* [PATCH v5 0/2] gpio: Add gpio-latch driver
@ 2022-10-07 11:46 Sascha Hauer
2022-10-07 11:46 ` [PATCH v5 1/2] gpio: Add gpio latch driver Sascha Hauer
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Sascha Hauer @ 2022-10-07 11:46 UTC (permalink / raw)
To: linux-gpio
Cc: devicetree, linux-kernel, Linus Walleij, Bartosz Golaszewski,
kernel, Serge Semin, Sascha Hauer
This series includes the changes requested by Serge Semin for v4.
Sascha
Sascha Hauer (2):
gpio: Add gpio latch driver
dt-bindings: gpio: Add gpio-latch binding document
.../devicetree/bindings/gpio/gpio-latch.yaml | 94 ++++++++
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-latch.c | 220 ++++++++++++++++++
4 files changed, 321 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-latch.yaml
create mode 100644 drivers/gpio/gpio-latch.c
--
2.30.2
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v5 1/2] gpio: Add gpio latch driver 2022-10-07 11:46 [PATCH v5 0/2] gpio: Add gpio-latch driver Sascha Hauer @ 2022-10-07 11:46 ` Sascha Hauer 2022-10-07 16:29 ` Serge Semin 2022-10-17 8:50 ` Linus Walleij 2022-10-07 11:46 ` [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document Sascha Hauer 2022-10-25 9:39 ` [PATCH v5 0/2] gpio: Add gpio-latch driver Bartosz Golaszewski 2 siblings, 2 replies; 8+ messages in thread From: Sascha Hauer @ 2022-10-07 11:46 UTC (permalink / raw) To: linux-gpio Cc: devicetree, linux-kernel, Linus Walleij, Bartosz Golaszewski, kernel, Serge Semin, Sascha Hauer This driver implements a GPIO multiplexer based on latches connected to other GPIOs. A set of data GPIOs is connected to the data input of multiple latches. The clock input of each latch is driven by another set of GPIOs. With two 8-bit latches 10 GPIOs can be multiplexed into 16 GPIOs. GPOs might be a better term as in fact the multiplexed pins are output only. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> --- Notes: Changes since v4: - Use correct ndelay instead of udelay - Use #define for constant value - drop unnecessary delay Changes since v3: - Introduce delays between GPIO toggles as suggested by Serge Semin Changes since v2: - Fix inconsistent licensing - document locks - use regular bit operations - include linux/mod_devicetable.h rather than linux/of_device.h - Put spinlock and mutex into a union to make clear that only one of them is used - rename __gpio_latch_set to gpio_latch_set_unlocked Changes since v1: - Use gpiod_set_value_cansleep when the underlying GPIOs might sleep - Move MODULE_DEVICE_TABLE near to the end drivers/gpio/Kconfig | 6 ++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-latch.c | 220 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 227 insertions(+) create mode 100644 drivers/gpio/gpio-latch.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 0642f579196f2..e4603810ec910 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1690,6 +1690,12 @@ config GPIO_AGGREGATOR industrial control context, to be operated from userspace using the GPIO chardev interface. +config GPIO_LATCH + tristate "GPIO latch driver" + help + Say yes here to enable a driver for GPIO multiplexers based on latches + connected to other GPIOs. + config GPIO_MOCKUP tristate "GPIO Testing Driver" select IRQ_SIM diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index a0985d30f51bb..310fa08decc69 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_IT87) += gpio-it87.o obj-$(CONFIG_GPIO_IXP4XX) += gpio-ixp4xx.o obj-$(CONFIG_GPIO_JANZ_TTL) += gpio-janz-ttl.o obj-$(CONFIG_GPIO_KEMPLD) += gpio-kempld.o +obj-$(CONFIG_GPIO_LATCH) += gpio-latch.o obj-$(CONFIG_GPIO_LOGICVC) += gpio-logicvc.o obj-$(CONFIG_GPIO_LOONGSON1) += gpio-loongson1.o obj-$(CONFIG_GPIO_LOONGSON) += gpio-loongson.o diff --git a/drivers/gpio/gpio-latch.c b/drivers/gpio/gpio-latch.c new file mode 100644 index 0000000000000..24a8237b712b4 --- /dev/null +++ b/drivers/gpio/gpio-latch.