Most modern platforms provide a dts with description of the devices available in the system. It may also include i2c-gpio-mux'es. Up until now the i2c-mux-gpio driver supported it' dts nodes, but performed the GPIOs request by means of legacy GPIO API, which by design and due to being legacy doesn't know anything about of/dtb/fdt/dts stuff. It means even though the i2c-gpio-mux dts nodes are successfully mapped to the kernel i2c-mux devices, the GPIOs used for initialization are requested without OF_GPIO_* flags setup. It causes problems on the platforms which fully rely on dts and reside, for instance, i2c-gpio-muxes with active low, push-pull, open drain or open source GPIOs connected. It is fixed by implementing a dedicated method for full dts-based GPIOs requests. It is mostly similar to the platform one, but utilizes the gpiod_get_from_of_node() method to request the GPIOs. Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx> --- Changelog v2 - Remove fallback pattern when selecting the dt- or plat-based GPIOs request methods. - Use a dedicated initial_state field in the "gpiomux" structure to select a proper channel initially. --- drivers/i2c/muxes/i2c-mux-gpio.c | 68 ++++++++++++++++++++++++-------- 1 file changed, 52 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c index e10f72706b99..d1a9c56fa1ec 100644 --- a/drivers/i2c/muxes/i2c-mux-gpio.c +++ b/drivers/i2c/muxes/i2c-mux-gpio.c @@ -66,8 +66,8 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux, struct device_node *np = pdev->dev.of_node; struct device_node *adapter_np, *child; struct i2c_adapter *adapter; - unsigned *values, *gpios; - int i = 0, ret; + unsigned int *values; + int i = 0; if (!np) return -ENODEV; @@ -110,24 +110,48 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux, return -EINVAL; } - gpios = devm_kcalloc(&pdev->dev, - mux->data.n_gpios, sizeof(*mux->data.gpios), - GFP_KERNEL); - if (!gpios) { - dev_err(&pdev->dev, "Cannot allocate gpios array"); - return -ENOMEM; - } + return 0; +} + +static int i2c_mux_gpio_request_dt(struct gpiomux *mux, + struct platform_device *pdev) +{ + struct i2c_mux_core *muxc = platform_get_drvdata(pdev); + struct device_node *np = pdev->dev.of_node; + struct i2c_adapter *root; + struct device *gpio_dev; + enum gpiod_flags dflags; + int i, ret; + + root = i2c_root_adapter(&muxc->parent->dev); for (i = 0; i < mux->data.n_gpios; i++) { - ret = of_get_named_gpio(np, "mux-gpios", i); - if (ret < 0) - return ret; - gpios[i] = ret; - } + if (mux->initial_state & (1 << i)) + dflags = GPIOD_OUT_HIGH; + else + dflags = GPIOD_OUT_LOW; + + mux->gpios[i] = gpiod_get_from_of_node(np, "mux-gpios", i, + dflags, "i2c-mux-gpio"); + if (IS_ERR(mux->gpios[i])) { + ret = PTR_ERR(mux->gpios[i]); + goto err_request_gpio; + } + + if (!muxc->mux_locked) + continue; - mux->data.gpios = gpios; + gpio_dev = &mux->gpios[i]->gdev->dev; + muxc->mux_locked = i2c_root_adapter(gpio_dev) == root; + } return 0; + +err_request_gpio: + for (i--; i >= 0; i--) + gpiod_free(mux->gpios[i]); + + return ret; } #else static int i2c_mux_gpio_probe_dt(struct gpiomux *mux, @@ -135,6 +159,12 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux, { return -EINVAL; } + +static int i2c_mux_gpio_request_dt(struct gpiomux *mux, + struct platform_device *pdev) +{ + return -EINVAL; +} #endif static int i2c_mux_gpio_probe_plat(struct gpiomux *mux, @@ -172,6 +202,9 @@ static int i2c_mux_gpio_request_plat(struct gpiomux *mux, struct device *gpio_dev; int i, ret; + if (!mux->data.gpios) + return -EINVAL; + root = i2c_root_adapter(&muxc->parent->dev); for (i = 0; i < mux->data.n_gpios; i++) { @@ -263,7 +296,10 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) mux->initial_state = mux->data.values[0]; } - ret = i2c_mux_gpio_request_plat(mux, pdev); + if (!dev_get_platdata(&pdev->dev)) + ret = i2c_mux_gpio_request_dt(mux, pdev); + else + ret = i2c_mux_gpio_request_plat(mux, pdev); if (ret) goto alloc_failed; -- 2.21.0