma_setup(inst);
+ if (err)
+ return err;
+
+ /* Finally, do peripheral setup */
+
+ smi_setup_clock(inst);
+ smi_setup_regs(inst);
+
+ platform_set_drvdata(pdev, inst);
+
+ dev_info(inst->dev, "initialised");
+
+ return 0;
+}
+
+/****************************************************************************
+*
+* bcm2835_smi_remove - called when the driver is unloaded.
+*
+***************************************************************************/
+
+static int bcm2835_smi_remove(struct platform_device *pdev)
+{
+ struct bcm2835_smi_instance *inst = platform_get_drvdata(pdev);
+ struct device *dev = inst->dev;
+
+ dev_info(dev, "SMI device removed - OK");
+ return 0;
+}
+
+/****************************************************************************
+*
+* Register the driver with device tree
+*
+***************************************************************************/
+
+static const struct of_device_id bcm2835_smi_of_match[] = {
+ {.compatible = "brcm,bcm2835-smi",},
+ { /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, bcm2835_smi_of_match);
+
+static struct platform_driver bcm2835_smi_driver = {
+ .probe = bcm2835_smi_probe,
+ .remove = bcm2835_smi_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = bcm2835_smi_of_match,
+ },
+};
+
+module_platform_driver(bcm2835_smi_driver);
+
+MODULE_ALIAS("platform:smi-bcm2835");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Device driver for BCM2835's secondary memory interface");
+MODULE_AUTHOR("Luke Wren <luke@raspberrypi.org>");
--- /dev/null
+++ b/include/linux/broadcom/bcm2835_smi.h
@@ -0,0 +1,391 @@
+/**
+ * Declarations and definitions for Broadcom's Secondary Memory Interface
+ *
+ * Written by Luke Wren <luke@raspberrypi.org>
+ * Copyright (c) 2015, Raspberry Pi (Trading) Ltd.
+ * Copyright (c) 2010-2012 Broadcom. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the above-listed copyright holders may not be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2, as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef BCM2835_SMI_H
+#define BCM2835_SMI_H
+
+#include <linux/ioctl.h>
+
+#ifndef __KERNEL__
+#include <stdint.h>
+#include <stdbool.h>
+#endif
+
+#define BCM2835_SMI_IOC_MAGIC 0x1
+#define BCM2835_SMI_INVALID_HANDLE (~0)
+
+/* IOCTLs 0x100...0x1ff are not device-specific - we can use them */
+#define BCM2835_SMI_IOC_GET_SETTINGS _IO(BCM2835_SMI_IOC_MAGIC, 0)
+#define BCM2835_SMI_IOC_WRITE_SETTINGS _IO(BCM2835_SMI_IOC_MAGIC, 1)
+#define BCM2835_SMI_IOC_ADDRESS _IO(BCM2835_SMI_IOC_MAGIC, 2)
+#define BCM2835_SMI_IOC_MAX 2
+
+#define SMI_WIDTH_8BIT 0
+#define SMI_WIDTH_16BIT 1
+#define SMI_WIDTH_9BIT 2
+#define SMI_WIDTH_18BIT 3
+
+/* max number of bytes where DMA will not be used */
+#define DMA_THRESHOLD_BYTES 128
+#define DMA_BOUNCE_BUFFER_SIZE (1024 * 1024 / 2)
+#define DMA_BOUNCE_BUFFER_COUNT 3
+
+
+struct smi_settings {
+ int data_width;
+ /* Whether or not to pack multiple SMI transfers into a
+ single 32 bit FIFO word */
+ bool pack_data;
+
+ /* Timing for reads (writes the same but for WE)
+ *
+ * OE ----------+ +--------------------
+ * | |
+ * +----------+
+ * SD -<==============================>-----------
+ * SA -<=========================================>-
+ * <-setup-> <-strobe -> <-hold -> <- pace ->
+ */
+
+ int read_setup_time;
+ int read_hold_time;
+ int read_pace_time;
+ int read_strobe_time;
+
+ int write_setup_time;
+ int write_hold_time;
+ int write_pace_time;
+ int write_strobe_time;
+
+ bool dma_enable; /* DREQs */
+ bool dma_passthrough_enable; /* External DREQs */
+ int dma_read_thresh;
+ int dma_write_thresh;
+ int dma_panic_read_thresh;
+ int dma_panic_write_thresh;
+};
+
+/****************************************************************************
+*
+* Declare exported SMI functions
+*
+***************************************************************************/