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPIO latch driver + * + * Copyright (C) 2022 Sascha Hauer <s.hauer@pengutronix.de> + * + * This driver implements a GPIO (or better GPO as there is no input) + * multiplexer based on latches like this: + * + * CLK0 ----------------------. ,--------. + * CLK1 -------------------. `--------|> #0 | + * | | | + * OUT0 ----------------+--|-----------|D0 Q0|-----|< + * OUT1 --------------+-|--|-----------|D1 Q1|-----|< + * OUT2 ------------+-|-|--|-----------|D2 Q2|-----|< + * OUT3 ----------+-|-|-|--|-----------|D3 Q3|-----|< + * OUT4 --------+-|-|-|-|--|-----------|D4 Q4|-----|< + * OUT5 ------+-|-|-|-|-|--|-----------|D5 Q5|-----|< + * OUT6 ----+-|-|-|-|-|-|--|-----------|D6 Q6|-----|< + * OUT7 --+-|-|-|-|-|-|-|--|-----------|D7 Q7|-----|< + * | | | | | | | | | `--------' + * | | | | | | | | | + * | | | | | | | | | ,--------. + * | | | | | | | | `-----------|> #1 | + * | | | | | | | | | | + * | | | | | | | `--------------|D0 Q0|-----|< + * | | | | | | `----------------|D1 Q1|-----|< + * | | | | | `------------------|D2 Q2|-----|< + * | | | | `--------------------|D3 Q3|-----|< + * | | | `----------------------|D4 Q4|-----|< + * | | `------------------------|D5 Q5|-----|< + * | `--------------------------|D6 Q6|-----|< + * `----------------------------|D7 Q7|-----|< + * `--------' + * + * The above is just an example. The actual number of number of latches and + * the number of inputs per latch is derived from the number of GPIOs given + * in the corresponding device tree properties. + */ + +#include <linux/err.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/delay.h> + +#include "gpiolib.h" + +struct gpio_latch_priv { + struct gpio_chip gc; + struct gpio_descs *clk_gpios; + struct gpio_descs *latched_gpios; + int n_latched_gpios; + unsigned int setup_duration_ns; + unsigned int clock_duration_ns; + unsigned long *shadow; + /* + * Depending on whether any of the underlying GPIOs may sleep we either + * use a mutex or a spinlock to protect our shadow map. + */ + union { + struct mutex mutex; /* protects @shadow */ + spinlock_t spinlock; /* protects @shadow */ + }; +}; + +static int gpio_latch_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + return GPIO_LINE_DIRECTION_OUT; +} + +static void gpio_latch_set_unlocked(struct gpio_latch_priv *priv, + void (*set)(struct gpio_desc *desc, int value), + unsigned int offset, bool val) +{ + int latch = offset / priv->n_latched_gpios; + int i; + + assign_bit(offset, priv->shadow, val); + + for (i = 0; i < priv->n_latched_gpios; i++) + set(priv->latched_gpios->desc[i], + test_bit(latch * priv->n_latched_gpios + i, priv->shadow)); + + ndelay(priv->setup_duration_ns); + set(priv->clk_gpios->desc[latch], 1); + ndelay(priv->clock_duration_ns); + set(priv->clk_gpios->desc[latch], 0); +} + +static void gpio_latch_set(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct gpio_latch_priv *priv = gpiochip_get_data(gc); + unsigned long flags; + + spin_lock_irqsave(&priv->spinlock, flags); + + gpio_latch_set_unlocked(priv, gpiod_set_value, offset, val); + + spin_unlock_irqrestore(&priv->spinlock, flags); +} + +static void gpio_latch_set_can_sleep(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct gpio_latch_priv *priv = gpiochip_get_data(gc); + + mutex_lock(&priv->mutex); + + gpio_latch_set_unlocked(priv, gpiod_set_value_cansleep, offset, val); + + mutex_unlock(&priv->mutex); +} + +static bool gpio_latch_can_sleep(struct gpio_latch_priv *priv, unsigned int n_latches) +{ + int i; + + for (i = 0; i < n_latches; i++) + if (gpiod_cansleep(priv->clk_gpios->desc[i])) + return true; + + for (i = 0; i < priv->n_latched_gpios; i++) + if (gpiod_cansleep(priv->latched_gpios->desc[i])) + return true; + + return false; +} + +/* + * Some value which is still acceptable to delay in atomic context. + * If we need to go higher we might have to switch to usleep_range(), + * but that cannot ne used in atomic context and the driver would have + * to be adjusted to support that. + */ +#define DURATION_NS_MAX 5000 + +static int gpio_latch_probe(struct platform_device *pdev) +{ + struct gpio_latch_priv *priv; + unsigned int n_latches; + struct device_node *np = pdev->dev.of_node; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->clk_gpios = devm_gpiod_get_array(&pdev->dev, "clk", GPIOD_OUT_LOW); + if (IS_ERR(priv->clk_gpios)) + return PTR_ERR(priv->clk_gpios); + + priv->latched_gpios = devm_gpiod_get_array(&pdev->dev, "latched", GPIOD_OUT_LOW); + if (IS_ERR(priv->latched_gpios)) + return PTR_ERR(priv->latched_gpios); + + n_latches = priv->clk_gpios->ndescs; + priv->n_latched_gpios = priv->latched_gpios->ndescs; + + priv->shadow = devm_bitmap_zalloc(&pdev->dev, n_latches * priv->n_latched_gpios, + GFP_KERNEL); + if (!priv->shadow) + return -ENOMEM; + + if (gpio_latch_can_sleep(priv, n_latches)) { + priv->gc.can_sleep = true; + priv->gc.set = gpio_latch_set_can_sleep; + mutex_init(&priv->mutex); + } else { + priv->gc.can_sleep = false; + priv->gc.set = gpio_latch_set; + spin_lock_init(&priv->spinlock); + } + + of_property_read_u32(np, "setup-duration-ns", &priv->setup_duration_ns); + if (priv->setup_duration_ns > DURATION_NS_MAX) { + dev_warn(&pdev->dev, "setup-duration-ns too high, limit to %d\n", + DURATION_NS_MAX); + priv->setup_duration_ns = DURATION_NS_MAX; + } + + of_property_read_u32(np, "clock-duration-ns", &priv->clock_duration_ns); + if (priv->clock_duration_ns > DURATION_NS_MAX) { + dev_warn(&pdev->dev, "clock-duration-ns too high, limit to %d\n", + DURATION_NS_MAX); + priv->clock_duration_ns = DURATION_NS_MAX; + } + + priv->gc.get_direction = gpio_latch_get_direction; + priv->gc.ngpio = n_latches * priv->n_latched_gpios; + priv->gc.owner = THIS_MODULE; + priv->gc.base = -1; + priv->gc.parent = &pdev->dev; + + platform_set_drvdata(pdev, priv); + + return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv); +} + +static const struct of_device_id gpio_latch_ids[] = { + { + .compatible = "gpio-latch", + }, { + /* sentinel */ + } +}; +MODULE_DEVICE_TABLE(of, gpio_latch_ids); + +static struct platform_driver gpio_latch_driver = { + .driver = { + .name = "gpio-latch", + .of_match_table = gpio_latch_ids, + }, + .probe = gpio_latch_probe, +}; +module_platform_driver(gpio_latch_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); +MODULE_DESCRIPTION("GPIO latch driver"); -- 2.30.2 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v5 1/2] gpio: Add gpio latch driver 2022-10-07 11:46 ` [PATCH v5 1/2] gpio: Add gpio latch driver Sascha Hauer @ 2022-10-07 16:29 ` Serge Semin 2022-10-17 8:50 ` Linus Walleij 1 sibling, 0 replies; 8+ messages in thread From: Serge Semin @ 2022-10-07 16:29 UTC (permalink / raw) To: Sascha Hauer, Linus Walleij, Bartosz Golaszewski Cc: linux-gpio, devicetree, linux-kernel, kernel On Fri, Oct 07, 2022 at 01:46:46PM +0200, Sascha Hauer wrote: > This driver implements a GPIO multiplexer based on latches connected to > other GPIOs. A set of data GPIOs is connected to the data input of > multiple latches. The clock input of each latch is driven by another > set of GPIOs. With two 8-bit latches 10 GPIOs can be multiplexed into > 16 GPIOs. GPOs might be a better term as in fact the multiplexed pins > are output only. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Please find a tiny nitpick below. > --- > > Notes: > Changes since v4: > - Use correct ndelay instead of udelay > - Use #define for constant value > - drop unnecessary delay > > Changes since v3: > - Introduce delays between GPIO toggles as suggested by Serge Semin > > Changes since v2: > - Fix inconsistent licensing > - document locks > - use regular bit operations > - include linux/mod_devicetable.h rather than linux/of_device.h > - Put spinlock and mutex into a union to make clear that only one of them is used > - rename __gpio_latch_set to gpio_latch_set_unlocked > > Changes since v1: > - Use gpiod_set_value_cansleep when the underlying GPIOs might sleep > - Move MODULE_DEVICE_TABLE near to the end > > drivers/gpio/Kconfig | 6 ++ > drivers/gpio/Makefile | 1 + > drivers/gpio/gpio-latch.c | 220 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 227 insertions(+) > create mode 100644 drivers/gpio/gpio-latch.c > > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig > index 