diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-davinci.txt | 3 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-davinci.c | 102 | ||||
| -rw-r--r-- | include/linux/platform_data/i2c-davinci.h | 1 |
3 files changed, 105 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-davinci.txt b/Documentation/devicetree/bindings/i2c/i2c-davinci.txt index 2dc935b4113d..a4e1cbc810c1 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-davinci.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-davinci.txt @@ -10,6 +10,9 @@ Required properties: Recommended properties : - interrupts : standard interrupt property. - clock-frequency : desired I2C bus clock frequency in Hz. +- ti,has-pfunc: boolean; if defined, it indicates that SoC supports PFUNC + registers. PFUNC registers allow to switch I2C pins to function as + GPIOs, so they can by toggled manually. Example (enbw_cmc board): i2c@1c22000 { diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 54819fb4f82e..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; @@ -253,6 +282,71 @@ static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = { .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 */ @@ -660,6 +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; } @@ -701,7 +799,9 @@ 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->scl_pin) { + 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; diff --git a/include/linux/platform_data/i2c-davinci.h b/include/linux/platform_data/i2c-davinci.h index 2312d197dfb7..89fd34727a24 100644 --- a/include/linux/platform_data/i2c-davinci.h +++ b/include/linux/platform_data/i2c-davinci.h @@ -18,6 +18,7 @@ struct davinci_i2c_platform_data { unsigned int bus_delay; /* post-transaction delay (usec) */ unsigned int sda_pin; /* GPIO pin ID to use for SDA */ unsigned int scl_pin; /* GPIO pin ID to use for SCL */ + bool has_pfunc; /*chip has a ICPFUNC register */ }; /* for board setup code */ |