summaryrefslogtreecommitdiff
path: root/drivers/i2c/busses/i2c-davinci.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/busses/i2c-davinci.c')
-rw-r--r--drivers/i2c/busses/i2c-davinci.c194
1 files changed, 143 insertions, 51 deletions
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 6dc7ff5d3d9a..4788a32afb86 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -60,6 +60,12 @@
#define DAVINCI_I2C_IVR_REG 0x28
#define DAVINCI_I2C_EMDR_REG 0x2c
#define DAVINCI_I2C_PSC_REG 0x30
+#define DAVINCI_I2C_FUNC_REG 0x48
+#define DAVINCI_I2C_DIR_REG 0x4c
+#define DAVINCI_I2C_DIN_REG 0x50
+#define DAVINCI_I2C_DOUT_REG 0x54
+#define DAVINCI_I2C_DSET_REG 0x58
+#define DAVINCI_I2C_DCLR_REG 0x5c
#define DAVINCI_I2C_IVR_AAS 0x07
#define DAVINCI_I2C_IVR_SCD 0x06
@@ -93,6 +99,29 @@
#define DAVINCI_I2C_IMR_NACK BIT(1)
#define DAVINCI_I2C_IMR_AL BIT(0)
+/* set SDA and SCL as GPIO */
+#define DAVINCI_I2C_FUNC_PFUNC0 BIT(0)
+
+/* set SCL as output when used as GPIO*/
+#define DAVINCI_I2C_DIR_PDIR0 BIT(0)
+/* set SDA as output when used as GPIO*/
+#define DAVINCI_I2C_DIR_PDIR1 BIT(1)
+
+/* read SCL GPIO level */
+#define DAVINCI_I2C_DIN_PDIN0 BIT(0)
+/* read SDA GPIO level */
+#define DAVINCI_I2C_DIN_PDIN1 BIT(1)
+
+/*set the SCL GPIO high */
+#define DAVINCI_I2C_DSET_PDSET0 BIT(0)
+/*set the SDA GPIO high */
+#define DAVINCI_I2C_DSET_PDSET1 BIT(1)
+
+/* set the SCL GPIO low */
+#define DAVINCI_I2C_DCLR_PDCLR0 BIT(0)
+/* set the SDA GPIO low */
+#define DAVINCI_I2C_DCLR_PDCLR1 BIT(1)
+
struct davinci_i2c_dev {
struct device *dev;
void __iomem *base;
@@ -129,43 +158,6 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
return readw_relaxed(i2c_dev->base + reg);
}
-/* Generate a pulse on the i2c clock pin. */
-static void davinci_i2c_clock_pulse(unsigned int scl_pin)
-{
- u16 i;
-
- if (scl_pin) {
- /* Send high and low on the SCL line */
- for (i = 0; i < 9; i++) {
- gpio_set_value(scl_pin, 0);
- udelay(20);
- gpio_set_value(scl_pin, 1);
- udelay(20);
- }
- }
-}
-
-/* This routine does i2c bus recovery as specified in the
- * i2c protocol Rev. 03 section 3.16 titled "Bus clear"
- */
-static void davinci_i2c_recover_bus(struct davinci_i2c_dev *dev)
-{
- u32 flag = 0;
- struct davinci_i2c_platform_data *pdata = dev->pdata;
-
- dev_err(dev->dev, "initiating i2c bus recovery\n");
- /* Send NACK to the slave */
- flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- flag |= DAVINCI_I2C_MDR_NACK;
- /* write the data into mode register */
- davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
- davinci_i2c_clock_pulse(pdata->scl_pin);
- /* Send STOP */
- flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- flag |= DAVINCI_I2C_MDR_STP;
- davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
-}
-
static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
int val)
{
@@ -263,6 +255,99 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
}
/*
+ * This routine does i2c bus recovery by using i2c_generic_gpio_recovery
+ * which is provided by I2C Bus recovery infrastructure.
