From d9a183bfd29d44c927b3920ae49ba2f682793976 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sat, 1 Jun 2019 18:59:31 +0200 Subject: i2c: mux: arb-gpio: Rewrite to use GPIO descriptors Instead of complex code picking GPIOs out of the device tree and keeping track of polarity for each GPIO line, use descriptors and pull polarity handling into the gpiolib. We look for "our-claim" and "their-claim" since the gpiolib code will try e.g. "our-claim-gpios" and "our-claim-gpio" in turn to locate these GPIO lines from the device tree. Cc: Krzysztof Kozlowski Cc: Marek Szyprowski Cc: Doug Anderson Signed-off-by: Linus Walleij Tested-by: Marek Szyprowski Reviewed-by: Douglas Anderson Signed-off-by: Peter Rosin --- drivers/i2c/muxes/i2c-arb-gpio-challenge.c | 79 ++++++++++-------------------- 1 file changed, 27 insertions(+), 52 deletions(-) (limited to 'drivers/i2c/muxes') diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c index 812b8cff265f..a664f637bc3d 100644 --- a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c +++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c @@ -15,12 +15,11 @@ */ #include -#include +#include #include #include #include #include -#include #include #include @@ -28,22 +27,16 @@ /** * struct i2c_arbitrator_data - Driver data for I2C arbitrator * - * @our_gpio: GPIO we'll use to claim. - * @our_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO == - * this then consider it released. - * @their_gpio: GPIO that the other side will use to claim. - * @their_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO == - * this then consider it released. + * @our_gpio: GPIO descriptor we'll use to claim. + * @their_gpio: GPIO descriptor that the other side will use to claim. * @slew_delay_us: microseconds to wait for a GPIO to go high. * @wait_retry_us: we'll attempt another claim after this many microseconds. * @wait_free_us: we'll give up after this many microseconds. */ struct i2c_arbitrator_data { - int our_gpio; - int our_gpio_release; - int their_gpio; - int their_gpio_release; + struct gpio_desc *our_gpio; + struct gpio_desc *their_gpio; unsigned int slew_delay_us; unsigned int wait_retry_us; unsigned int wait_free_us; @@ -64,15 +57,15 @@ static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan) stop_time = jiffies + usecs_to_jiffies(arb->wait_free_us) + 1; do { /* Indicate that we want to claim the bus */ - gpio_set_value(arb->our_gpio, !arb->our_gpio_release); + gpiod_set_value(arb->our_gpio, 1); udelay(arb->slew_delay_us); /* Wait for the other master to release it */ stop_retry = jiffies + usecs_to_jiffies(arb->wait_retry_us) + 1; while (time_before(jiffies, stop_retry)) { - int gpio_val = !!gpio_get_value(arb->their_gpio); + int gpio_val = gpiod_get_value(arb->their_gpio); - if (gpio_val == arb->their_gpio_release) { + if (!gpio_val) { /* We got it, so return */ return 0; } @@ -81,13 +74,13 @@ static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan) } /* It didn't release, so give up, wait, and try again */ - gpio_set_value(arb->our_gpio, arb->our_gpio_release); + gpiod_set_value(arb->our_gpio, 0); usleep_range(arb->wait_retry_us, arb->wait_retry_us * 2); } while (time_before(jiffies, stop_time)); /* Give up, release our claim */ - gpio_set_value(arb->our_gpio, arb->our_gpio_release); + gpiod_set_value(arb->our_gpio, 0); udelay(arb->slew_delay_us); dev_err(muxc->dev, "Could not claim bus, timeout\n"); return -EBUSY; @@ -103,7 +96,7 @@ static int i2c_arbitrator_deselect(struct i2c_mux_core *muxc, u32 chan) const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc); /* Release the bus and wait for the other master to notice */ - gpio_set_value(arb->our_gpio, arb->our_gpio_release); + gpiod_set_value(arb->our_gpio, 