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Message-ID: <20210922135319.3128153-4-piyush.mehta@xilinx.com>
Date: Wed, 22 Sep 2021 19:23:19 +0530
From: Piyush Mehta <piyush.mehta@...inx.com>
To: <arnd@...db.de>, <zou_wei@...wei.com>,
<gregkh@...uxfoundation.org>, <linus.walleij@...aro.org>,
<michal.simek@...inx.com>, <wendy.liang@...inx.com>,
<iwamatsu@...auri.org>, <bgolaszewski@...libre.com>,
<robh+dt@...nel.org>, <rajan.vaja@...inx.com>
CC: <linux-gpio@...r.kernel.org>, <devicetree@...r.kernel.org>,
<git@...inx.com>, <sgoud@...inx.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>,
Piyush Mehta <piyush.mehta@...inx.com>
Subject: [PATCH V4 3/3] gpio: modepin: Add driver support for modepin GPIO controller
This patch adds driver support for the zynqmp modepin GPIO controller.
GPIO modepin driver set and get the value and status of the PS_MODE pin,
based on device-tree pin configuration. These four mode pins are
configurable as input/output. The mode pin has a control register, which
have lower four-bits [0:3] are configurable as input/output, next four-bits
can be used for reading the data as input[4:7], and next setting the
output pin state output[8:11]. By default value of mode pin register is 0.
Signed-off-by: Piyush Mehta <piyush.mehta@...inx.com>
Acked-by: Michal Simek <michal.simek@...inx.com>
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
---
Changes in v2:
- Modepin driver- Addressed review comments:
- Update APIs
- Removed unwanted variables
- Handle return path for probe function
Review Comments:
https://lore.kernel.org/linux-arm-kernel/20210615080553.2021061-2-piyush.mehta@xilinx.com/T/#m276c8a5c52f8dc1ed1cd91a2d660f78d498e4ae5
Changes in v3:
- Addressed Linus and Arnd review comments:
- Update probe function return value
- Remove unnecessary print and header file
- Update error message for set value method
Review Comments:
https://lore.kernel.org/linux-arm-kernel/20210805174219.3000667-4-piyush.mehta@xilinx.com/T/#m70acd39653033e32458633e21a2e6d21afdd16e6
Changes in v4:
- Added input pin read status in modepin_gpio_get_value.
- Updated modepin control bit for out configuration on set_value.
Review Comments:
https://lore.kernel.org/linux-arm-kernel/554508f5-8cb5-3840-9f61-f6cd6e5745d2@xilinx.com/T/#u
https://lore.kernel.org/linux-arm-kernel/554508f5-8cb5-3840-9f61-f6cd6e5745d2@xilinx.com/T/#m60039005ebee312260d344c7d4383acb43c50f0f
---
drivers/gpio/Kconfig | 12 +++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-zynqmp-modepin.c | 162 +++++++++++++++++++++++++++++++++++++
3 files changed, 175 insertions(+)
create mode 100644 drivers/gpio/gpio-zynqmp-modepin.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index fae5141..37a6f77 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -763,6 +763,18 @@ config GPIO_ZYNQ
help
Say yes here to support Xilinx Zynq GPIO controller.
+config GPIO_ZYNQMP_MODEPIN
+ tristate "ZynqMP ps-mode pin gpio configuration driver"
+ depends on ZYNQMP_FIRMWARE
+ default ZYNQMP_FIRMWARE
+ help
+ Say yes here to support the ZynqMP ps-mode pin gpio configuration
+ driver.
+
+ This ps-mode pin gpio driver is based on GPIO framework, PS_MODE
+ is 4-bits boot mode pins. It sets and gets the status of
+ the ps-mode pin. Every pin can be configured as input/output.
+
config GPIO_LOONGSON1
tristate "Loongson1 GPIO support"
depends on MACH_LOONGSON32
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index fbcda63..71ee9fc2 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -184,3 +184,4 @@ obj-$(CONFIG_GPIO_XRA1403) += gpio-xra1403.o
obj-$(CONFIG_GPIO_XTENSA) += gpio-xtensa.o
obj-$(CONFIG_GPIO_ZEVIO) += gpio-zevio.o
obj-$(CONFIG_GPIO_ZYNQ) += gpio-zynq.o
+obj-$(CONFIG_GPIO_ZYNQMP_MODEPIN) += gpio-zynqmp-modepin.o
diff --git a/drivers/gpio/gpio-zynqmp-modepin.c b/drivers/gpio/gpio-zynqmp-modepin.c
new file mode 100644
index 0000000..a0d6938
--- /dev/null
+++ b/drivers/gpio/gpio-zynqmp-modepin.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the ps-mode pin configuration.
