On 05/07/2022 14:49, lewis.hanly@xxxxxxxxxxxxx wrote:
From: Lewis Hanly <lewis.hanly@xxxxxxxxxxxxx>
Add a driver to support the Polarfire SoC gpio controller.
Signed-off-by: Lewis Hanly <lewis.hanly@xxxxxxxxxxxxx>
---
drivers/gpio/Kconfig | 7 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-mpfs.c | 358 +++++++++++++++++++++++++++++++++++++++
3 files changed, 366 insertions(+)
create mode 100644 drivers/gpio/gpio-mpfs.c
snip
diff --git a/drivers/gpio/gpio-mpfs.c b/drivers/gpio/gpio-mpfs.c
new file mode 100644
index 000000000000..df48f2836e97
--- /dev/null
+++ b/drivers/gpio/gpio-mpfs.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: (GPL-2.0)
+/*
+ * Microchip PolarFire SoC (MPFS) GPIO controller driver
+ *
+ * Copyright (c) 2018-2022 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Lewis Hanly <lewis.hanly@xxxxxxxxxxxxx>
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define NUM_GPIO 32
+#define BYTE_BOUNDARY 0x04
+#define MPFS_GPIO_EN_INT 3
+#define MPFS_GPIO_EN_OUT_BUF BIT(2)
+#define MPFS_GPIO_EN_IN BIT(1)
+#define MPFS_GPIO_EN_OUT BIT(0)
+
+#define MPFS_GPIO_TYPE_INT_EDGE_BOTH 0x80
+#define MPFS_GPIO_TYPE_INT_EDGE_NEG 0x60
+#define MPFS_GPIO_TYPE_INT_EDGE_POS 0x40
+#define MPFS_GPIO_TYPE_INT_LEVEL_LOW 0x20
+#define MPFS_GPIO_TYPE_INT_LEVEL_HIGH 0x00
+#define MPFS_GPIO_TYPE_INT_MASK GENMASK(7, 5)
+#define MPFS_IRQ_REG 0x80
+#define MPFS_INP_REG 0x84
+#define MPFS_OUTP_REG 0x88
+
+struct mpfs_gpio_chip {
+ void __iomem *base;
+ struct clk *clk;
+ spinlock_t lock; /* lock */
+ struct gpio_chip gc;
+};
+
+static void mpfs_gpio_assign_bit(void __iomem *addr, unsigned int bit_offset, int value)
+{
+ u32 output = readl(addr);
+
+ if (value)
+ output |= BIT(bit_offset);
+ else
+ output &= ~BIT(bit_offset);
+
+ writel(output, addr);
+}
+
+static int mpfs_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio_index)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ u32 gpio_cfg;
+ unsigned long flags;
+
+ if (gpio_index >= NUM_GPIO)
+ return -EINVAL;
+ spin_lock_irqsave(&mpfs_gpio->lock, flags);
+
+ gpio_cfg = readl(mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+ gpio_cfg |= MPFS_GPIO_EN_IN;
+ gpio_cfg &= ~(MPFS_GPIO_EN_OUT | MPFS_GPIO_EN_OUT_BUF);
+ writel(gpio_cfg, mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+
+ spin_unlock_irqrestore(&mpfs_gpio->lock, flags);
+
+ return 0;
+}
+
+static int mpfs_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio_index, int value)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ u32 gpio_cfg;
+ unsigned long flags;
+
+ if (gpio_index >= NUM_GPIO)
+ return -EINVAL;
Is this necessary, shouldn't gpio layer have checked this already?
+ spin_lock_irqsave(&mpfs_gpio->lock, flags);
+
+ gpio_cfg = readl(mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+ gpio_cfg |= MPFS_GPIO_EN_OUT | MPFS_GPIO_EN_OUT_BUF;
+ gpio_cfg &= ~MPFS_GPIO_EN_IN;
+ writel(gpio_cfg, mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+
+ mpfs_gpio_assign_bit(mpfs_gpio->base + MPFS_OUTP_REG, gpio_index, value);
+
+ spin_unlock_irqrestore(&mpfs_gpio->lock, flags);
+
+ return 0;
+}
+
+static int mpfs_gpio_get_direction(struct gpio_chip *gc,
+ unsigned int gpio_index)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ u32 gpio_cfg;
+
+ if (gpio_index >= NUM_GPIO)
+ return -EINVAL;
Is this necessary, shouldn't gpio layer have checked this already?
