From 7449ea88db715d5c3da9e1a45968ea1ee7459e73 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Fri, 24 Jul 2015 09:11:42 +0000 Subject: [PATCH] ramips: add clock strecthing support to i2c driver fixes #19816 Signed-off-by: John Crispin SVN-Revision: 46472 --- ...0052-i2c-MIPS-adds-ralink-I2C-driver.patch | 67 ++++++++++--------- 1 file changed, 35 insertions(+), 32 deletions(-) diff --git a/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch b/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch index 9b7fba841082..9c2538879c6b 100644 --- a/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch +++ b/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch @@ -45,7 +45,7 @@ Signed-off-by: John Crispin +}; --- 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 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 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 +#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 +#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 + +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; -+ } while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY)); ++ if (time_after(jiffies, timeout)) ++ return (-ETIMEDOUT); + -+ return (retries < 0) ? -ETIMEDOUT : 0; ++ } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY)); ++ ++ 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; -+ } while(rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY); ++ 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; -+ } while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY)); ++ 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 + + 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 + } + } + -+ 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 + 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 + 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); + -- 2.30.2