From: Troy Kisky <[EMAIL PROTECTED](none)>
ARM: DaVinci: i2c fix lost interrupt
DAVINCI_I2C_STR_REG is a write 1 to clear register,
so don't use a read/modify/write cycle.
EVM doesn't have platform data yet, make bus_delay default correct
Ensure psc value gives a clock between 7-12 Mhz
Make sure no interrupts are pending before starting transfer
Signed-off-by: Troy Kisky <[EMAIL PROTECTED]>
Acked-by: Kevin Hilman <[EMAIL PROTECTED]>
---
drivers/i2c/busses/i2c-davinci.c | 38 ++++++++++++++++++--------------------
1 files changed, 18 insertions(+), 20 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index f348ee0..488bd7c 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -123,7 +123,7 @@ struct davinci_i2c_dev {
/* default platform data to use if not supplied in the platform_device */
static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
.bus_freq = 100,
- .bus_delay = 0,
+ .bus_delay = 100,
};
static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
@@ -147,6 +147,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
u16 psc;
u32 clk;
+ u32 d;
u32 clkh;
u32 clkl;
u32 input_clock = clk_get_rate(dev->clk);
@@ -176,23 +177,26 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
* if PSC > 1 , d = 5
*/
- psc = 26; /* To get 1MHz clock */
+ psc = (input_clock/7000000)-1; /* To get minimum of
7 MHz clock */
+ if ( (input_clock/(psc+1)) > 12000000) psc++; /* maximum of 12Mhz */
+ d = (psc>=2)? 5 : 7 - psc;
- clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - 10;
- clkh = (50 * clk) / 100;
+ clk = ((input_clock/(psc+1)) / (pdata->bus_freq * 1000)) - (d<<1);
+ clkh = clk>>1;
clkl = clk - clkh;
davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
- dev_dbg(dev->dev, "CLK = %d\n", clk);
+ dev_dbg(dev->dev, "input_clock=%d, CLK = %d\n", input_clock,clk);
dev_dbg(dev->dev, "PSC = %d\n",
davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
dev_dbg(dev->dev, "CLKL = %d\n",
davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
dev_dbg(dev->dev, "CLKH = %d\n",
davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
+ dev_dbg(dev->dev, "bus_freq = %dKHz bus_delay =
%d\n",pdata->bus_freq,pdata->bus_delay);
/* Take the I2C module out of reset: */
w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
@@ -278,7 +282,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct
i2c_msg *msg, int stop)
dev->cmd_err = 0;
/* Clear any pending interrupts by reading the IVR */
- stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG);
+ do {
+ stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG);
+ } while (stat);
/* Take I2C out of reset, configure it as master and set the
* start bit */
@@ -358,12 +364,10 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg
msgs[], int num)
for (i = 0; i < num; i++) {
ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+ dev_dbg(dev->dev, "%s ret: %d\n", __FUNCTION__, ret);
if (ret < 0)
return ret;
}
-
- dev_dbg(dev->dev, "%s:%d ret: %d\n", __FUNCTION__, __LINE__, ret);
-
return num;
}
@@ -406,9 +410,8 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void
*dev_id)
break;
case DAVINCI_I2C_IVR_ARDY:
- w = davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_STR_ARDY, 1);
- davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, w);
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
complete(&dev->cmd_complete);
break;
@@ -421,12 +424,8 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void
*dev_id)
if (dev->buf_len)
continue;
- w = davinci_i2c_read_reg(dev,
- DAVINCI_I2C_STR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_IMR_RRDY, 0);
davinci_i2c_write_reg(dev,
- DAVINCI_I2C_STR_REG,
- w);
+
DAVINCI_I2C_STR_REG,DAVINCI_I2C_IMR_RRDY);
} else
dev_err(dev->dev, "RDR IRQ while no "
"data requested\n");
@@ -452,9 +451,8 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void
*dev_id)
break;
case DAVINCI_I2C_IVR_SCD:
- w = davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_STR_SCD, 1);
- davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, w);
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
complete(&dev->cmd_complete);
break;
--
1.5.4
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