+
+#ifdef __KERNEL__
+
+#include <linux/dmaengine.h> /* for enum dma_transfer_direction */
+#include <linux/of.h>
+#include <linux/semaphore.h>
+
+struct bcm2835_smi_instance;
+
+struct bcm2835_smi_bounce_info {
+ struct semaphore callback_sem;
+ void *buffer[DMA_BOUNCE_BUFFER_COUNT];
+ dma_addr_t phys[DMA_BOUNCE_BUFFER_COUNT];
+ struct scatterlist sgl[DMA_BOUNCE_BUFFER_COUNT];
+};
+
+
+void bcm2835_smi_set_regs_from_settings(struct bcm2835_smi_instance *);
+
+struct smi_settings *bcm2835_smi_get_settings_from_regs(
+ struct bcm2835_smi_instance *inst);
+
+void bcm2835_smi_write_buf(
+ struct bcm2835_smi_instance *inst,
+ const void *buf,
+ size_t n_bytes);
+
+void bcm2835_smi_read_buf(
+ struct bcm2835_smi_instance *inst,
+ void *buf,
+ size_t n_bytes);
+
+void bcm2835_smi_set_address(struct bcm2835_smi_instance *inst,
+ unsigned int address);
+
+ssize_t bcm2835_smi_user_dma(
+ struct bcm2835_smi_instance *inst,
+ enum dma_transfer_direction dma_dir,
+ char __user *user_ptr,
+ size_t count,
+ struct bcm2835_smi_bounce_info **bounce);
+
+struct bcm2835_smi_instance *bcm2835_smi_get(struct device_node *node);
+
+#endif /* __KERNEL__ */
+
+/****************************************************************
+*
+* Implementation-only declarations
+*
+****************************************************************/
+
+#ifdef BCM2835_SMI_IMPLEMENTATION
+
+/* Clock manager registers for SMI clock: */
+#define CM_SMI_BASE_ADDRESS ((BCM2708_PERI_BASE) + 0x1010b0)
+/* Clock manager "password" to protect registers from spurious writes */
+#define CM_PWD (0x5a << 24)
+
+#define CM_SMI_CTL 0x00
+#define CM_SMI_DIV 0x04
+
+#define CM_SMI_CTL_FLIP (1 << 8)
+#define CM_SMI_CTL_BUSY (1 << 7)
+#define CM_SMI_CTL_KILL (1 << 5)
+#define CM_SMI_CTL_ENAB (1 << 4)
+#define CM_SMI_CTL_SRC_MASK (0xf)
+#define CM_SMI_CTL_SRC_OFFS (0)
+
+#define CM_SMI_DIV_DIVI_MASK (0xf << 12)
+#define CM_SMI_DIV_DIVI_OFFS (12)
+#define CM_SMI_DIV_DIVF_MASK (0xff << 4)
+#define CM_SMI_DIV_DIVF_OFFS (4)
+
+/* SMI register mapping:*/
+#define SMI_BASE_ADDRESS ((BCM2708_PERI_BASE) + 0x600000)
+
+#define SMICS 0x00 /* control + status register */
+#define SMIL 0x04 /* length/count (n external txfers) */
+#define SMIA 0x08 /* address register */
+#define SMID 0x0c /* data register */
+#define SMIDSR0 0x10 /* device 0 read settings */
+#define SMIDSW0 0x14 /* device 0 write settings */
+#define SMIDSR1 0x18 /* device 1 read settings */
+#define SMIDSW1 0x1c /* device 1 write settings */
+#define SMIDSR2 0x20 /* device 2 read settings */
+#define SMIDSW2 0x24 /* device 2 write settings */
+#define SMIDSR3 0x28 /* device 3 read settings */
+#define SMIDSW3 0x2c /* device 3 write settings */
+#define SMIDC 0x30 /* DMA control registers */
+#define SMIDCS 0x34 /* direct control/status register */
+#define SMIDA 0x38 /* direct address register */
+#define SMIDD 0x3c /* direct data registers */
+#define SMIFD 0x40 /* FIFO debug register */
+
+
+
+/* Control and Status register bits:
+ * SMICS_RXF : RX fifo full: 1 when RX fifo is full
+ * SMICS_TXE : TX fifo empty: 1 when empty.
+ * SMICS_RXD : RX fifo contains data: 1 when there is data.
+ * SMICS_TXD : TX fifo can accept data: 1 when true.
+ * SMICS_RXR : RX fifo needs reading: 1 when fifo more than 3/4 full, or
+ * when "DONE" and fifo not emptied.
+ * SMICS_TXW : TX fifo needs writing: 1 when less than 1/4 full.
+ * SMICS_AFERR : AXI FIFO error: 1 when fifo read when empty or written
+ * when full. Write 1 to clear.
+ * SMICS_EDREQ : 1 when external DREQ received.
+ * SMICS_PXLDAT : Pixel data: write 1 to enable pixel transfer modes.
+ * SMICS_SETERR : 1 if there was an error writing to setup regs (e.g.
+ * tx was in progress). Write 1 to clear.
+ * SMICS_PVMODE : Set to 1 to enable pixel valve mode.
+ * SMICS_INTR : Set to 1 to enable interrupt on RX.
