diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-imx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 9782527a8668..54a4b349f76e 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -50,6 +50,7 @@ #include <linux/slab.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/of_gpio.h> #include <linux/of_i2c.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_data/i2c-imx.h> @@ -495,16 +496,71 @@ static struct i2c_algorithm i2c_imx_algo = { .functionality = i2c_imx_func, }; +static int of_i2c_imx_get_pins(struct device_node *np, + unsigned int *sda_pin, unsigned int *scl_pin) +{ + if (of_gpio_count(np) < 2) + return -ENODEV; + + *sda_pin = of_get_gpio(np, 0); + *scl_pin = of_get_gpio(np, 1); + if (!gpio_is_valid(*sda_pin) || !gpio_is_valid(*scl_pin)) { + pr_err("%s: invalid GPIO pins, sda=%d/scl=%d\n", + np->full_name, *sda_pin, *scl_pin); + return -ENODEV; + } + + return 0; +} + +/* i2c bus recovery routines */ +static int get_scl_gpio_value(struct i2c_adapter *adap) +{ + return gpio_get_value(adap->bus_recovery_info->scl_gpio); +} + +static void set_scl_gpio_value(struct i2c_adapter *adap, int val) +{ + gpio_set_value(adap->bus_recovery_info->scl_gpio, val); +} + +static int get_sda_gpio_value(struct i2c_adapter *adap) +{ + return gpio_get_value(adap->bus_recovery_info->sda_gpio); +} + +int i2c_imx_recover_bus(struct i2c_adapter *adap) +{ + /* i2c_imx_(un)prepare_recovery can not be used for pinmuxing, as we + * need the data from struct i2c_adapter */ + int ret; + + if(!devm_pinctrl_get_select(adap->dev.parent, "recovery")) { + dev_err(adap->dev.parent, "%s> switching to 'recover' pinmux failed\n", __func__); + } + + ret = i2c_generic_gpio_recovery(adap); + + if(!devm_pinctrl_get_select_default(adap->dev.parent)) { + dev_err(adap->dev.parent, "<%s> switching from 'recover' to 'default' pinmux failed\n", __func__); + } + + return ret; +} + static int __init i2c_imx_probe(struct platform_device *pdev) { const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids, &pdev->dev); struct imx_i2c_struct *i2c_imx; + struct i2c_bus_recovery_info *bri; struct resource *res; struct imxi2c_platform_data *pdata = pdev->dev.platform_data; struct pinctrl *pinctrl; void __iomem *base; int irq, ret; + int sda_gpio = -1; + int scl_gpio = -1; dev_dbg(&pdev->dev, "<%s>\n", __func__); @@ -570,6 +626,23 @@ static int __init i2c_imx_probe(struct platform_device *pdev) /* Set up adapter data */ i2c_set_adapdata(&i2c_imx->adapter, i2c_imx); + /* Set up adapter recovery info */ + if (of_i2c_imx_get_pins(pdev->dev.of_node, &sda_gpio, &scl_gpio) >= 0) { + bri = devm_kzalloc(&pdev->dev, + sizeof(struct i2c_bus_recovery_info), GFP_KERNEL); + if (!bri) + dev_info(&pdev->dev, "can't allocate i2c recovery struct, recovery will not work\n"); + else { + bri->recover_bus = i2c_imx_recover_bus; + bri->get_sda = get_sda_gpio_value; + bri->get_scl = get_scl_gpio_value; + bri->set_scl = set_scl_gpio_value; + bri->sda_gpio = sda_gpio; + bri->scl_gpio = scl_gpio; + i2c_imx->adapter.bus_recovery_info = bri; + } + } + /* Set up clock divider */ i2c_imx->bitrate = IMX_I2C_BIT_RATE; ret = of_property_read_u32(pdev->dev.of_node, |