+ */
+static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+ /* Disable interrupts */
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0);
+
+ /* put I2C into reset */
+ davinci_i2c_reset_ctrl(dev, 0);
+}
+
+static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+ i2c_davinci_init(dev);
+}
+
+static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = {
+ .recover_bus = i2c_generic_gpio_recovery,
+ .prepare_recovery = davinci_i2c_prepare_recovery,
+ .unprepare_recovery = davinci_i2c_unprepare_recovery,
+};
+
+static void davinci_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+ if (val)
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_DSET_REG,
+ DAVINCI_I2C_DSET_PDSET0);
+ else
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_DCLR_REG,
+ DAVINCI_I2C_DCLR_PDCLR0);
+}
+
+static int davinci_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+ int val;
+
+ /* read the state of SCL */
+ val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
+ return val & DAVINCI_I2C_DIN_PDIN0;
+}
+
+static int davinci_i2c_get_sda(struct i2c_adapter *adap)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+ int val;
+
+ /* read the state of SDA */
+ val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
+ return val & DAVINCI_I2C_DIN_PDIN1;
+}
+
+static void davinci_i2c_scl_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+ davinci_i2c_prepare_recovery(adap);
+
+ /* SCL output, SDA input */
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_DIR_REG, DAVINCI_I2C_DIR_PDIR0);
+
+ /* change to GPIO mode */
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG,
+ DAVINCI_I2C_FUNC_PFUNC0);
+}
+
+static void davinci_i2c_scl_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+ /* change back to I2C mode */
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 0);
+
+ davinci_i2c_unprepare_recovery(adap);
+}
+
+static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
+ .recover_bus = i2c_generic_scl_recovery,
+ .set_scl = davinci_i2c_set_scl,
+ .get_scl = davinci_i2c_get_scl,
+ .get_sda = davinci_i2c_get_sda,
+ .prepare_recovery = davinci_i2c_scl_prepare_recovery,
+ .unprepare_recovery = davinci_i2c_scl_unprepare_recovery,
+};
+
+/*
* Waiting for bus not busy
*/
static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
@@ -282,8 +367,7 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
return -ETIMEDOUT;
} else {
to_cnt = 0;
- davinci_i2c_recover_bus(dev);
- i2c_davinci_init(dev);
+ i2c_recover_bus(&dev->adapter);
}
}
if (allow_sleep)
@@ -304,7 +388,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
struct davinci_i2c_platform_data *pdata = dev->pdata;
u32 flag;
u16 w;
- int r;
+ unsigned long time_left;
/* Introduce a delay, required for some boards (e.g Davinci EVM) */
if (pdata->bus_delay)
@@ -368,11 +452,11 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
flag |= DAVINCI_I2C_MDR_STP;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
- r = wait_for_completion_timeout(&dev->cmd_complete, dev->adapter.timeout);
- if (r == 0) {
+ time_left = wait_for_completion_timeout(&dev->cmd_complete,
+ dev->adapter.timeout);
+ if (!time_left) {
dev_err(dev->dev, "controller timed out\n");
- davinci_i2c_recover_bus(dev);
- i2c_davinci_init(dev);
+ i2c_recover_bus(adap);
dev->buf_len = 0;
return -ETIMEDOUT;
}
@@ -380,17 +464,13 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
/* This should be 0 if all bytes were transferred
* or dev->cmd_err denotes an error.
*/
- if (r >= 0) {
- dev_err(dev->dev, "abnormal termination buf_len=%i\n",
- dev->buf_len);
- r = -EREMOTEIO;
- }
+ dev_err(dev->dev, "abnormal termination buf_len=%i\n",
+ dev->buf_len);
dev->terminate = 1;
wmb();
dev->buf_len = 0;
+ return -EREMOTEIO;
}
- if (r < 0)
- return r;
/* no error */
if (likely(!dev->cmd_err))
@@ -674,6 +754,10 @@ static int davinci_i2c_probe(struct platform_device *pdev)
if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
&prop))
dev->pdata->bus_freq = prop / 1000;
+
+ dev->pdata->has_pfunc =
+ of_property_read_bool(pdev->dev.of_node,
+ "ti,has-pfunc");
} else if (!dev->pdata) {
dev->pdata = &davinci_i2c_platform_data_default;
}
@@ -715,6 +799,14 @@ static int davinci_i2c_probe(struct platform_device *pdev)
adap->timeout = DAVINCI_I2C_TIMEOUT;
adap->dev.of_node = pdev->dev.of_node;
+ if (dev->pdata->has_pfunc)
+ adap->bus_recovery_info = &davinci_i2c_scl_recovery_info;
+ else if (dev->pdata->scl_pin) {
+ adap->bus_recovery_info = &davinci_i2c_gpio_recovery_info;
+ adap->bus_recovery_info->scl_gpio = dev->pdata->scl_pin;
+ adap->bus_recovery_info->sda_gpio = dev->pdata->sda_pin;
+ }
+
adap->nr = pdev->id;
r = i2c_add_numbered_adapter(adap);
if (r) {