+ * SMICS_INTT : Set to 1 to enable interrupt on TX.
+ * SMICS_INTD : Set to 1 to enable interrupt on DONE condition.
+ * SMICS_TEEN : Tear effect mode enabled: Programmed transfers will wait
+ * for a TE trigger before writing.
+ * SMICS_PAD1 : Padding settings for external transfers. For writes: the
+ * number of bytes initially written to the TX fifo that
+ * SMICS_PAD0 : should be ignored. For reads: the number of bytes that will
+ * be read before the data, and should be dropped.
+ * SMICS_WRITE : Transfer direction: 1 = write to external device, 0 = read
+ * SMICS_CLEAR : Write 1 to clear the FIFOs.
+ * SMICS_START : Write 1 to start the programmed transfer.
+ * SMICS_ACTIVE : Reads as 1 when a programmed transfer is underway.
+ * SMICS_DONE : Reads as 1 when transfer finished. For RX, not set until
+ * FIFO emptied.
+ * SMICS_ENABLE : Set to 1 to enable the SMI peripheral, 0 to disable.
+ */
+
+#define SMICS_RXF (1 << 31)
+#define SMICS_TXE (1 << 30)
+#define SMICS_RXD (1 << 29)
+#define SMICS_TXD (1 << 28)
+#define SMICS_RXR (1 << 27)
+#define SMICS_TXW (1 << 26)
+#define SMICS_AFERR (1 << 25)
+#define SMICS_EDREQ (1 << 15)
+#define SMICS_PXLDAT (1 << 14)
+#define SMICS_SETERR (1 << 13)
+#define SMICS_PVMODE (1 << 12)
+#define SMICS_INTR (1 << 11)
+#define SMICS_INTT (1 << 10)
+#define SMICS_INTD (1 << 9)
+#define SMICS_TEEN (1 << 8)
+#define SMICS_PAD1 (1 << 7)
+#define SMICS_PAD0 (1 << 6)
+#define SMICS_WRITE (1 << 5)
+#define SMICS_CLEAR (1 << 4)
+#define SMICS_START (1 << 3)
+#define SMICS_ACTIVE (1 << 2)
+#define SMICS_DONE (1 << 1)
+#define SMICS_ENABLE (1 << 0)
+
+/* Address register bits: */
+
+#define SMIA_DEVICE_MASK ((1 << 9) | (1 << 8))
+#define SMIA_DEVICE_OFFS (8)
+#define SMIA_ADDR_MASK (0x3f) /* bits 5 -> 0 */
+#define SMIA_ADDR_OFFS (0)
+
+/* DMA control register bits:
+ * SMIDC_DMAEN : DMA enable: set 1: DMA requests will be issued.
+ * SMIDC_DMAP : DMA passthrough: when set to 0, top two data pins are used by
+ * SMI as usual. When set to 1, the top two pins are used for
+ * external DREQs: pin 16 read request, 17 write.
+ * SMIDC_PANIC* : Threshold at which DMA will panic during read/write.
+ * SMIDC_REQ* : Threshold at which DMA will generate a DREQ.
+ */
+
+#define SMIDC_DMAEN (1 << 28)
+#define SMIDC_DMAP (1 << 24)
+#define SMIDC_PANICR_MASK (0x3f << 18)
+#define SMIDC_PANICR_OFFS (18)
+#define SMIDC_PANICW_MASK (0x3f << 12)
+#define SMIDC_PANICW_OFFS (12)
+#define SMIDC_REQR_MASK (0x3f << 6)
+#define SMIDC_REQR_OFFS (6)
+#define SMIDC_REQW_MASK (0x3f)
+#define SMIDC_REQW_OFFS (0)
+
+/* Device settings register bits: same for all 4 (or 3?) device register sets.
+ * Device read settings:
+ * SMIDSR_RWIDTH : Read transfer width. 00 = 8bit, 01 = 16bit,
+ * 10 = 18bit, 11 = 9bit.
+ * SMIDSR_RSETUP : Read setup time: number of core cycles between chip
+ * select/address and read strobe. Min 1, max 64.
+ * SMIDSR_MODE68 : 1 for System 68 mode (i.e. enable + direction pins,
+ * rather than OE + WE pin)
+ * SMIDSR_FSETUP : If set to 1, setup time only applies to first
+ * transfer after address change.
+ * SMIDSR_RHOLD : Number of core cycles between read strobe going
+ * inactive and CS/address going inactive. Min 1, max 64
+ * SMIDSR_RPACEALL : When set to 1, this device's RPACE value will always
+ * be used for the next transaction, even if it is not
+ * to this device.
+ * SMIDSR_RPACE : Number of core cycles spent waiting between CS
+ * deassert and start of next transfer. Min 1, max 128
+ * SMIDSR_RDREQ : 1 = use external DMA request on SD16 to pace reads
+ * from device. Must also set DMAP in SMICS.