+ gpio_cfg = readl(mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+
+ if (gpio_cfg & MPFS_GPIO_EN_IN)
+ return 1;
+
+ return 0;
+}
+
+static int mpfs_gpio_get(struct gpio_chip *gc,
+ unsigned int gpio_index)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+
+ if (gpio_index >= NUM_GPIO)
+ return -EINVAL;
Is this necessary, shouldn't gpio layer have checked this already?
+ return !!(readl(mpfs_gpio->base + MPFS_INP_REG) & BIT(gpio_index));
+}
+
+static void mpfs_gpio_set(struct gpio_chip *gc, unsigned int gpio_index, int value)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ if (gpio_index >= NUM_GPIO)
+ return;
Is this necessary, shouldn't gpio layer have checked this already?
+ spin_lock_irqsave(&mpfs_gpio->lock, flags);
+
+ mpfs_gpio_assign_bit(mpfs_gpio->base + MPFS_OUTP_REG,
+ gpio_index, value);
+
+ spin_unlock_irqrestore(&mpfs_gpio->lock, flags);
+}
+
+static int mpfs_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ int gpio_index = irqd_to_hwirq(data);
+ u32 interrupt_type;
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ u32 gpio_cfg;
+ unsigned long flags;
+
+ if (gpio_index >= NUM_GPIO)
+ return -EINVAL;
Is this necessary, shouldn't gpio layer have checked this already?
+ switch (type) {
+ case IRQ_TYPE_EDGE_BOTH:
+ interrupt_type = MPFS_GPIO_TYPE_INT_EDGE_BOTH;
+ break;
+
+ case IRQ_TYPE_EDGE_FALLING:
+ interrupt_type = MPFS_GPIO_TYPE_INT_EDGE_NEG;
+ break;
+
+ case IRQ_TYPE_EDGE_RISING:
+ interrupt_type = MPFS_GPIO_TYPE_INT_EDGE_POS;
+ break;
+
+ case IRQ_TYPE_LEVEL_HIGH:
+ interrupt_type = MPFS_GPIO_TYPE_INT_LEVEL_HIGH;
+ break;
+
+ case IRQ_TYPE_LEVEL_LOW:
+ default:
+ interrupt_type = MPFS_GPIO_TYPE_INT_LEVEL_LOW;
+ break;
+ }
+
+ spin_lock_irqsave(&mpfs_gpio->lock, flags);
+
+ gpio_cfg = readl(mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+ gpio_cfg &= ~MPFS_GPIO_TYPE_INT_MASK;
+ gpio_cfg |= interrupt_type;
+ writel(gpio_cfg, mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY));
+
+ spin_unlock_irqrestore(&mpfs_gpio->lock, flags);
+
+ return 0;
+}
+
+static void mpfs_gpio_irq_enable(struct irq_data *data)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ int gpio_index = irqd_to_hwirq(data) % NUM_GPIO;
+
+ mpfs_gpio_direction_input(gc, gpio_index);
+ mpfs_gpio_assign_bit(mpfs_gpio->base + MPFS_IRQ_REG, gpio_index, 1);
+ mpfs_gpio_assign_bit(mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY),
+ MPFS_GPIO_EN_INT, 1);
+}
+
+static void mpfs_gpio_irq_disable(struct irq_data *data)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
+ int gpio_index = irqd_to_hwirq(data) % NUM_GPIO;
+
+ mpfs_gpio_assign_bit(mpfs_gpio->base + MPFS_IRQ_REG, gpio_index, 1);
+ mpfs_gpio_assign_bit(mpfs_gpio->base + (gpio_index * BYTE_BOUNDARY),
+ MPFS_GPIO_EN_INT, 0);
+}
+
+static struct irq_chip mpfs_gpio_irqchip = {
+ .name = "mpfs_gpio_irqchip",
+ .irq_set_type = mpfs_gpio_irq_set_type,
+ .irq_enable = mpfs_gpio_irq_enable,
+ .irq_disable = mpfs_gpio_irq_disable,
+ .flags = IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static irqreturn_t mpfs_gpio_irq_handler(int irq, void *mpfs_gpio_data)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = mpfs_gpio_data;
+ unsigned long status;
+ int offset;
+
+ status = readl(mpfs_gpio->base + MPFS_IRQ_REG);
+
+ for_each_set_bit(offset, &status, mpfs_gpio->gc.ngpio) {
+ mpfs_gpio_assign_bit(mpfs_gpio->base + MPFS_IRQ_REG, offset, 1);
+ generic_handle_irq(irq_find_mapping(mpfs_gpio->gc.irq.domain, offset));
+ }
+ return IRQ_HANDLED;
+}
+
+static int mpfs_gpio_probe(struct platform_device *pdev)
+{
+ struct clk *clk;
+ struct device *dev = &pdev->dev;
+ struct device_node *node = pdev->dev.of_node;
+ struct mpfs_gpio_chip *mpfs_gpio;
+ int i, ret, ngpio;
+ struct gpio_irq_chip *irq_c;
+
+ mpfs_gpio = devm_kzalloc(dev, sizeof(*mpfs_gpio), GFP_KERNEL);
+ if (!mpfs_gpio)
+ return -ENOMEM;
+
+ mpfs_gpio->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(mpfs_gpio->base)) {
+ dev_err(dev, "failed to allocate device memory\n");
+ return PTR_ERR(mpfs_gpio->base);
+ }
seems to be a mix of dev_err and dev_err_probe() in here?