0); udelay(arb->slew_delay_us); return 0; @@ -116,8 +109,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) struct device_node *parent_np; struct i2c_mux_core *muxc; struct i2c_arbitrator_data *arb; - enum of_gpio_flags gpio_flags; - unsigned long out_init; + struct gpio_desc *dummy; int ret; /* We only support probing from device tree; no platform_data */ @@ -138,45 +130,28 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) platform_set_drvdata(pdev, muxc); - /* Request GPIOs */ - ret = of_get_named_gpio_flags(np, "our-claim-gpio", 0, &gpio_flags); - if (!gpio_is_valid(ret)) { - if (ret != -EPROBE_DEFER) - dev_err(dev, "Error getting our-claim-gpio\n"); - return ret; - } - arb->our_gpio = ret; - arb->our_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW); - out_init = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? - GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; - ret = devm_gpio_request_one(dev, arb->our_gpio, out_init, - "our-claim-gpio"); - if (ret) { - if (ret != -EPROBE_DEFER) - dev_err(dev, "Error requesting our-claim-gpio\n"); - return ret; + /* Request GPIOs, our GPIO as unclaimed to begin with */ + arb->our_gpio = devm_gpiod_get(dev, "our-claim", GPIOD_OUT_LOW); + if (IS_ERR(arb->our_gpio)) { + dev_err(dev, "could not get \"our-claim\" GPIO (%ld)\n", + PTR_ERR(arb->our_gpio)); + return PTR_ERR(arb->our_gpio); } - ret = of_get_named_gpio_flags(np, "their-claim-gpios", 0, &gpio_flags); - if (!gpio_is_valid(ret)) { - if (ret != -EPROBE_DEFER) - dev_err(dev, "Error getting their-claim-gpio\n"); - return ret; - } - arb->their_gpio = ret; - arb->their_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW); - ret = devm_gpio_request_one(dev, arb->their_gpio, GPIOF_IN, - "their-claim-gpio"); - if (ret) { - if (ret != -EPROBE_DEFER) - dev_err(dev, "Error requesting their-claim-gpio\n"); - return ret; + arb->their_gpio = devm_gpiod_get(dev, "their-claim", GPIOD_IN); + if (IS_ERR(arb->their_gpio)) { + dev_err(dev, "could not get \"their-claim\" GPIO (%ld)\n", + PTR_ERR(arb->their_gpio)); + return PTR_ERR(arb->their_gpio); } /* At the moment we only support a single two master (us + 1 other) */ - if (gpio_is_valid(of_get_named_gpio(np, "their-claim-gpios", 1))) { + dummy = devm_gpiod_get_index(dev, "their-claim", 1, GPIOD_IN); + if (!IS_ERR(dummy)) { dev_err(dev, "Only one other master is supported\n"); return -EINVAL; + } else if (PTR_ERR(dummy) == -EPROBE_DEFER) { + return -EPROBE_DEFER; } /* Arbitration parameters */ -- cgit v1.2.3 From 90af27317b63403bce3874566b71883fc1e1f459 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 3 Jun 2019 09:53:35 -0500 Subject: i2c: mux: pinctrl: use flexible-array member and struct_size() helper Update the code to use a flexible array member instead of a pointer in structure i2c_mux_pinctrl and use the struct_size() helper. Also, make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes, in particular in the context in which this code is being used. So, replace the following form: sizeof(*mux) + num_names * sizeof(*mux->states) with: struct_size(mux, states, num_names) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Peter Rosin --- drivers/i2c/muxes/i2c-mux-pinctrl.