0642f579196f2..e4603810ec910 100644 > --- a/drivers/gpio/Kconfig > +++ b/drivers/gpio/Kconfig > @@ -1690,6 +1690,12 @@ config GPIO_AGGREGATOR > industrial control context, to be operated from userspace using > the GPIO chardev interface. > > +config GPIO_LATCH > + tristate "GPIO latch driver" > + help > + Say yes here to enable a driver for GPIO multiplexers based on latches > + connected to other GPIOs. > + > config GPIO_MOCKUP > tristate "GPIO Testing Driver" > select IRQ_SIM > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile > index a0985d30f51bb..310fa08decc69 100644 > --- a/drivers/gpio/Makefile > +++ b/drivers/gpio/Makefile > @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_IT87) += gpio-it87.o > obj-$(CONFIG_GPIO_IXP4XX) += gpio-ixp4xx.o > obj-$(CONFIG_GPIO_JANZ_TTL) += gpio-janz-ttl.o > obj-$(CONFIG_GPIO_KEMPLD) += gpio-kempld.o > +obj-$(CONFIG_GPIO_LATCH) += gpio-latch.o > obj-$(CONFIG_GPIO_LOGICVC) += gpio-logicvc.o > obj-$(CONFIG_GPIO_LOONGSON1) += gpio-loongson1.o > obj-$(CONFIG_GPIO_LOONGSON) += gpio-loongson.o > diff --git a/drivers/gpio/gpio-latch.c b/drivers/gpio/gpio-latch.c > new file mode 100644 > index 0000000000000..24a8237b712b4 > --- /dev/null > +++ b/drivers/gpio/gpio-latch.c > @@ -0,0 +1,220 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * GPIO latch driver > + * > + * Copyright (C) 2022 Sascha Hauer <s.hauer@pengutronix.de> > + * > + * This driver implements a GPIO (or better GPO as there is no input) > + * multiplexer based on latches like this: > + * > + * CLK0 ----------------------. ,--------. > + * CLK1 -------------------. `--------|> #0 | > + * | | | > + * OUT0 ----------------+--|-----------|D0 Q0|-----|< > + * OUT1 --------------+-|--|-----------|D1 Q1|-----|< > + * OUT2 ------------+-|-|--|-----------|D2 Q2|-----|< > + * OUT3 ----------+-|-|-|--|-----------|D3 Q3|-----|< > + * OUT4 --------+-|-|-|-|--|-----------|D4 Q4|-----|< > + * OUT5 ------+-|-|-|-|-|--|-----------|D5 Q5|-----|< > + * OUT6 ----+-|-|-|-|-|-|--|-----------|D6 Q6|-----|< > + * OUT7 --+-|-|-|-|-|-|-|--|-----------|D7 Q7|-----|< > + * | | | | | | | | | `--------' > + * | | | | | | | | | > + * | | | | | | | | | ,--------. > + * | | | | | | | | `-----------|> #1 | > + * | | | | | | | | | | > + * | | | | | | | `--------------|D0 Q0|-----|< > + * | | | | | | `----------------|D1 Q1|-----|< > + * | | | | | `------------------|D2 Q2|-----|< > + * | | | | `--------------------|D3 Q3|-----|< > + * | | | `----------------------|D4 Q4|-----|< > + * | | `------------------------|D5 Q5|-----|< > + * | `--------------------------|D6 Q6|-----|< > + * `----------------------------|D7 Q7|-----|< > + * `--------' > + * > + * The above is just an example. The actual number of number of latches and > + * the number of inputs per latch is derived from the number of GPIOs given > + * in the corresponding device tree properties. > + */ > + > +#include <linux/err.h> > +#include <linux/gpio/consumer.h> > +#include <linux/gpio/driver.h> > +#include <linux/module.h> > +#include <linux/mod_devicetable.h> > +#include <linux/platform_device.h> > +#include <linux/delay.h> > + > +#include "gpiolib.h" > + > +struct gpio_latch_priv { > + struct gpio_chip gc; > + struct gpio_descs *clk_gpios; > + struct gpio_descs *latched_gpios; > + int n_latched_gpios; > + unsigned int setup_duration_ns; > + unsigned int clock_duration_ns; > + unsigned long *shadow; > + /* > + * Depending on whether any of the underlying GPIOs may sleep we either > + * use a mutex or a spinlock to protect our shadow map. > + */ > + union { > + struct mutex mutex; /* protects @shadow */ > + spinlock_t spinlock; /* protects @shadow */ > + }; > +}; > + > +static int gpio_latch_get_direction(struct gpio_chip *gc, unsigned int offset) > +{ > + return GPIO_LINE_DIRECTION_OUT; > +} > + > +static void gpio_latch_set_unlocked(struct gpio_latch_priv *priv, > + void (*set)(struct gpio_desc *desc, int value), > + unsigned int offset, bool val) > +{ > + int latch = offset / priv->n_latched_gpios; > + int i; > + > + assign_bit(offset, priv->shadow, val); > + > + for (i = 0; i < priv->n_latched_gpios; i++) > + set(priv->latched_gpios->desc[i], > + test_bit(latch * priv->n_latched_gpios + i, priv->shadow)); > + > + ndelay(priv->setup_duration_ns); > + set(priv->clk_gpios->desc[latch], 1); > + ndelay(priv->clock_duration_ns); > + set(priv->clk_gpios->desc[latch], 0); > +} > + > +static void gpio_latch_set(struct gpio_chip *gc, unsigned int offset, int val) > +{ > + struct gpio_latch_priv *priv = gpiochip_get_data(gc); > + unsigned long flags; > + > + spin_lock_irqsave(&priv->spinlock, flags); > + > + gpio_latch_set_unlocked(priv, gpiod_set_value, offset, val); > + > + spin_unlock_irqrestore(&priv->spinlock, flags); > +} > + > +static void gpio_latch_set_can_sleep(struct gpio_chip *gc, unsigned int offset, int val) > +{ > + struct gpio_latch_priv *priv = gpiochip_get_data(gc); > + > + mutex_lock(&priv->mutex); > + > + gpio_latch_set_unlocked(priv, gpiod_set_value_cansleep, offset, val); > + > + mutex_unlock(&priv->mutex); > +} > + > +static bool gpio_latch_can_sleep(struct gpio_latch_priv *priv, unsigned int n_latches) > +{ > + int i; > + > + for (i = 0; i < n_latches; i++) > + if (gpiod_cansleep(priv->clk_gpios->desc[i])) > + return true; > + > + for (i = 0; i < priv->n_latched_gpios; i++) > + if (gpiod_cansleep(priv->latched_gpios->desc[i])) > + return true; > + > + return false; > +} > + > +/* > + * Some value which is still acceptable to delay in atomic context. > + * If we need to go higher we might have to switch to usleep_range(), > + * but that cannot ne used in atomic context and the driver would have > + * to be adjusted to support that. > + */ > +#define DURATION_NS_MAX 5000 As I mentioned in v4 it would be better to place this above the struct gpio_latch_priv declaration with the same comment. It's a common practice to collect the macros in the head of the C-files above any struct or forward declarations. But I guess @Linus or @Bartosz could do that after merging the patch in if they find it's worth to be done. -Sergey > + > +static int gpio_latch_probe(struct platform_device *pdev) > +{ > + struct gpio_latch_priv *priv; > + unsigned int n_latches; > + struct device_node *np = pdev->dev.of_node; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->clk_gpios = devm_gpiod_get_array(&pdev->dev, "clk", GPIOD_OUT_LOW); > + if (IS_ERR(priv->clk_gpios)) > + return PTR_ERR(priv->clk_gpios); > + > + priv->latched_gpios = devm_gpiod_get_array(&pdev->dev, "latched", GPIOD_OUT_LOW); > + if (IS_ERR(priv->latched_gpios)) > + return PTR_ERR(priv->latched_gpios); > + > + n_latches = priv->clk_gpios->ndescs; > + priv->n_latched_gpios = priv->latched_gpios->ndescs; > + > + priv->shadow = devm_bitmap_zalloc(&pdev->dev, n_latches * priv->n_latched_gpios, > + GFP_KERNEL); > + if (!priv->shadow) > + return -ENOMEM; > + > + if (gpio_latch_can_sleep(priv, n_latches)) { > + priv->gc.can_sleep = true; > + priv->gc.set = gpio_latch_set_can_sleep; > + mutex_init(&priv->mutex); > + } else { > + priv->gc.can_sleep = false; > + priv->gc.set = gpio_latch_set; > + spin_lock_init(&priv->spinlock); > + } > + > + of_property_read_u32(np, "setup-duration-ns", &priv->setup_duration_ns); > + if (priv->setup_duration_ns > DURATION_NS_MAX) { > + dev_warn(&pdev->dev, "setup-duration-ns too high, limit to %d\n", > + DURATION_NS_MAX); > + priv->setup_duration_ns = DURATION_NS_MAX; > + } > + > + of_property_read_u32(np, "clock-duration-ns", &priv->clock_duration_ns); > + if (priv->clock_duration_ns > DURATION_NS_MAX) { > + dev_warn(&pdev->dev, "clock-duration-ns too high, limit to %d\n", > + DURATION_NS_MAX); > + priv->clock_duration_ns = DURATION_NS_MAX; > + } > + > + priv->gc.get_direction = gpio_latch_get_direction; > + priv->gc.ngpio = n_latches * priv->n_latched_gpios; > + priv->gc.owner = THIS_MODULE; > + priv->gc.base = -1; > + priv->gc.parent = &pdev->dev; > + > + platform_set_drvdata(pdev, priv); > + > + return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv); > +} > + > +static const struct of_device_id gpio_latch_ids[] = { > + { > + .compatible = "gpio-latch", > + }, { > + /* sentinel */ > + } > +}; > +MODULE_DEVICE_TABLE(of, gpio_latch_ids); > + > +static struct platform_driver gpio_latch_driver = { > + .driver = { > + .name = "gpio-latch", > + .of_match_table = gpio_latch_ids, > + }, > + .probe = gpio_latch_probe, > +}; > +module_platform_driver(gpio_latch_driver); > + > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); > +MODULE_DESCRIPTION("GPIO latch driver"); > -- > 2.30.2 > ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v5 1/2] gpio: Add gpio latch driver 2022-10-07 11:46 ` [PATCH v5 1/2] gpio: Add gpio latch driver Sascha Hauer 2022-10-07 16:29 ` Serge Semin @ 2022-10-17 8:50 ` Linus Walleij 1 sibling, 0 replies; 8+ messages in thread From: Linus Walleij @ 2022-10-17 8:50 UTC (permalink / raw) To: Sascha Hauer Cc: linux-gpio, devicetree, linux-kernel, Bartosz Golaszewski, kernel, Serge Semin On Fri, Oct 7, 2022 at 1:47 PM Sascha Hauer <s.hauer@pengutronix.de> wrote: > This driver implements a GPIO multiplexer based on latches connected to > other GPIOs. A set of data GPIOs is connected to the data input of > multiple latches. The clock input of each latch is driven by another > set of GPIOs. With two 8-bit latches 10 GPIOs can be multiplexed into > 16 GPIOs. GPOs might be a better term as in fact the multiplexed pins > are output only. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> This looks fine to me! Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document 2022-10-07 11:46 [PATCH v5 0/2] gpio: Add gpio-latch driver Sascha Hauer 2022-10-07 11:46 ` [PATCH v5 1/2] gpio: Add gpio latch driver Sascha Hauer @ 2022-10-07 11:46 ` Sascha Hauer 2022-10-07 16:33 ` Serge Semin 2022-10-17 8:51 ` Linus Walleij 2022-10-25 9:39 ` [PATCH v5 0/2] gpio: Add gpio-latch driver Bartosz Golaszewski 2 siblings, 2 replies; 8+ messages in thread From: Sascha Hauer @ 2022-10-07 11:46 UTC (permalink / raw) To: linux-gpio Cc: devicetree, linux-kernel, Linus Walleij, Bartosz Golaszewski, kernel, Serge Semin, Sascha Hauer, Rob Herring This adds a binding for a GPIO multiplexer driver based on latches connected to other GPIOs. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Rob Herring <robh@kernel.org> --- Notes: Changes since v3: - Introduce delays between GPIO toggles as suggested by Serge Semin Changes since v1: - Add license to binding file .../devicetree/bindings/gpio/gpio-latch.yaml | 94 +++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/gpio-latch.yaml diff --git a/Documentation/devicetree/bindings/gpio/gpio-latch.yaml b/Documentation/devicetree/bindings/gpio/gpio-latch.yaml new file mode 100644 index 0000000000000..1ed82a2cebdaa --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-latch.yaml @@ -0,0 +1,94 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/gpio-latch.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: GPIO latch controller + +maintainers: + - Sascha Hauer <s.hauer@pengutronix.de> + +description: | + This binding describes a GPIO multiplexer based on latches connected to + other GPIOs, like this: + + CLK0 ----------------------. ,--------. + CLK1 -------------------. `--------|> #0 | + | | | + OUT0 ----------------+--|-----------|D0 Q0|-----|< + OUT1 --------------+-|--|-----------|D1 Q1|-----|< + OUT2 ------------+-|-|--|-----------|D2 Q2|-----|< + OUT3 ----------+-|-|-|--|-----------|D3 Q3|-----|< + OUT4 --------+-|-|-|-|--|-----------|D4 Q4|-----|< + OUT5 ------+-|-|-|-|-|--|-----------|D5 Q5|-----|< + OUT6 ----+-|-|-|-|-|-|--|-----------|D6 Q6|-----|< + OUT7 --+-|-|-|-|-|-|-|--|-----------|D7 Q7|-----|< + | | | | | | | | | `--------' + | | | | | | | | | + | | | | | | | | | ,--------. + | | | | | | | | `-----------|> #1 | + | | | | | | | | | | + | | | | | | | `--------------|D0 Q0|-----|< + | | | | | | `----------------|D1 Q1|-----|< + | | | | | `------------------|D2 Q2|-----|< + | | | | `--------------------|D3 Q3|-----|< + | | | `----------------------|D4 Q4|-----|< + | | `------------------------|D5 Q5|-----|< + | `--------------------------|D6 Q6|-----|< + `----------------------------|D7 