[PATCH v2 2/4] gpio: Add Delta TN48M CPLD GPIO driver

From: Robert Marko
Date: Mon May 24 2021 - 08:05:57 EST


Delta TN48M CPLD is used as a GPIO expander for the SFP GPIOs.

It is a mix of input only and output only pins.

Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
---
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 | 89 +++++++++++++++++++++++++++++++++++++++
3 files changed, 102 insertions(+)
create mode 100644 drivers/gpio/gpio-tn48m.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 1dd0ec6727fd..46caf72960e6 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1332,6 +1332,18 @@ 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 CPLD.
+ They are used for inputs and outputs on the SFP slots.
+
+ 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 d7c81e1611a4..07fa6419305f 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -147,6 +147,7 @@ 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..41484c002826
--- /dev/null
+++ b/drivers/gpio/gpio-tn48m.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Delta TN48M CPLD GPIO driver
+ *
+ * Copyright 2021 Sartura Ltd
+ *
+ * Author: Robert Marko <robert.marko@xxxxxxxxxx>
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+enum tn48m_gpio_type {
+ TN48M_SFP_TX_DISABLE = 1,
+ TN48M_SFP_PRESENT,
+ TN48M_SFP_LOS,
+};
+
+static int tn48m_gpio_probe(struct platform_device *pdev)
+{
+ struct gpio_regmap_config config = {0};
+ enum tn48m_gpio_type type;
+ struct regmap *regmap;
+ u32 base;
+ int ret;
+
+ if (!pdev->dev.parent)
+ return -ENODEV;
+
+ type = (uintptr_t)device_get_match_data(&pdev->dev);
+ if (!type)
+ return -ENODEV;
+
+ ret = device_property_read_u32(&pdev->dev, "reg", &base);
+ if (ret)
+ return -EINVAL;
+
+ regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!regmap)
+ return -ENODEV;
+
+ config.regmap = regmap;
+ config.parent = &pdev->dev;
+ config.ngpio = 4;
+
+ switch (type) {
+ case TN48M_SFP_TX_DISABLE:
+ config.reg_set_base = base;
+ break;
+ case TN48M_SFP_PRESENT:
+ config.reg_dat_base = base;
+ break;
+ case TN48M_SFP_LOS:
+ config.reg_dat_base = base;
+ break;
+ default:
+ dev_err(&pdev->dev, "unknown type %d\n", type);
+ return -ENODEV;
+ }
+
+ 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-gpio-sfp-tx-disable", .data = (void *)TN48M_SFP_TX_DISABLE },
+ { .compatible = "delta,tn48m-gpio-sfp-present", .data = (void *)TN48M_SFP_PRESENT },
+ { .compatible = "delta,tn48m-gpio-sfp-los", .data = (void *)TN48M_SFP_LOS },
+ { }
+};
+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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Delta TN48M CPLD GPIO driver");
+MODULE_LICENSE("GPL");
--
2.31.1