From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i6Ens-0002XD-Fp for barebox@lists.infradead.org; Fri, 06 Sep 2019 14:01:34 +0000 From: Ahmad Fatoum Date: Fri, 6 Sep 2019 16:01:27 +0200 Message-Id: <20190906140127.17396-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] gpio: add driver for SN74273 output expander To: barebox@lists.infradead.org Cc: Ahmad Fatoum The SN74273 is an octal D-Type Flip-Flop. When used as an output expander, N existing output signals can be turned into (N-8)*8 outputs using N-8 chips. Add driver to facilitate this. Signed-off-by: Sascha Hauer Signed-off-by: Ahmad Fatoum --- .../bindings/gpio/ti,74273-gpio.rst | 34 ++++ drivers/gpio/Kconfig | 5 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-74273.c | 183 ++++++++++++++++++ 4 files changed, 223 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/ti,74273-gpio.rst create mode 100644 drivers/gpio/gpio-74273.c diff --git a/Documentation/devicetree/bindings/gpio/ti,74273-gpio.rst b/Documentation/devicetree/bindings/gpio/ti,74273-gpio.rst new file mode 100644 index 000000000000..6fc001451c2f --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/ti,74273-gpio.rst @@ -0,0 +1,34 @@ +74273 output expander driver +============================ + +Required properties: + +- ``compatible``: Should be ``"ti,74273-gpio"`` +- ``gpio-controller``: Marks the device node as a gpio controller. +- ``#gpio-cells``: Should be two. The first cell is the pin number and + the second cell is used to specify the GPIO polarity: + ``0`` = Active High, + ``1`` = Active Low. +- ``clk-gpios``: One GPIO per connected 74273 chip +- ``data-gpios``: Eight GPIOs per connected 74273 (D-Pins) + +Optional properties: + +- ``ti,clk-pulse-width-ns``: minimal width of clock pulse for each chip. + If unspecified, ``<20>`` is used as default. + +Example:: + + sn74273-gpio { + compatible = "ti,74273-gpio"; + gpio-controller; + #gpio-cells = <2>; + + clk-gpios = <&gpio3 7 GPIO_ACTIVE_HIGH>, <&gpio3 8 GPIO_ACTIVE_HIGH>; + ti,clk-pulse-width-ns = <30>, <30>; + data-gpios = <&gpio3 21 GPIO_ACTIVE_LOW>, <&gpio3 22 GPIO_ACTIVE_LOW>, + <&gpio3 23 GPIO_ACTIVE_LOW>, <&gpio3 24 GPIO_ACTIVE_LOW>, + <&gpio3 25 GPIO_ACTIVE_LOW>, <&gpio3 26 GPIO_ACTIVE_LOW>, + <&gpio3 27 GPIO_ACTIVE_LOW>, <&gpio3 28 GPIO_ACTIVE_LOW>; + }; + diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 7a1503198b49..dd6e6dd0c1c8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -145,6 +145,11 @@ config GPIO_SX150X Say Y here to build support for the Semtec Sx150x I2C GPIO expander chip. +config GPIO_74273 + bool "SN74273 output ports" + help + Say Y here to include a driver for the SN74273 as output expander + config GPIO_LIBFTDI1 bool "libftdi1 driver" depends on SANDBOX diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 990df01788bc..ba818c7b94c0 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -21,3 +21,4 @@ obj-$(CONFIG_GPIO_TEGRA) += gpio-tegra.o obj-$(CONFIG_GPIO_DESIGNWARE) += gpio-dw.o obj-$(CONFIG_GPIO_SX150X) += gpio-sx150x.o obj-$(CONFIG_GPIO_VF610) += gpio-vf610.o +obj-$(CONFIG_GPIO_74273) += gpio-74273.o diff --git a/drivers/gpio/gpio-74273.c b/drivers/gpio/gpio-74273.c new file mode 100644 index 000000000000..873f523c1b0b --- /dev/null +++ b/drivers/gpio/gpio-74273.c @@ -0,0 +1,183 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2017 Sascha Hauer, Pengutronix + * Copyright (c) 2019 Ahmad Fatoum, Pengutronix + */ + +#include +#include +#include +#include +#include +#include +#include + +#define DEFAULT_DELAY_NS 20 + +struct clk_gpio { + int desc; + u32 delay_ns; +}; + +struct sn74273 { + struct gpio_chip chip; + struct clk_gpio *clk_gpios; + int *data_gpios; + u8 *shadow; + unsigned n_ports; + unsigned n_pins; +}; + +static inline struct sn74273 *to_sn74273(struct gpio_chip *chip) +{ + return container_of(chip, struct sn74273, chip); +} + +static void sn74273_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value) +{ + struct sn74273 *sn74273 = to_sn74273(chip); + unsigned port = gpio / 8; + unsigned pin = gpio % 8; + int i, j; + u8 val; + + val = sn74273->shadow[port]; + if (value) + val |= 1 << pin; + else + val &= ~(1 << pin); + sn74273->shadow[port] = val; + + for (i = 0; i < sn74273->n_ports; i++) { + for (j = 0; j < sn74273->n_pins; j++) { + gpio_set_active(sn74273->data_gpios[j], + sn74273->shadow[i] & (1 << j)); + } + + ndelay(sn74273->clk_gpios[i].delay_ns); + gpio_set_active(sn74273->clk_gpios[i].desc, 1); + ndelay(sn74273->clk_gpios[i].delay_ns); + gpio_set_active(sn74273->clk_gpios[i].desc, 0); + } +} + +static int sn74273_gpio_get_value(struct gpio_chip *chip, unsigned gpio) +{ + struct sn74273 *sn74273 = to_sn74273(chip); + unsigned port = gpio / 8; + unsigned pin = gpio % 8; + + return sn74273->shadow[port] & pin; +} + +static int sn74273_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + sn74273_gpio_set_value(chip, offset, value); + return 0; +} + +static int sn74273_gpio_get_direction(struct gpio_chip *chip, unsigned offset) +{ + return GPIOF_DIR_OUT; +} + +static struct gpio_ops sn74273_gpio_ops = { + .get = sn74273_gpio_get_value, + .set = sn74273_gpio_set_value, + .direction_output = sn74273_gpio_direction_output, + .get_direction = sn74273_gpio_get_direction, +}; + +static int sn74273_gpio_probe(struct device_d *dev) +{ + struct device_node *np = dev->device_node; + enum of_gpio_flags flags; + struct sn74273 *sn74273; + int i, ret; + + sn74273 = xzalloc(sizeof(*sn74273)); + + sn74273->n_ports = of_gpio_named_count(np, "clk-gpios"); + if (sn74273->n_ports < 0) { + dev_err(dev, "invalid or missing clk-gpios\n"); + return -EINVAL; + } + + sn74273->n_pins = of_gpio_named_count(np, "data-gpios"); + if (sn74273->n_pins < 0) { + dev_err(dev, "invalid or missing data-gpios\n"); + return -EINVAL; + } + + sn74273->chip.base = -1; + sn74273->chip.ngpio = sn74273->n_ports * sn74273->n_pins; + sn74273->chip.dev = dev; + sn74273->chip.ops = &sn74273_gpio_ops; + + sn74273->clk_gpios = xzalloc(sizeof(struct clk_gpio) * sn74273->n_ports); + sn74273->data_gpios = xzalloc(sizeof(int) * sn74273->n_pins); + + for (i = 0; i < sn74273->n_ports; i++) { + struct clk_gpio *clk_gpio = &sn74273->clk_gpios[i]; + clk_gpio->desc = of_get_named_gpio_flags(np, "clk-gpios", + i, &flags); + ret = gpio_request_one(clk_gpio->desc, + flags & OF_GPIO_ACTIVE_LOW ? GPIOF_ACTIVE_LOW : 0, + dev_name(dev)); + if (ret) { + if (ret != -EPROBE_DEFER) + dev_err(dev, "Cannot request gpio %d: %s\n", clk_gpio->desc, + strerror(-ret)); + return ret; + } + + gpio_direction_output(clk_gpio->desc, 0); + + clk_gpio->delay_ns = DEFAULT_DELAY_NS; + of_property_read_u32_index(np, "ti,clk-pulse-width-ns", + i, &clk_gpio->delay_ns); + } + + for (i = 0; i < sn74273->n_pins; i++) { + sn74273->data_gpios[i] = of_get_named_gpio_flags(np, "data-gpios", + i, &flags); + ret = gpio_request_one(sn74273->data_gpios[i], + flags & OF_GPIO_ACTIVE_LOW ? GPIOF_ACTIVE_LOW : 0, + dev_name(dev)); + if (ret) { + if (ret != -EPROBE_DEFER) + dev_err(dev, "Cannot request gpio %d: %s\n", sn74273->data_gpios[i], + strerror(-ret)); + return ret; + } + + gpio_direction_output(sn74273->data_gpios[i], 0); + } + + sn74273->shadow = xzalloc(DIV_ROUND_UP(sn74273->n_pins, 8) * sn74273->n_ports); + + ret = gpiochip_add(&sn74273->chip); + if (ret) + dev_err(dev, "cannot add 74273 GPIO chip: %s\n", strerror(-ret)); + + return ret; +} + +static const struct of_device_id of_sn74273_gpio_leds_match[] = { + { .compatible = "ti,74273-gpio" }, + { /* sentinel */ }, +}; + +static struct driver_d sn74273_gpio_driver = { + .name = "74273-gpio", + .probe = sn74273_gpio_probe, + .of_compatible = DRV_OF_COMPAT(of_sn74273_gpio_leds_match), +}; + +static int sn74273_gpio_add(void) +{ + platform_driver_register(&sn74273_gpio_driver); + return 0; +} +postcore_initcall(sn74273_gpio_add); -- 2.23.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox