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ramips: add clock strecthing support to i2c driver

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fixes #19816

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

SVN-Revision: 46472
This commit is contained in:
John Crispin 2015-07-24 09:11:42 +00:00
parent e7b34b2b0d
commit 7449ea88db
1 changed files with 35 additions and 32 deletions
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61
target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch
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@ -45,7 +45,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+};
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -710,6 +710,10 @@ config I2C_RK3X
@@ -710,6 +710,10 @@
This driver can also be built as a module. If so, the module will
be called i2c-rk3x.
@ -58,7 +58,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
help
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
@@ -66,6 +66,7 @@
obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o
obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o
@ -68,7 +68,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ralink.c
@@ -0,0 +1,299 @@
@@ -0,0 +1,302 @@
+/*
+ * drivers/i2c/busses/i2c-ralink.c
+ *
@ -122,8 +122,6 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+#define I2C_DEVADLEN_7 (6 << 2)
+#define I2C_ADDRDIS BIT(1)
+
+#define I2C_RETRY 0x1000
+
+#define CLKDIV_VALUE 200 // clock rate is 40M, 40M / (200*2) = 100k (standard i2c bus rate).
+//#define CLKDIV_VALUE 50 // clock rate is 40M, 40M / (50*2) = 400k (fast i2c bus rate).
+
@ -131,6 +129,9 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+#define WRITE_CMD 0x00
+#define READ_BLOCK 64
+
+/* timeout waiting for I2C devices to respond (clock streching) */
+#define RT_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+static void __iomem *membase;
+static struct i2c_adapter *adapter;
+
@ -151,38 +152,48 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+
+static inline int rt_i2c_wait_rx_done(void)
+{
+ int retries = I2C_RETRY;
+ unsigned long timeout;
+
+ timeout = jiffies + RT_I2C_TIMEOUT;
+
+ do {
+ if (!retries--)
+ break;
+ if (time_after(jiffies, timeout))
+ return (-ETIMEDOUT);
+
+ } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
+
+ return (retries < 0) ? -ETIMEDOUT : 0;
+ return 0;
+}
+
+static inline int rt_i2c_wait_idle(void)
+{
+ int retries = I2C_RETRY;
+ unsigned long timeout;
+
+ timeout = jiffies + RT_I2C_TIMEOUT;
+
+ do {
+ if (!retries--)
+ break;
+ if (time_after(jiffies, timeout)) {
+ printk("i2c-read line busy\n");
+ return 1;
+ }
+ } while (rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
+
+ return (retries < 0);
+ return 0;
+}
+
+static inline int rt_i2c_wait_tx_done(void)
+{
+ int retries = I2C_RETRY;
+ unsigned long timeout;
+
+ timeout = jiffies + RT_I2C_TIMEOUT;
+
+ do {
+ if (!retries--)
+ break;
+ if (time_after(jiffies, timeout))
+ return (-ETIMEDOUT);
+
+ } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
+
+ return (retries < 0) ? -ETIMEDOUT : 0;
+ return 0;
+}
+
+static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
@ -199,10 +210,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+
+ if (msg->flags & I2C_M_RD) {
+ for (i = 0; i < nblock; i++) {
+ if (rt_i2c_wait_idle()) {
+ printk("i2c-read line busy\n");
+ if (rt_i2c_wait_idle())
+ return -ETIMEDOUT;
+ }
+ rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
+ rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
+ for (j = 0; j < READ_BLOCK; j++) {
@ -214,10 +223,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ }
+ }
+
+ if (rt_i2c_wait_idle()) {
+ printk("i2c-read line busy\n");
+ if (rt_i2c_wait_idle())
+ return -ETIMEDOUT;
+ }
+ if (rem) {
+ rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
+ rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
@ -231,10 +238,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
+ }
+ } else {
+ if (rt_i2c_wait_idle()) {
+ printk("i2c-write line busy\n");
+ if (rt_i2c_wait_idle())
+ return -ETIMEDOUT;
+ }
+ rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
+ for (i = 0; i < msg->len; i++) {
+ rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
@ -255,10 +260,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ int i = 0;
+ int ret = 0;
+
+ if (rt_i2c_wait_idle()) {
+ printk("i2c-master_xfer line busy\n");
+ if (rt_i2c_wait_idle())
+ return -ETIMEDOUT;
+ }
+
+ device_reset(a->dev.parent);
+