diff mbox series

[v10,2/6] gpio: Add Delta TN48M CPLD GPIO driver

Message ID 20220131133049.77780-3-robert.marko@sartura.hr
State Accepted
Commit b3dcb5de62092406bea6d5d03e32824d823fcd39
Headers show
Series Add Delta TN48M CPLD support | expand

Commit Message

Robert Marko Jan. 31, 2022, 1:30 p.m. UTC
Delta TN48M switch has an onboard Lattice CPLD that is used as a GPIO
expander.

The CPLD provides 12 pins in total on the TN48M, but on more advanced
switch models it provides up to 192 pins, so the driver is extendable
to support more switches.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
Changes in v10:
* Rebase onto 5.17-rc1

Changes in v9:
* Use {} instead of {0} for initialising the regmap config per Andys
comment
* Fix spelling mistake in KConfig

Changes in v8:
* No need to assing NULL to gpio_config per Andys comment

Changes in v7:
* Change compatibles, reduce their number
* Rework the driver to be easily extendible to support more devices
* Use match data to populate configuration
* Drop reviews and ACK-s as the driver changed

Changes in v6:
* Drop unused header
* Return the return value of device_property_read_u32()
instead of a hardcoded return

Changes in v2:
* Rewrite to use simple I2C MFD and GPIO regmap
* Drop DT bindings for pin numbering
---
 drivers/gpio/Kconfig      |  12 +++++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/gpio-tn48m.c | 100 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 drivers/gpio/gpio-tn48m.c