Q7|-----|< + `--------' + + The number of clk-gpios and latched-gpios is not fixed. The actual number + of number of latches and the number of inputs per latch is derived from + the number of GPIOs given in the corresponding device tree properties. + +properties: + compatible: + const: gpio-latch + "#gpio-cells": + const: 2 + + clk-gpios: + description: Array of GPIOs to be used to clock a latch + + latched-gpios: + description: Array of GPIOs to be used as inputs per latch + + setup-duration-ns: + description: Delay in nanoseconds to wait after the latch inputs have been + set up + + clock-duration-ns: + description: Delay in nanoseconds to wait between clock output changes + + gpio-controller: true + + gpio-line-names: true + +required: + - compatible + - "#gpio-cells" + - gpio-controller + - clk-gpios + - latched-gpios + +additionalProperties: false + +examples: + - | + gpio-latch { + #gpio-cells = <2>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_di_do_leds>; + compatible = "gpio-latch"; + gpio-controller; + setup-duration-ns = <100>; + clock-duration-ns = <100>; + + clk-gpios = <&gpio3 7 0>, <&gpio3 8 0>; + latched-gpios = <&gpio3 21 0>, <&gpio3 22 0>, + <&gpio3 23 0>, <&gpio3 24 0>, + <&gpio3 25 0>, <&gpio3 26 0>, + <&gpio3 27 0>, <&gpio3 28 0>; + }; -- 2.30.2 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document 2022-10-07 11:46 ` [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document Sascha Hauer @ 2022-10-07 16:33 ` Serge Semin 2022-10-17 8:51 ` Linus Walleij 1 sibling, 0 replies; 8+ messages in thread From: Serge Semin @ 2022-10-07 16:33 UTC (permalink / raw) To: Sascha Hauer Cc: linux-gpio, devicetree, linux-kernel, Linus Walleij, Bartosz Golaszewski, kernel, Rob Herring On Fri, Oct 07, 2022 at 01:46:47PM +0200, Sascha Hauer wrote: > This adds a binding for a GPIO multiplexer driver based on latches > connected to other GPIOs. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Just a note. In accordance with [1] the DT-bindings patches should come in the series before the code implementing the bindings. [1] Documentation/devicetree/bindings/submitting-patches.rst, unit I.5). -Sergey > --- > > Notes: > Changes since v3: > - Introduce delays between GPIO toggles as suggested by Serge Semin > > Changes since v1: > - Add license to binding file > > .../devicetree/bindings/gpio/gpio-latch.yaml | 94 +++++++++++++++++++ > 1 file changed, 94 insertions(+) > create mode 100644 Documentation/devicetree/bindings/gpio/gpio-latch.yaml > > diff --git a/Documentation/devicetree/bindings/gpio/gpio-latch.yaml b/Documentation/devicetree/bindings/gpio/gpio-latch.yaml > new file mode 100644 > index 0000000000000..1ed82a2cebdaa > --- /dev/null > +++ b/Documentation/devicetree/bindings/gpio/gpio-latch.yaml > @@ -0,0 +1,94 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/gpio/gpio-latch.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: GPIO latch controller > + > +maintainers: > + - Sascha Hauer <s.hauer@pengutronix.de> > + > +description: | > + This binding describes a GPIO multiplexer based on latches connected to > + other GPIOs, like this: > + > + CLK0 ----------------------. ,--------. > + CLK1 -------------------. `--------|> #0 | > + | | | > + OUT0 ----------------+--|-----------|D0 Q0|-----|< > + OUT1 --------------+-|--|-----------|D1 Q1|-----|< > + OUT2 ------------+-|-|--|-----------|D2 Q2|-----|< > + OUT3 ----------+-|-|-|--|-----------|D3 Q3|-----|< > + OUT4 --------+-|-|-|-|--|-----------|D4 Q4|-----|< > + OUT5 ------+-|-|-|-|-|--|-----------|D5 Q5|-----|< > + OUT6 ----+-|-|-|-|-|-|--|-----------|D6 Q6|-----|< > + OUT7 --+-|-|-|-|-|-|-|--|-----------|D7 Q7|-----|< > + | | | | | | | | | `--------' > + | | | | | | | | | > + | | | | | | | | | ,--------. > + | | | | | | | | `-----------|> #1 | > + | | | | | | | | | | > + | | | | | | | `--------------|D0 Q0|-----|< > + | | | | | | `----------------|D1 Q1|-----|< > + | | | | | `------------------|D2 Q2|-----|< > + | | | | `--------------------|D3 Q3|-----|< > + | | | `----------------------|D4 Q4|-----|< > + | | `------------------------|D5 