+ *
+ * Copyright (c) 2021 Xilinx, Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/firmware/xlnx-zynqmp.h>
+
+/* 4-bit boot mode pins */
+#define MODE_PINS 4
+
+/**
+ * modepin_gpio_get_value - Get the state of the specified pin of GPIO device
+ * @chip: gpio_chip instance to be worked on
+ * @pin: gpio pin number within the device
+ *
+ * This function reads the state of the specified pin of the GPIO device.
+ *
+ * Return: 0 if the pin is low, 1 if pin is high, -EINVAL wrong pin configured
+ * or error value.
+ */
+static int modepin_gpio_get_value(struct gpio_chip *chip, unsigned int pin)
+{
+ u32 regval = 0;
+ int ret;
+
+ ret = zynqmp_pm_bootmode_read(®val);
+ if (ret)
+ return ret;
+
+ /* When [0:3] corresponding bit is set, then read output bit [8:11],
+ * if the bit is clear then read input bit [4:7] for status or value.
+ */
+ if (regval & BIT(pin))
+ return !!(regval & BIT(pin + 8));
+ else
+ return !!(regval & BIT(pin + 4));
+}
+
+/**
+ * modepin_gpio_set_value - Modify the state of the pin with specified value
+ * @chip: gpio_chip instance to be worked on
+ * @pin: gpio pin number within the device
+ * @state: value used to modify the state of the specified pin
+ *
+ * This function reads the state of the specified pin of the GPIO device, mask
+ * with the capture state of GPIO pin, and update pin of GPIO device.
+ *
+ * Return: None.
+ */
+static void modepin_gpio_set_value(struct gpio_chip *chip, unsigned int pin,
+ int state)
+{
+ u32 bootpin_val = 0;
+ int ret;
+
+ zynqmp_pm_bootmode_read(&bootpin_val);
+
+ /* Configure pin as an output by set bit [0:3] */
+ bootpin_val |= BIT(pin);
+
+ if (state)
+ bootpin_val |= BIT(pin + 8);
+ else
+ bootpin_val &= ~BIT(pin + 8);
+
+ /* Configure bootpin value */
+ ret = zynqmp_pm_bootmode_write(bootpin_val);
+ if (ret)
+ pr_err("modepin: set value error %d for pin %d\n", ret, pin);
+}
+
+/**
+ * modepin_gpio_dir_in - Set the direction of the specified GPIO pin as input
+ * @chip: gpio_chip instance to be worked on
+ * @pin: gpio pin number within the device
+ *
+ * Return: 0 always
+ */
+static int modepin_gpio_dir_in(struct gpio_chip *chip, unsigned int pin)
+{
+ return 0;
+}
+
+/**
+ * modepin_gpio_dir_out - Set the direction of the specified GPIO pin as output
+ * @chip: gpio_chip instance to be worked on
+ * @pin: gpio pin number within the device
+ * @state: value to be written to specified pin
+ *
+ * Return: 0 always
+ */
+static int modepin_gpio_dir_out(struct gpio_chip *chip, unsigned int pin,
+ int state)
+{
+ return 0;
+}
+
+/**
+ * modepin_gpio_probe - Initialization method for modepin_gpio
+ * @pdev: platform device instance
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+static int modepin_gpio_probe(struct platform_device *pdev)
+{
+ struct gpio_chip *chip;
+ int status;
+
+ chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, chip);
+
+ /* configure the gpio chip */
+ chip->base = -1;
+ chip->ngpio = MODE_PINS;
+ chip->owner = THIS_MODULE;
+ chip->parent = &pdev->dev;
+ chip->get = modepin_gpio_get_value;
+ chip->set = modepin_gpio_set_value;
+ chip->direction_input = modepin_gpio_dir_in;
+ chip->direction_output = modepin_gpio_dir_out;
+ chip->label = dev_name(&pdev->dev);
+
+ /* modepin gpio registration */
+ status = devm_gpiochip_add_data(&pdev->dev, chip, chip);
+ if (status)
+ return dev_err_probe(&pdev->dev, status,
+ "Failed to add GPIO chip\n");
+
+ return status;
+}
+
+static const struct of_device_id modepin_platform_id[] = {
+ { .compatible = "xlnx,zynqmp-gpio-modepin", },
+ { }
+};
+
+static struct platform_driver modepin_platform_driver = {
+ .driver = {
+ .name = "modepin-gpio",
+ .of_match_table = modepin_platform_id,
+ },
+ .probe = modepin_gpio_probe,
+};
+
+module_platform_driver(modepin_platform_driver);
+
+MODULE_AUTHOR("Piyush Mehta <piyush.mehta@...inx.com>");
+MODULE_DESCRIPTION("ZynqMP Boot PS_MODE Configuration");
+MODULE_LICENSE("GPL v2");
--
2.7.4
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