diff options
Diffstat (limited to 'drivers/i2c/muxes/i2c-arb-gpio-challenge.c')
| -rw-r--r-- | drivers/i2c/muxes/i2c-arb-gpio-challenge.c | 79 |
1 files changed, 27 insertions, 52 deletions
diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c index 255c598dcfc8..6dc88902c189 100644 --- a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c +++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c @@ -6,12 +6,11 @@ */ #include <linux/delay.h> -#include <linux/gpio.h> +#include <linux/gpio/consumer.h> #include <linux/kernel.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> #include <linux/module.h> -#include <linux/of_gpio.h> #include <linux/platform_device.h> #include <linux/slab.h> @@ -19,22 +18,16 @@ /** * 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; @@ -55,15 +48,15 @@ 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; } @@ -72,13 +65,13 @@ 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; @@ -94,7 +87,7 @@ 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; @@ -107,8 +100,7 @@ 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 */ @@ -129,45 +121,28 @@ 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 */ |