Comments

Bartosz Golaszewski Feb. 8, 2022, 9:18 a.m. UTC | #1
On Mon, Jan 31, 2022 at 2:30 PM Robert Marko <robert.marko@sartura.hr> wrote:
>
> Delta TN48M switch has an onboard Lattice CPLD that is used as a GPIO
> expander.
>
> The CPLD provides 12 pins in total on the TN48M, but on more advanced
> switch models it provides up to 192 pins, so the driver is extendable
> to support more switches.
>
> Signed-off-by: Robert Marko <robert.marko@sartura.hr>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Reviewed-by: Michael Walle <michael@walle.cc>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> Changes in v10:
> * Rebase onto 5.17-rc1
>
> Changes in v9:
> * Use {} instead of {0} for initialising the regmap config per Andys
> comment
> * Fix spelling mistake in KConfig
>
> Changes in v8:
> * No need to assing NULL to gpio_config per Andys comment
>
> Changes in v7:
> * Change compatibles, reduce their number
> * Rework the driver to be easily extendible to support more devices
> * Use match data to populate configuration
> * Drop reviews and ACK-s as the driver changed
>
> Changes in v6:
> * Drop unused header
> * Return the return value of device_property_read_u32()
> instead of a hardcoded return
>
> Changes in v2:
> * Rewrite to use simple I2C MFD and GPIO regmap
> * Drop DT bindings for pin numbering
> ---
>  drivers/gpio/Kconfig      |  12 +++++
>  drivers/gpio/Makefile     |   1 +
>  drivers/gpio/gpio-tn48m.c | 100 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 113 insertions(+)
>  create mode 100644 drivers/gpio/gpio-tn48m.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 1c211b4c63be..c822cf6146cf 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1346,6 +1346,18 @@ config GPIO_TIMBERDALE
>         help
>         Add support for the GPIO IP in the timberdale FPGA.
>
> +config GPIO_TN48M_CPLD
> +       tristate "Delta Networks TN48M switch CPLD GPIO driver"
> +       depends on MFD_TN48M_CPLD
> +       select GPIO_REGMAP
> +       help
> +         This enables support for the GPIOs found on the Delta
> +         Networks TN48M switch Lattice CPLD. It provides 12 pins in total,
> +         they are input-only or output-only type.
> +
> +         This driver can also be built as a module. If so, the
> +         module will be called gpio-tn48m.
> +
>  config GPIO_TPS65086
>         tristate "TI TPS65086 GPO"
>         depends on MFD_TPS65086
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index edbaa3cb343c..3b68a9808154 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -148,6 +148,7 @@ obj-$(CONFIG_GPIO_TEGRA186)         += gpio-tegra186.o
>  obj-$(CONFIG_GPIO_TEGRA)               += gpio-tegra.o
>  obj-$(CONFIG_GPIO_THUNDERX)            += gpio-thunderx.o
>  obj-$(CONFIG_GPIO_TIMBERDALE)          += gpio-timberdale.o
> +obj-$(CONFIG_GPIO_TN48M_CPLD)          += gpio-tn48m.o
>  obj-$(CONFIG_GPIO_TPIC2810)            += gpio-tpic2810.o
>  obj-$(CONFIG_GPIO_TPS65086)            += gpio-tps65086.o
>  obj-$(CONFIG_GPIO_TPS65218)            += gpio-tps65218.o
> diff --git a/drivers/gpio/gpio-tn48m.c b/drivers/gpio/gpio-tn48m.c
> new file mode 100644
> index 000000000000..cd4a80b22794
> --- /dev/null
> +++ b/drivers/gpio/gpio-tn48m.c
> @@ -0,0 +1,100 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Delta TN48M CPLD GPIO driver
> + *
> + * Copyright (C) 2021 Sartura Ltd.
> + *
> + * Author: Robert Marko <robert.marko@sartura.hr>
> + */
> +
> +#include <linux/device.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/gpio/regmap.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +enum tn48m_gpio_type {
> +       TN48M_GP0 = 1,
> +       TN48M_GPI,
> +};
> +
> +struct tn48m_gpio_config {
> +       int ngpio;
> +       int ngpio_per_reg;
> +       enum tn48m_gpio_type type;
> +};
> +
> +static const struct tn48m_gpio_config tn48m_gpo_config = {
> +       .ngpio = 4,
> +       .ngpio_per_reg = 4,
> +       .type = TN48M_GP0,
> +};
> +
> +static const struct tn48m_gpio_config tn48m_gpi_config = {
> +       .ngpio = 4,
> +       .ngpio_per_reg = 4,
> +       .type = TN48M_GPI,
> +};
> +
> +static int tn48m_gpio_probe(struct platform_device *pdev)
> +{
> +       const struct tn48m_gpio_config *gpio_config;
> +       struct gpio_regmap_config config = {};
> +       struct regmap *regmap;
> +       u32 base;
> +       int ret;
> +
> +       if (!pdev->dev.parent)
> +               return -ENODEV;
> +
> +       gpio_config = device_get_match_data(&pdev->dev);
> +       if (!gpio_config)
> +               return -ENODEV;
> +
> +       ret = device_property_read_u32(&pdev->dev, "reg", &base);
> +       if (ret)
> +               return ret;
> +
> +       regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +       if (!regmap)
> +               return -ENODEV;
> +
> +       config.regmap = regmap;
> +       config.parent = &pdev->dev;
> +       config.ngpio = gpio_config->ngpio;
> +       config.ngpio_per_reg = gpio_config->ngpio_per_reg;
> +       switch (gpio_config->type) {
> +       case TN48M_GP0:
> +               config.reg_set_base = base;
> +               break;
> +       case TN48M_GPI:
> +               config.reg_dat_base = base;
> +               break;
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
> +}
> +
> +static const struct of_device_id tn48m_gpio_of_match[] = {
> +       { .compatible = "delta,tn48m-gpo", .data = &tn48m_gpo_config },
> +       { .compatible = "delta,tn48m-gpi", .data = &tn48m_gpi_config },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, tn48m_gpio_of_match);
> +
> +static struct platform_driver tn48m_gpio_driver = {
> +       .driver = {
> +               .name = "delta-tn48m-gpio",
> +               .of_match_table = tn48m_gpio_of_match,
> +       },
> +       .probe = tn48m_gpio_probe,
> +};
> +module_platform_driver(tn48m_gpio_driver);
> +
> +MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
> +MODULE_DESCRIPTION("Delta TN48M CPLD GPIO driver");
> +MODULE_LICENSE("GPL");
> --
> 2.34.1
>

Small and clean, I love it.

Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
diff mbox series

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 1c211b4c63be..c822cf6146cf 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1346,6 +1346,18 @@  config GPIO_TIMBERDALE
 	help
 	Add support for the GPIO IP in the timberdale FPGA.
 
