This commit adds support for the MAX7320 (and clones) gpio expander.

Signed-off-by: Hannes Schmelzer hannes.schmelzer@br-automation.com

---

doc/device-tree-bindings/gpio/gpio-max7320.txt | 36 ++++++++ drivers/gpio/Kconfig | 8 ++ drivers/gpio/Makefile | 1 + drivers/gpio/max7320_gpio.c | 113 +++++++++++++++++++++++++ 4 files changed, 158 insertions(+) create mode 100644 doc/device-tree-bindings/gpio/gpio-max7320.txt create mode 100644 drivers/gpio/max7320_gpio.c

diff --git a/doc/device-tree-bindings/gpio/gpio-max7320.txt b/doc/device-tree-bindings/gpio/gpio-max7320.txt new file mode 100644 index 0000000..87b703b --- /dev/null +++ b/doc/device-tree-bindings/gpio/gpio-max7320.txt @@ -0,0 +1,36 @@ +* MAX7320 I/O expanders + +The original maxim 7320 i/o expander offers 8 bit push/pull outputs. +There exists some clones which offers 16 bit. + +Required Properties: + + - compatible: should be one of the following. + - "maxim,max7320" + + - reg: I2C slave address. + + - gpio-controller: Marks the device node as a gpio controller. + - #gpio-cells: Should be 2. The first cell is the GPIO number and the second + cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. Only the + GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported. + +Optional Properties: + + - ngpios: tell the driver how many gpios the device offers. + if the property is omitted, 8bit (original maxim) is assumed. + +Please refer to gpio.txt in this directory for details of the common GPIO +bindings used by client devices. + +Example: MAX7320 I/O expander node + + ledgpio: max7320@5d { + status = "okay"; + compatible = "maxim,max7320"; + reg = <0x5d>; + #gpio-cells = <2>; + gpio-controller; + ngpios = <16>; + }; + diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index e37ac9f..3aafbe3 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -513,4 +513,12 @@ config NOMADIK_GPIO into a number of banks each with 32 GPIOs. The GPIOs for a device are defined in the device tree with one node for each bank.

+config MAX7320_GPIO + bool "MAX7320 I2C GPIO Expander driver" + depends on DM_GPIO && DM_I2C + help + Support for MAX7320 I2C 8/16-bit GPIO expander. + original maxim device has 8 push/pull outputs, + some clones offers 16bit. + endmenu diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 58f4704..f59ea4a 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -69,3 +69,4 @@ obj-$(CONFIG_MSCC_SGPIO) += mscc_sgpio.o obj-$(CONFIG_NX_GPIO) += nx_gpio.o obj-$(CONFIG_SIFIVE_GPIO) += sifive-gpio.o obj-$(CONFIG_NOMADIK_GPIO) += nmk_gpio.o +obj-$(CONFIG_MAX7320_GPIO) += max7320_gpio.o diff --git a/drivers/gpio/max7320_gpio.c b/drivers/gpio/max7320_gpio.c new file mode 100644 index 0000000..647aed9 --- /dev/null +++ b/drivers/gpio/max7320_gpio.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * max7320 I2C GPIO EXPANDER DRIVER + * + * Copyright (C) 2021 Hannes Schmelzer oe5hpm@oevsv.at + * B&R Industrial Automation GmbH - http://www.br-automation.com + * + */ + +#include <common.h> +#include <dm.h> +#include <i2c.h> +#include <asm-generic/gpio.h> +#include <linux/bitops.h> + +struct max7320_chip { + u32 outreg; +}; + +static int max7320_direction_output(struct udevice *dev, + unsigned int offset, int value) +{ + struct max7320_chip *plat = dev_get_plat(dev); + struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); + struct dm_i2c_chip *chip = dev_get_parent_plat(dev); + + int ret; + + if (value) + plat->outreg |= BIT(offset); + else + plat->outreg &= ~BIT(offset); + + ret = dm_i2c_write(dev, + plat->outreg & 0xff, + (uint8_t *)&plat->outreg + 1, + uc_priv->gpio_count > 8 ? 1 : 0); + if (ret) + printf("%s i2c write failed to addr %x\n", __func__, + chip->chip_addr); + + return ret; +} + +static int max7320_get_value(struct udevice *dev, unsigned int offset) +{ + struct max7320_chip *plat = dev_get_plat(dev); + + return (plat->outreg >> offset) & 0x1; +} + +static int max7320_set_value(struct udevice *dev, unsigned int offset, + int value) +{ + return max7320_direction_output(dev, offset, value); +} + +static int max7320_get_function(struct udevice *dev, unsigned int offset) +{ + return GPIOF_OUTPUT; +} + +static int max7320_ofdata_plat(struct udevice *dev) +{ + struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); + + uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", 8); + if (uc_priv->gpio_count > 16) { + printf("%s: max7320 doesn't support more than 16 gpios!", + __func__); + return -EINVAL; + } + + uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), + "gpio-bank-name", NULL); + if (!uc_priv->bank_name) + uc_priv->bank_name = fdt_get_name(gd->fdt_blob, + dev_of_offset(dev), NULL); + + return 0; +} + +static int max7320_gpio_probe(struct udevice *dev) +{ + struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); + + debug("%s GPIO controller with %d gpios probed\n", + uc_priv->bank_name, uc_priv->gpio_count); + + return 0; +} + +static const struct dm_gpio_ops max7320_gpio_ops = { + .direction_output = max7320_direction_output, + .set_value = max7320_set_value, + .get_value = max7320_get_value, + .get_function = max7320_get_function, +}; + +static const struct udevice_id max7320_gpio_ids[] = { + { .compatible = "maxim,max7320" }, + { } +}; + +U_BOOT_DRIVER(gpio_max7320) = { + .name = "gpio_max7320", + .id = UCLASS_GPIO, + .ops = &max7320_gpio_ops, + .of_match = max7320_gpio_ids, + .of_to_plat = max7320_ofdata_plat, + .probe = max7320_gpio_probe, + .plat_auto = sizeof(struct max7320_chip), +};