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(clk), "failed to get clock\n");
+
+ ret = clk_prepare_enable(clk);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "failed to enable clock\n");
+
+ mpfs_gpio->clk = clk;
+
+ spin_lock_init(&mpfs_gpio->lock);
+
+ ngpio = of_irq_count(node);
+ if (ngpio > NUM_GPIO) {
+ dev_err(dev, "too many interrupts\n");
+ goto cleanup_clock;
+ }
+
+ mpfs_gpio->gc.direction_input = mpfs_gpio_direction_input;
+ mpfs_gpio->gc.direction_output = mpfs_gpio_direction_output;
+ mpfs_gpio->gc.get_direction = mpfs_gpio_get_direction;
+ mpfs_gpio->gc.get = mpfs_gpio_get;
+ mpfs_gpio->gc.set = mpfs_gpio_set;
+ mpfs_gpio->gc.base = -1;
+ mpfs_gpio->gc.ngpio = ngpio;
+ mpfs_gpio->gc.label = dev_name(dev);
+ mpfs_gpio->gc.parent = dev;
+ mpfs_gpio->gc.owner = THIS_MODULE;
+
+ irq_c = &mpfs_gpio->gc.irq;
+ irq_c->chip = &mpfs_gpio_irqchip;
+ irq_c->chip->parent_device = dev;
+ irq_c->handler = handle_simple_irq;
+
+ ret = devm_irq_alloc_descs(&pdev->dev, -1, 0, ngpio, 0);
+ if (ret < 0) {
+ dev_err(dev, "failed to allocate descs\n");
+ goto cleanup_clock;
+ }
+
+ /*
+ * Setup the interrupt handlers. Interrupts can be
+ * direct and/or non-direct mode, based on register value:
+ * GPIO_INTERRUPT_FAB_CR.
+ */
+ for (i = 0; i < ngpio; i++) {
+ int irq = platform_get_irq_optional(pdev, i);
+
+ if (irq < 0)
+ continue;
+
+ ret = devm_request_irq(&pdev->dev, irq,
+ mpfs_gpio_irq_handler,
+ IRQF_SHARED, mpfs_gpio->gc.label, mpfs_gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq %d: %d\n",
+ irq, ret);
+ goto cleanup_clock;
+ }
+ }
+
+ ret = gpiochip_add_data(&mpfs_gpio->gc, mpfs_gpio);
+ if (ret)
+ goto cleanup_clock;
+
+ platform_set_drvdata(pdev, mpfs_gpio);
+ dev_info(dev, "Microchip MPFS GPIO registered %d GPIOs\n", ngpio);
+
+ return 0;
+
+cleanup_clock:
+ clk_disable_unprepare(mpfs_gpio->clk);
+ return ret;
+}
do you need to deal with EPROBEDEFER in the above probe?
+
+static int mpfs_gpio_remove(struct platform_device *pdev)
+{
+ struct mpfs_gpio_chip *mpfs_gpio = platform_get_drvdata(pdev);
+
+ gpiochip_remove(&mpfs_gpio->gc);
+ clk_disable_unprepare(mpfs_gpio->clk);
+
+ return 0;
+}
+
+static const struct of_device_id mpfs_gpio_match[] = {
+ { .compatible = "microchip,mpfs-gpio", },
+ { /* end of list */ },
+};
+
+static struct platform_driver mpfs_gpio_driver = {
+ .probe = mpfs_gpio_probe,
+ .driver = {
+ .name = "microchip,mpfs-gpio",
+ .of_match_table = of_match_ptr(mpfs_gpio_match),
+ },
+ .remove = mpfs_gpio_remove,
+};
+
+builtin_platform_driver(mpfs_gpio_driver);
MODULE_AUTHOR and associated info could do with being at the bottom.
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
https://www.codethink.co.uk/privacy.html
