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 or open drain 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. Finally the platform code i2c-gpio-mux devices are also supported. So the fallback to dtb is performed only if array with GPIOs isn't detected. Signed-off-by: Serge Semin <[email protected]> --- drivers/i2c/muxes/i2c-mux-gpio.c | 65 ++++++++++++++++++++++++-------- 1 file changed, 50 insertions(+), 15 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c index 317c019e1415..e5e10ba35ad9 100644 --- a/drivers/i2c/muxes/i2c-mux-gpio.c +++ b/drivers/i2c/muxes/i2c-mux-gpio.c @@ -65,8 +65,8 @@ 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; @@ -109,24 +109,48 @@ 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->data.idle & (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; + } - mux->data.gpios = gpios; + if (!muxc->mux_locked) + continue; + + 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, @@ -134,6 +158,12 @@ 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, @@ -174,6 +204,9 @@ 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++) { @@ -267,6 +300,8 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) mux->data.idle = mux->data.values[0]; ret = i2c_mux_gpio_request_plat(mux, pdev); + if (ret) + ret = i2c_mux_gpio_request_dt(mux, pdev); if (ret) goto alloc_failed; -- 2.21.0
