diff options
Diffstat (limited to 'drivers/i2c/i2c-core-base.c')
| -rw-r--r-- | drivers/i2c/i2c-core-base.c | 158 |
1 files changed, 143 insertions, 15 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 26f03a14a478..34a9609f256d 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -32,6 +32,7 @@ #include <linux/of_device.h> #include <linux/of.h> #include <linux/of_irq.h> +#include <linux/pinctrl/consumer.h> #include <linux/pm_domain.h> #include <linux/pm_runtime.h> #include <linux/pm_wakeirq.h> @@ -181,6 +182,8 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap) if (bri->prepare_recovery) bri->prepare_recovery(adap); + if (bri->pinctrl) + pinctrl_select_state(bri->pinctrl, bri->pins_gpio); /* * If we can set SDA, we will always create a STOP to ensure additional @@ -236,6 +239,8 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap) if (bri->unprepare_recovery) bri->unprepare_recovery(adap); + if (bri->pinctrl) + pinctrl_select_state(bri->pinctrl, bri->pins_default); return ret; } @@ -251,13 +256,135 @@ int i2c_recover_bus(struct i2c_adapter *adap) } EXPORT_SYMBOL_GPL(i2c_recover_bus); -static void i2c_init_recovery(struct i2c_adapter *adap) +static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap) +{ + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; + struct device *dev = &adap->dev; + struct pinctrl *p = bri->pinctrl; + + /* + * we can't change states without pinctrl, so remove the states if + * populated + */ + if (!p) { + bri->pins_default = NULL; + bri->pins_gpio = NULL; + return; + } + + if (!bri->pins_default) { + bri->pins_default = pinctrl_lookup_state(p, + PINCTRL_STATE_DEFAULT); + if (IS_ERR(bri->pins_default)) { + dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n"); + bri->pins_default = NULL; + } + } + if (!bri->pins_gpio) { + bri->pins_gpio = pinctrl_lookup_state(p, "gpio"); + if (IS_ERR(bri->pins_gpio)) + bri->pins_gpio = pinctrl_lookup_state(p, "recovery"); + + if (IS_ERR(bri->pins_gpio)) { + dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n"); + bri->pins_gpio = NULL; + } + } + + /* for pinctrl state changes, we need all the information */ + if (bri->pins_default && bri->pins_gpio) { + dev_info(dev, "using pinctrl states for GPIO recovery"); + } else { + bri->pinctrl = NULL; + bri->pins_default = NULL; + bri->pins_gpio = NULL; + } +} + +static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap) +{ + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; + struct device *dev = &adap->dev; + struct gpio_desc *gpiod; + int ret = 0; + + /* + * don't touch the recovery information if the driver is not using + * generic SCL recovery + */ + if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery) + return 0; + + /* + * pins might be taken as GPIO, so we should inform pinctrl about + * this and move the state to GPIO + */ + if (bri->pinctrl) + pinctrl_select_state(bri->pinctrl, bri->pins_gpio); + + /* + * if there is incomplete or no recovery information, see if generic + * GPIO recovery is available + */ + if (!bri->scl_gpiod) { + gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN); + if (PTR_ERR(gpiod) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto cleanup_pinctrl_state; + } + if (!IS_ERR(gpiod)) { + bri->scl_gpiod = gpiod; + bri->recover_bus = i2c_generic_scl_recovery; + dev_info(dev, "using generic GPIOs for recovery\n"); + } + } + + /* SDA GPIOD line is optional, so we care about DEFER only */ + if (!bri->sda_gpiod) { + /* + * We have SCL. Pull SCL low and wait a bit so that SDA glitches + * have no effect. + */ + gpiod_direction_output(bri->scl_gpiod, 0); + udelay(10); + gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN); + + /* Wait a bit in case of a SDA glitch, and then release SCL. */ + udelay(10); + gpiod_direction_output(bri->scl_gpiod, 1); + + if (PTR_ERR(gpiod) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto cleanup_pinctrl_state; + } + if (!IS_ERR(gpiod)) + bri->sda_gpiod = gpiod; + } + +cleanup_pinctrl_state: + /* change the state of the pins back to their default state */ + if (bri->pinctrl) + pinctrl_select_state(bri->pinctrl, bri->pins_default); + + return ret; +} + +static int i2c_gpio_init_recovery(struct i2c_adapter *adap) +{ + i2c_gpio_init_pinctrl_recovery(adap); + return i2c_gpio_init_generic_recovery(adap); +} + +static int i2c_init_recovery(struct i2c_adapter *adap) { struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; char *err_str; if (!bri) - return; + return 0; + + if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER) + return -EPROBE_DEFER; if (!bri->recover_bus) { err_str = "no recover_bus() found"; @@ -273,10 +400,7 @@ static void i2c_init_recovery(struct i2c_adapter *adap) if (gpiod_get_direction(bri->sda_gpiod) == 0) bri->set_sda = set_sda_gpio_value; } - return; - } - - if (bri->recover_bus == i2c_generic_scl_recovery) { + } else if (bri->recover_bus == i2c_generic_scl_recovery) { /* Generic SCL recovery */ if (!bri->set_scl || !bri->get_scl) { err_str = "no {get|set}_scl() found"; @@ -288,10 +412,12 @@ static void i2c_init_recovery(struct i2c_adapter *adap) } } - return; + return 0; err: dev_err(&adap->dev, "Not using recovery: %s\n", err_str); adap->bus_recovery_info = NULL; + + return -EINVAL; } static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) @@ -319,11 +445,9 @@ static int i2c_device_probe(struct device *dev) if (!client) return 0; - driver = to_i2c_driver(dev->driver); - client->irq = client->init_irq; - if (!client->irq && !driver->disable_i2c_core_irq_mapping) { + if (!client->irq) { int irq = -ENOENT; if (client->flags & I2C_CLIENT_HOST_NOTIFY) { @@ -349,6 +473,8 @@ static int i2c_device_probe(struct device *dev) client->irq = irq; } + driver = to_i2c_driver(dev->driver); + /* * An I2C ID table is not mandatory, if and only if, a suitable OF * or ACPI ID table is supplied for the probing device. @@ -1227,7 +1353,7 @@ static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) return 0; - domain = irq_domain_create_linear(adap->dev.fwnode, + domain = irq_domain_create_linear(adap->dev.parent->fwnode, I2C_ADDR_7BITS_COUNT, &i2c_host_notify_irq_ops, adap); if (!domain) @@ -1318,12 +1444,16 @@ static int i2c_register_adapter(struct i2c_adapter *adap) if (res) goto out_reg; - dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); - pm_runtime_no_callbacks(&adap->dev); pm_suspend_ignore_children(&adap->dev, true); pm_runtime_enable(&adap->dev); + res = i2c_init_recovery(adap); + if (res == -EPROBE_DEFER) + goto out_reg; + + dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); + #ifdef CONFIG_I2C_COMPAT res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, adap->dev.parent); @@ -1332,8 +1462,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap) "Failed to create compatibility class link\n"); #endif - i2c_init_recovery(adap); - /* create pre-declared device nodes */ of_i2c_register_devices(adap); i2c_acpi_register_devices(adap); |