+config GPIO_TN48M_CPLD
+	tristate "Delta Networks TN48M switch CPLD GPIO driver"
+	depends on MFD_TN48M_CPLD
+	select GPIO_REGMAP
+	help
+	  This enables support for the GPIOs found on the Delta
+	  Networks TN48M switch Lattice CPLD. It provides 12 pins in total,
+	  they are input-only or output-only type.
+
+	  This driver can also be built as a module. If so, the
+	  module will be called gpio-tn48m.
+
 config GPIO_TPS65086
 	tristate "TI TPS65086 GPO"
 	depends on MFD_TPS65086
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index edbaa3cb343c..3b68a9808154 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -148,6 +148,7 @@  obj-$(CONFIG_GPIO_TEGRA186)		+= gpio-tegra186.o
 obj-$(CONFIG_GPIO_TEGRA)		+= gpio-tegra.o
 obj-$(CONFIG_GPIO_THUNDERX)		+= gpio-thunderx.o
 obj-$(CONFIG_GPIO_TIMBERDALE)		+= gpio-timberdale.o
+obj-$(CONFIG_GPIO_TN48M_CPLD)		+= gpio-tn48m.o
 obj-$(CONFIG_GPIO_TPIC2810)		+= gpio-tpic2810.o
 obj-$(CONFIG_GPIO_TPS65086)		+= gpio-tps65086.o
 obj-$(CONFIG_GPIO_TPS65218)		+= gpio-tps65218.o
diff --git a/drivers/gpio/gpio-tn48m.c b/drivers/gpio/gpio-tn48m.c
new file mode 100644
index 000000000000..cd4a80b22794
--- /dev/null
+++ b/drivers/gpio/gpio-tn48m.c
@@ -0,0 +1,100 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Delta TN48M CPLD GPIO driver
+ *
+ * Copyright (C) 2021 Sartura Ltd.
+ *
+ * Author: Robert Marko <robert.marko@sartura.hr>
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+enum tn48m_gpio_type {
+	TN48M_GP0 = 1,
+	TN48M_GPI,
+};
+
+struct tn48m_gpio_config {
+	int ngpio;
+	int ngpio_per_reg;
+	enum tn48m_gpio_type type;
+};
+
+static const struct tn48m_gpio_config tn48m_gpo_config = {
+	.ngpio = 4,
+	.ngpio_per_reg = 4,
+	.type = TN48M_GP0,
+};
+
+static const struct tn48m_gpio_config tn48m_gpi_config = {
+	.ngpio = 4,
+	.ngpio_per_reg = 4,
+	.type = TN48M_GPI,
+};
+
+static int tn48m_gpio_probe(struct platform_device *pdev)
+{
+	const struct tn48m_gpio_config *gpio_config;
+	struct gpio_regmap_config config = {};
+	struct regmap *regmap;
+	u32 base;
+	int ret;
+
+	if (!pdev->dev.parent)
+		return -ENODEV;
+
+	gpio_config = device_get_match_data(&pdev->dev);
+	if (!gpio_config)
+		return -ENODEV;
+
+	ret = device_property_read_u32(&pdev->dev, "reg", &base);
+	if (ret)
+		return ret;
+
+	regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!regmap)
+		return -ENODEV;
+
+	config.regmap = regmap;
+	config.parent = &pdev->dev;
+	config.ngpio = gpio_config->ngpio;
+	config.ngpio_per_reg = gpio_config->ngpio_per_reg;
+	switch (gpio_config->type) {
+	case TN48M_GP0:
+		config.reg_set_base = base;
+		break;
+	case TN48M_GPI:
+		config.reg_dat_base = base;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
+}
+
+static const struct of_device_id tn48m_gpio_of_match[] = {
+	{ .compatible = "delta,tn48m-gpo", .data = &tn48m_gpo_config },
+	{ .compatible = "delta,tn48m-gpi", .data = &tn48m_gpi_config },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tn48m_gpio_of_match);
+
+static struct platform_driver tn48m_gpio_driver = {
+	.driver = {
+		.name = "delta-tn48m-gpio",
+		.of_match_table = tn48m_gpio_of_match,
+	},
+	.probe = tn48m_gpio_probe,
+};
+module_platform_driver(tn48m_gpio_driver);
+
+MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
+MODULE_DESCRIPTION("Delta TN48M CPLD GPIO driver");
+MODULE_LICENSE("GPL");