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openwrtv4/target/linux/mediatek/patches/0028-pwm-add-Mediatek-display-PWM-driver-support.patch
John Crispin 25afe99b31 mediatek: add support for the new MT7623 Arm SoC 
the support is still WIP. next steps are to make the pmic and ethernet work.
this is the first commit to make sure nothing gets lost.

Signed-off-by: John Crispin <blogic@openwrt.org>

SVN-Revision: 47354
2015-11-02 10:18:50 +00:00

281 lines
8.1 KiB
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From 77e664940f6daa86965d16a2047188519341a31a Mon Sep 17 00:00:00 2001
From: YH Huang <yh.huang@mediatek.com>
Date: Mon, 11 May 2015 17:26:22 +0800
Subject: [PATCH 28/76] pwm: add Mediatek display PWM driver support
Add display PWM driver support to modify backlight for MT8173/MT6595.
Signed-off-by: YH Huang <yh.huang@mediatek.com>
---
drivers/pwm/Kconfig | 9 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-disp-mediatek.c | 225 +++++++++++++++++++++++++++++++++++++++
3 files changed, 235 insertions(+)
create mode 100644 drivers/pwm/pwm-disp-mediatek.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index b1541f4..9edbb5a 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -111,6 +111,15 @@ config PWM_CLPS711X
To compile this driver as a module, choose M here: the module
will be called pwm-clps711x.
+config PWM_DISP_MEDIATEK
+ tristate "MEDIATEK display PWM driver"
+ depends on OF
+ help
+ Generic PWM framework driver for mediatek disp-pwm device.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-disp-mediatek.
+
config PWM_EP93XX
tristate "Cirrus Logic EP93xx PWM support"
depends on ARCH_EP93XX
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index ec50eb5..c5ff72a 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-kona.o
obj-$(CONFIG_PWM_BCM2835) += pwm-bcm2835.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o
+obj-$(CONFIG_PWM_DISP_MEDIATEK) += pwm-disp-mediatek.o
obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o
obj-$(CONFIG_PWM_IMG) += pwm-img.o
diff --git a/drivers/pwm/pwm-disp-mediatek.c b/drivers/pwm/pwm-disp-mediatek.c
new file mode 100644
index 0000000..38293af
--- /dev/null
+++ b/drivers/pwm/pwm-disp-mediatek.c
@@ -0,0 +1,225 @@
+/*
+ * Mediatek display pulse-width-modulation controller driver.
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author: YH Huang <yh.huang@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pwm.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define DISP_PWM_EN_OFF (0x0)
+#define PWM_ENABLE_SHIFT (0x0)
+#define PWM_ENABLE_MASK (0x1 << PWM_ENABLE_SHIFT)
+
+#define DISP_PWM_COMMIT_OFF (0x08)
+#define PWM_COMMIT_SHIFT (0x0)
+#define PWM_COMMIT_MASK (0x1 << PWM_COMMIT_SHIFT)
+
+#define DISP_PWM_CON_0_OFF (0x10)
+#define PWM_CLKDIV_SHIFT (0x10)
+#define PWM_CLKDIV_MASK (0x3ff << PWM_CLKDIV_SHIFT)
+#define PWM_CLKDIV_MAX (0x000003ff)
+
+#define DISP_PWM_CON_1_OFF (0x14)
+#define PWM_PERIOD_SHIFT (0x0)
+#define PWM_PERIOD_MASK (0xfff << PWM_PERIOD_SHIFT)
+#define PWM_PERIOD_MAX (0x00000fff)
+/* Shift log2(PWM_PERIOD_MAX + 1) as divisor */
+#define PWM_PERIOD_BIT_SHIFT 12
+
+#define PWM_HIGH_WIDTH_SHIFT (0x10)
+#define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT)
+
+#define NUM_PWM 1
+
+struct mtk_disp_pwm_chip {
+ struct pwm_chip chip;
+ struct device *dev;
+ struct clk *clk_main;
+ struct clk *clk_mm;
+ void __iomem *mmio_base;
+};
+
+static void mtk_disp_pwm_setting(void __iomem *address, u32 value, u32 mask)
+{
+ u32 val;
+
+ val = readl(address);
+ val &= ~mask;
+ val |= value;
+ writel(val, address);
+}
+
+static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct mtk_disp_pwm_chip *mpc;
+ u64 div, rate;
+ u32 clk_div, period, high_width, rem;
+
+ /*
+ * Find period, high_width and clk_div to suit duty_ns and period_ns.
+ * Calculate proper div value to keep period value in the bound.
+ *
+ * period_ns = 10^9 * (clk_div + 1) * (period +1) / PWM_CLK_RATE
+ * duty_ns = 10^9 * (clk_div + 1) * (high_width + 1) / PWM_CLK_RATE
+ *
+ * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1
+ * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1)) - 1
+ */
+ mpc = container_of(chip, struct mtk_disp_pwm_chip, chip);
+ rate = clk_get_rate(mpc->clk_main);
+ clk_div = div_u64_rem(rate * period_ns, NSEC_PER_SEC, &rem) >>
+ PWM_PERIOD_BIT_SHIFT;
+ if (clk_div > PWM_CLKDIV_MAX)
+ return -EINVAL;
+
+ div = clk_div + 1;
+ period = div64_u64(rate * period_ns, NSEC_PER_SEC * div);
+ if (period > 0)
+ period--;
+ high_width = div64_u64(rate * duty_ns, NSEC_PER_SEC * div);
+ if (high_width > 0)
+ high_width--;
+
+ mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_CON_0_OFF,
+ clk_div << PWM_CLKDIV_SHIFT, PWM_CLKDIV_MASK);
+ mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_CON_1_OFF,
+ (period << PWM_PERIOD_SHIFT) |
+ (high_width << PWM_HIGH_WIDTH_SHIFT),
+ PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK);
+
+ mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_COMMIT_OFF,
+ 1 << PWM_COMMIT_SHIFT, PWM_COMMIT_MASK);
+ mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_COMMIT_OFF,
+ 0 << PWM_COMMIT_SHIFT, PWM_COMMIT_MASK);
+
+ return 0;
+}
+
+static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mtk_disp_pwm_chip *mpc;
+
+ mpc = container_of(chip, struct mtk_disp_pwm_chip, chip);
+ mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_EN_OFF,
+ 1 << PWM_ENABLE_SHIFT, PWM_ENABLE_MASK);
+
+ return 0;
+}
+
+static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mtk_disp_pwm_chip *mpc;
+
+ mpc = container_of(chip, struct mtk_disp_pwm_chip, chip);
+ mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_EN_OFF,
+ 0 << PWM_ENABLE_SHIFT, PWM_ENABLE_MASK);
+}
+
+static const struct pwm_ops mtk_disp_pwm_ops = {
+ .config = mtk_disp_pwm_config,
+ .enable = mtk_disp_pwm_enable,
+ .disable = mtk_disp_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int mtk_disp_pwm_probe(struct platform_device *pdev)
+{
+ struct mtk_disp_pwm_chip *pwm;
+ struct resource *r;
+ int ret;
+
+ pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+ if (!pwm)
+ return -ENOMEM;
+
+ pwm->dev = &pdev->dev;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(pwm->mmio_base))
+ return PTR_ERR(pwm->mmio_base);
+
+ pwm->clk_main = devm_clk_get(&pdev->dev, "main");
+ if (IS_ERR(pwm->clk_main))
+ return PTR_ERR(pwm->clk_main);
+ pwm->clk_mm = devm_clk_get(&pdev->dev, "mm");
+ if (IS_ERR(pwm->clk_mm))
+ return PTR_ERR(pwm->clk_mm);
+
+ ret = clk_prepare_enable(pwm->clk_main);
+ if (ret < 0)
+ return ret;
+ ret = clk_prepare_enable(pwm->clk_mm);
+ if (ret < 0) {
+ clk_disable_unprepare(pwm->clk_main);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, pwm);
+
+ pwm->chip.dev = &pdev->dev;
+ pwm->chip.ops = &mtk_disp_pwm_ops;
+ pwm->chip.base = -1;
+ pwm->chip.npwm = NUM_PWM;
+
+ ret = pwmchip_add(&pwm->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int mtk_disp_pwm_remove(struct platform_device *pdev)
+{
+ struct mtk_disp_pwm_chip *pc = platform_get_drvdata(pdev);
+
+ if (WARN_ON(!pc))
+ return -ENODEV;
+
+ clk_disable_unprepare(pc->clk_main);
+ clk_disable_unprepare(pc->clk_mm);
+
+ return pwmchip_remove(&pc->chip);
+}
+
+static const struct of_device_id mtk_disp_pwm_of_match[] = {
+ { .compatible = "mediatek,mt6595-disp-pwm" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
+
+static struct platform_driver mtk_disp_pwm_driver = {
+ .driver = {
+ .name = "mediatek-disp-pwm",
+ .owner = THIS_MODULE,
+ .of_match_table = mtk_disp_pwm_of_match,
+ },
+ .probe = mtk_disp_pwm_probe,
+ .remove = mtk_disp_pwm_remove,
+};
+
+module_platform_driver(mtk_disp_pwm_driver);
+
+MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>");
+MODULE_DESCRIPTION("MediaTek SoC display PWM driver");
+MODULE_LICENSE("GPL v2");
--
1.7.10.4
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