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/i2c/muxes') diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c index cc6818aabab5..ff3e8c9d4dd8 100644 --- a/drivers/i2c/muxes/i2c-mux-pinctrl.c +++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c @@ -27,7 +27,7 @@ struct i2c_mux_pinctrl { struct pinctrl *pinctrl; - struct pinctrl_state **states; + struct pinctrl_state *states[]; }; static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan) @@ -104,14 +104,13 @@ static int i2c_mux_pinctrl_probe(struct platform_device *pdev) return PTR_ERR(parent); muxc = i2c_mux_alloc(parent, dev, num_names, - sizeof(*mux) + num_names * sizeof(*mux->states), + struct_size(mux, states, num_names), 0, i2c_mux_pinctrl_select, NULL); if (!muxc) { ret = -ENOMEM; goto err_put_parent; } mux = i2c_mux_priv(muxc); - mux->states = (struct pinctrl_state **)(mux + 1); platform_set_drvdata(pdev, muxc); -- cgit v1.2.3 From d308dfbf62eff897d71968d764f21a78678ee0a5 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 18 Jun 2019 12:58:33 +0200 Subject: i2c: mux/i801: Switch to use descriptor passing This switches the i801 GPIO mux to use GPIO descriptors for handling the GPIO lines. The previous hack which was reaching inside the GPIO chips etc cannot live on. We pass descriptors along with the GPIO mux device at creation instead. The GPIO mux was only used by way of platform data with a platform device from one place in the kernel: the i801 i2c bus driver. Let's just associate the GPIO descriptor table with the actual device like everyone else and dynamically create a descriptor table passed along with the GPIO i2c mux. This enables simplification of the GPIO i2c mux driver to use only the descriptor API and the OF probe path gets simplified in the process. The i801 driver was registering the GPIO i2c mux with PLATFORM_DEVID_AUTO which would make it hard to predict the device name and assign the descriptor table properly, but this seems to be a mistake to begin with: all of the GPIO mux devices are hardcoded to look up GPIO lines from the "gpio_ich" GPIO chip. If there are more than one mux, there is certainly more than one gpio chip as well, and then we have more serious problems. Switch to PLATFORM_DEVID_NONE instead. There can be only one. Cc: Mika Westerberg Cc: Andy Shevchenko Cc: Peter Rosin Cc: Jean Delvare Signed-off-by: Serge Semin Signed-off-by: Linus Walleij Reviewed-by: Andy Shevchenko Reviewed-by: Mika Westerberg [Removed a newline, suggested by Andy. /Peter] Signed-off-by: Peter Rosin --- drivers/i2c/muxes/i2c-mux-gpio.c | 116 ++++++++++----------------------------- 1 file changed, 30 insertions(+), 86 deletions(-) (limited to 'drivers/i2c/muxes') diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c index 13882a2a4f60..fd482feafb19 100644 --- a/drivers/i2c/muxes/i2c-mux-gpio.c +++ b/drivers/i2c/muxes/i2c-mux-gpio.c @@ -14,13 +14,14 @@ #include #include #include -#include +#include +#include +/* FIXME: stop poking around inside gpiolib */ #include "../../gpio/gpiolib.h" -#include struct gpiomux { struct i2c_mux_gpio_platform_data data; - unsigned gpio_base; + int ngpios; struct gpio_desc **gpios; }; @@ -30,8 +31,7 @@ static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val) values[0] = val; - gpiod_set_array_value_cansleep(mux->data.n_gpios, mux->gpios, NULL, - values); + gpiod_set_array_value_cansleep(mux->ngpios, mux->gpios, NULL, values); } static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan) @@ -52,12 +52,6 @@ static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan) return 0; } -static int match_gpio_chip_by_label(struct gpio_chip *chip, - void *data) -{ - return !strcmp(chip->label, data); -} - #ifdef CONFIG_OF static int i2c_mux_gpio_probe_dt(struct gpiomux *mux, struct platform_device *pdev) @@ -65,8 +59,8 @@ 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 *values; + int i = 0; if (!np) return -ENODEV; @@ -103,29 +97,6 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux, if (of_property_read_u32(np, "idle-state", &mux->data.idle)) mux->data.idle = I2C_MUX_GPIO_NO_IDLE; - mux->data.n_gpios = of_gpio_named_count(np, "mux-gpios"); - if (mux->data.n_gpios < 0) { - dev_err(&pdev->dev, "Missing mux-gpios property in the DT.