+ * SMIDSR_RSTROBE : Number of cycles to assert the read strobe.
+ * min 1, max 128.
+ */
+#define SMIDSR_RWIDTH_MASK ((1<<31)|(1<<30))
+#define SMIDSR_RWIDTH_OFFS (30)
+#define SMIDSR_RSETUP_MASK (0x3f << 24)
+#define SMIDSR_RSETUP_OFFS (24)
+#define SMIDSR_MODE68 (1 << 23)
+#define SMIDSR_FSETUP (1 << 22)
+#define SMIDSR_RHOLD_MASK (0x3f << 16)
+#define SMIDSR_RHOLD_OFFS (16)
+#define SMIDSR_RPACEALL (1 << 15)
+#define SMIDSR_RPACE_MASK (0x7f << 8)
+#define SMIDSR_RPACE_OFFS (8)
+#define SMIDSR_RDREQ (1 << 7)
+#define SMIDSR_RSTROBE_MASK (0x7f)
+#define SMIDSR_RSTROBE_OFFS (0)
+
+/* Device write settings:
+ * SMIDSW_WWIDTH : Write transfer width. 00 = 8bit, 01 = 16bit,
+ * 10= 18bit, 11 = 9bit.
+ * SMIDSW_WSETUP : Number of cycles between CS assert and write strobe.
+ * Min 1, max 64.
+ * SMIDSW_WFORMAT : Pixel format of input. 0 = 16bit RGB 565,
+ * 1 = 32bit RGBA 8888
+ * SMIDSW_WSWAP : 1 = swap pixel data bits. (Use with SMICS_PXLDAT)
+ * SMIDSW_WHOLD : Time between WE deassert and CS deassert. 1 to 64
+ * SMIDSW_WPACEALL : 1: this device's WPACE will be used for the next
+ * transfer, regardless of that transfer's device.
+ * SMIDSW_WPACE : Cycles between CS deassert and next CS assert.
+ * Min 1, max 128
+ * SMIDSW_WDREQ : Use external DREQ on pin 17 to pace writes. DMAP must
+ * be set in SMICS.
+ * SMIDSW_WSTROBE : Number of cycles to assert the write strobe.
+ * Min 1, max 128
+ */
+#define SMIDSW_WWIDTH_MASK ((1<<31)|(1<<30))
+#define SMIDSW_WWIDTH_OFFS (30)
+#define SMIDSW_WSETUP_MASK (0x3f << 24)
+#define SMIDSW_WSETUP_OFFS (24)
+#define SMIDSW_WFORMAT (1 << 23)
+#define SMIDSW_WSWAP (1 << 22)
+#define SMIDSW_WHOLD_MASK (0x3f << 16)
+#define SMIDSW_WHOLD_OFFS (16)
+#define SMIDSW_WPACEALL (1 << 15)
+#define SMIDSW_WPACE_MASK (0x7f << 8)
+#define SMIDSW_WPACE_OFFS (8)
+#define SMIDSW_WDREQ (1 << 7)
+#define SMIDSW_WSTROBE_MASK (0x7f)
+#define SMIDSW_WSTROBE_OFFS (0)
+
+/* Direct transfer control + status register
+ * SMIDCS_WRITE : Direction of transfer: 1 -> write, 0 -> read
+ * SMIDCS_DONE : 1 when a transfer has finished. Write 1 to clear.
+ * SMIDCS_START : Write 1 to start a transfer, if one is not already underway.
+ * SMIDCE_ENABLE: Write 1 to enable SMI in direct mode.
+ */
+
+#define SMIDCS_WRITE (1 << 3)
+#define SMIDCS_DONE (1 << 2)
+#define SMIDCS_START (1 << 1)
+#define SMIDCS_ENABLE (1 << 0)
+
+/* Direct transfer address register
+ * SMIDA_DEVICE : Indicates which of the device settings banks should be used.
+ * SMIDA_ADDR : The value to be asserted on the address pins.
+ */
+
+#define SMIDA_DEVICE_MASK ((1<<9)|(1<<8))
+#define SMIDA_DEVICE_OFFS (8)
+#define SMIDA_ADDR_MASK (0x3f)
+#define SMIDA_ADDR_OFFS (0)
+
+/* FIFO debug register
+ * SMIFD_FLVL : The high-tide mark of FIFO count during the most recent txfer
+ * SMIFD_FCNT : The current FIFO count.
+ */
+#define SMIFD_FLVL_MASK (0x3f << 8)
+#define SMIFD_FLVL_OFFS (8)
+#define SMIFD_FCNT_MASK (0x3f)
+#define SMIFD_FCNT_OFFS (0)
+
+#endif /* BCM2835_SMI_IMPLEMENTATION */
+
+#endif /* BCM2835_SMI_H */
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