Q5|-----|< > + | `--------------------------|D6 Q6|-----|< > + `----------------------------|D7 Q7|-----|< > + `--------' > + > + The number of clk-gpios and latched-gpios is not fixed. The actual number > + of number of latches and the number of inputs per latch is derived from > + the number of GPIOs given in the corresponding device tree properties. > + > +properties: > + compatible: > + const: gpio-latch > + "#gpio-cells": > + const: 2 > + > + clk-gpios: > + description: Array of GPIOs to be used to clock a latch > + > + latched-gpios: > + description: Array of GPIOs to be used as inputs per latch > + > + setup-duration-ns: > + description: Delay in nanoseconds to wait after the latch inputs have been > + set up > + > + clock-duration-ns: > + description: Delay in nanoseconds to wait between clock output changes > + > + gpio-controller: true > + > + gpio-line-names: true > + > +required: > + - compatible > + - "#gpio-cells" > + - gpio-controller > + - clk-gpios > + - latched-gpios > + > +additionalProperties: false > + > +examples: > + - | > + gpio-latch { > + #gpio-cells = <2>; > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_di_do_leds>; > + compatible = "gpio-latch"; > + gpio-controller; > + setup-duration-ns = <100>; > + clock-duration-ns = <100>; > + > + clk-gpios = <&gpio3 7 0>, <&gpio3 8 0>; > + latched-gpios = <&gpio3 21 0>, <&gpio3 22 0>, > + <&gpio3 23 0>, <&gpio3 24 0>, > + <&gpio3 25 0>, <&gpio3 26 0>, > + <&gpio3 27 0>, <&gpio3 28 0>; > + }; > -- > 2.30.2 > ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document 2022-10-07 11:46 ` [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document Sascha Hauer 2022-10-07 16:33 ` Serge Semin @ 2022-10-17 8:51 ` Linus Walleij 1 sibling, 0 replies; 8+ messages in thread From: Linus Walleij @ 2022-10-17 8:51 UTC (permalink / raw) To: Sascha Hauer Cc: linux-gpio, devicetree, linux-kernel, Bartosz Golaszewski, kernel, Serge Semin, Rob Herring On Fri, Oct 7, 2022 at 1:47 PM Sascha Hauer <s.hauer@pengutronix.de> wrote: > This adds a binding for a GPIO multiplexer driver based on latches > connected to other GPIOs. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v5 0/2] gpio: Add gpio-latch driver 2022-10-07 11:46 [PATCH v5 0/2] gpio: Add gpio-latch driver Sascha Hauer 2022-10-07 11:46 ` [PATCH v5 1/2] gpio: Add gpio latch driver Sascha Hauer 2022-10-07 11:46 ` [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document Sascha Hauer @ 2022-10-25 9:39 ` Bartosz Golaszewski 2 siblings, 0 replies; 8+ messages in thread From: Bartosz Golaszewski @ 2022-10-25 9:39 UTC (permalink / raw) To: Sascha Hauer Cc: linux-gpio, devicetree, linux-kernel, Linus Walleij, kernel, Serge Semin On Fri, Oct 7, 2022 at 1:47 PM Sascha Hauer <s.hauer@pengutronix.de> wrote: > > This series includes the changes requested by Serge Semin for v4. > > Sascha > > Sascha Hauer (2): > gpio: Add gpio latch driver > dt-bindings: gpio: Add gpio-latch binding document > > .../devicetree/bindings/gpio/gpio-latch.yaml | 94 ++++++++ > drivers/gpio/Kconfig | 6 + > drivers/gpio/Makefile | 1 + > drivers/gpio/gpio-latch.c | 220 ++++++++++++++++++ > 4 files changed, 321 insertions(+) > create mode 100644 Documentation/devicetree/bindings/gpio/gpio-latch.yaml > create mode 100644 drivers/gpio/gpio-latch.c > > -- > 2.30.2 > I reversed the order of the patches, fixed the strange formatting of struct of_device_id and queued the series. Bartosz ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2022-10-25 9:41 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-10-07 11:46 [PATCH v5 0/2] gpio: Add gpio-latch driver Sascha Hauer 2022-10-07 11:46 ` [PATCH v5 1/2] gpio: Add gpio latch driver Sascha Hauer 2022-10-07 16:29 ` Serge Semin 2022-10-17 8:50 ` Linus Walleij 2022-10-07 11:46 ` [PATCH v5 2/2] dt-bindings: gpio: Add gpio-latch binding document Sascha Hauer 2022-10-07 16:33 ` Serge Semin 2022-10-17 8:51 ` Linus Walleij 2022-10-25 9:39 ` [PATCH v5 0/2] gpio: Add gpio-latch driver Bartosz Golaszewski
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