\n"); - 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; - } - - 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; - } - - mux->data.gpios = gpios; - return 0; } #else @@ -142,8 +113,8 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) struct gpiomux *mux; struct i2c_adapter *parent; struct i2c_adapter *root; - unsigned initial_state, gpio_base; - int i, ret; + unsigned initial_state; + int i, ngpios, ret; mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL); if (!mux) @@ -158,29 +129,19 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) sizeof(mux->data)); } - /* - * If a GPIO chip name is provided, the GPIO pin numbers provided are - * relative to its base GPIO number. Otherwise they are absolute. - */ - if (mux->data.gpio_chip) { - struct gpio_chip *gpio; - - gpio = gpiochip_find(mux->data.gpio_chip, - match_gpio_chip_by_label); - if (!gpio) - return -EPROBE_DEFER; - - gpio_base = gpio->base; - } else { - gpio_base = 0; + ngpios = gpiod_count(&pdev->dev, "mux"); + if (ngpios <= 0) { + dev_err(&pdev->dev, "no valid gpios provided\n"); + return ngpios ?: -EINVAL; } + mux->ngpios = ngpios; parent = i2c_get_adapter(mux->data.parent); if (!parent) return -EPROBE_DEFER; muxc = i2c_mux_alloc(parent, &pdev->dev, mux->data.n_values, - mux->data.n_gpios * sizeof(*mux->gpios), 0, + ngpios * sizeof(*mux->gpios), 0, i2c_mux_gpio_select, NULL); if (!muxc) { ret = -ENOMEM; @@ -194,7 +155,6 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) root = i2c_root_adapter(&parent->dev); muxc->mux_locked = true; - mux->gpio_base = gpio_base; if (mux->data.idle != I2C_MUX_GPIO_NO_IDLE) { initial_state = mux->data.idle; @@ -203,34 +163,28 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) initial_state = mux->data.values[0]; } - for (i = 0; i < mux->data.n_gpios; i++) { + for (i = 0; i < ngpios; i++) { struct device *gpio_dev; - struct gpio_desc *gpio_desc; - - ret = gpio_request(gpio_base + mux->data.gpios[i], "i2c-mux-gpio"); - if (ret) { - dev_err(&pdev->dev, "Failed to request GPIO %d\n", - mux->data.gpios[i]); - goto err_request_gpio; + struct gpio_desc *gpiod; + enum gpiod_flags flag; + + if (initial_state & BIT(i)) + flag = GPIOD_OUT_HIGH; + else + flag = GPIOD_OUT_LOW; + gpiod = devm_gpiod_get_index(&pdev->dev, "mux", i, flag); + if (IS_ERR(gpiod)) { + ret = PTR_ERR(gpiod); + goto alloc_failed; } - ret = gpio_direction_output(gpio_base + mux->data.gpios[i], - initial_state & (1 << i)); - if (ret) { - dev_err(&pdev->dev, - "Failed to set direction of GPIO %d to output\n", - mux->data.gpios[i]); - i++; /* gpio_request above succeeded, so must free */ - goto err_request_gpio; - } - - gpio_desc = gpio_to_desc(gpio_base + mux->data.gpios[i]); - mux->gpios[i] = gpio_desc; + mux->gpios[i] = gpiod; if (!muxc->mux_locked) continue; - gpio_dev = &gpio_desc->gdev->dev; + /* FIXME: find a proper way to access the GPIO device */ + gpio_dev = &gpiod->gdev->dev; muxc->mux_locked = i2c_root_adapter(gpio_dev) == root; } @@ -253,10 +207,6 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev) add_adapter_failed: i2c_mux_del_adapters(muxc); - i = mux->data.n_gpios; -err_request_gpio: - for (; i > 0; i--) - gpio_free(gpio_base + mux->data.gpios[i - 1]); alloc_failed: i2c_put_adapter(parent); @@ -266,14 +216,8 @@ alloc_failed: static int i2c_mux_gpio_remove(struct platform_device *pdev) { struct i2c_mux_core *muxc = platform_get_drvdata(pdev); - struct gpiomux *mux = i2c_mux_priv(muxc); - int i; i2c_mux_del_adapters(muxc); - - for (i = 0; i < mux->data.n_gpios; i++) - gpio_free(mux->gpio_base + mux->data.gpios[i]); - i2c_put_adapter(muxc->parent); return 0; -- cgit v1.2.3