From 0c2a34937f7e4c4776bb261114c475392da2355c Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 30 Jun 2020 18:24:40 +0200 Subject: i2c: revert "i2c: core: Allow drivers to disable i2c-core irq mapping" This manually reverts commit d1d84bb95364ed604015c2b788caaf3dbca0262f. The only user has gone two years ago with commit 589edb56b424 ("ACPI / scan: Create platform device for INT33FE ACPI nodes") and no new user has showed up. Remove and hope we will never need it again. Signed-off-by: Wolfram Sang Acked-by: Hans de Goede Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index b8b8963f8bb9..098405df431f 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -231,7 +231,6 @@ enum i2c_alert_protocol { * @detect: Callback for device detection * @address_list: The I2C addresses to probe (for detect) * @clients: List of detected clients we created (for i2c-core use only) - * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping * * The driver.owner field should be set to the module owner of this driver. * The driver.name field should be set to the name of this driver. @@ -290,8 +289,6 @@ struct i2c_driver { int (*detect)(struct i2c_client *client, struct i2c_board_info *info); const unsigned short *address_list; struct list_head clients; - - bool disable_i2c_core_irq_mapping; }; #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) -- cgit v1.2.3 From 75820314de26b00aaea0d0e79269c0d17914c5c4 Mon Sep 17 00:00:00 2001 From: Codrin Ciubotariu Date: Tue, 4 Aug 2020 12:59:24 +0300 Subject: i2c: core: add generic I2C GPIO recovery Multiple I2C bus drivers use similar bindings to obtain information needed for I2C recovery. For example, for platforms using device-tree, the properties look something like this: &i2c { ... pinctrl-names = "default", "gpio"; pinctrl-0 = <&pinctrl_i2c_default>; pinctrl-1 = <&pinctrl_i2c_gpio>; sda-gpios = <&pio 0 GPIO_ACTIVE_HIGH>; scl-gpios = <&pio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; ... } For this reason, we can add this common initialization in the core. This way, other I2C bus drivers will be able to support GPIO recovery just by providing a pointer to platform's pinctrl and calling i2c_recover_bus() when SDA is stuck low. Signed-off-by: Codrin Ciubotariu [wsa: inverted one logic for better readability, minor update to kdoc] Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core-base.c | 126 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/i2c.h | 11 ++++ 2 files changed, 137 insertions(+) (limited to 'include') diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 69217d2193da..ece25560eae4 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -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; } @@ -251,6 +256,125 @@ int i2c_recover_bus(struct i2c_adapter *adap) } EXPORT_SYMBOL_GPL(i2c_recover_bus); +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 void i2c_init_recovery(struct i2c_adapter *adap) { struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; @@ -259,6 +383,8 @@ static void i2c_init_recovery(struct i2c_adapter *adap) if (!bri) return; + i2c_gpio_init_recovery(adap); + if (!bri->recover_bus) { err_str = "no recover_bus() found"; goto err; diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 8ea9c3f86dba..d387d3786429 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -606,6 +606,14 @@ struct i2c_timings { * may configure padmux here for SDA/SCL line or something else they want. * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. + * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. + * Optional. + * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned + * to the I2C bus. Optional. Populated internally for GPIO recovery, if + * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. + * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as + * GPIOs. Optional. Populated internally for GPIO recovery, if this state + * is called "gpio" or "recovery" and pinctrl is valid. */ struct i2c_bus_recovery_info { int (*recover_bus)(struct i2c_adapter *adap); @@ -622,6 +630,9 @@ struct i2c_bus_recovery_info { /* gpio recovery */ struct gpio_desc *scl_gpiod; struct gpio_desc *sda_gpiod; + struct pinctrl *pinctrl; + struct pinctrl_state *pins_default; + struct pinctrl_state *pins_gpio; }; int i2c_recover_bus(struct i2c_adapter *adap); -- cgit v1.2.3