[U-Boot,U-BOOT,v1,1/2] gpio: fu540: add support for DM based gpio driver for FU540-SoC
diff mbox series

Message ID 1568130236-13744-2-git-send-email-sagar.kadam@sifive.com
State New
Delegated to: Andes
Headers show
Series
  • add gpio support for HiFive Unleashed A00 board.
Related show

Commit Message

Sagar Shrikant Kadam Sept. 10, 2019, 3:43 p.m. UTC
This patch adds a DM based driver model for gpio controller present in
FU540-C000 SoC on HiFive Unleashed A00 board. This SoC has one GPIO
bank and 16 GPIO lines in total, out of which GPIO0 to GPIO9 and
GPIO15 are routed to the J1 header on the board.

This implementation is ported from linux based gpio driver submitted
for review by Wesley W. Terpstra <wesley@sifive.com> and/or Atish Patra
<atish.patra@wdc.com> (many thanks !!). The linux driver can be referred
here [1]

[1]: https://lkml.org/lkml/2018/10/9/1103

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
---
 arch/riscv/include/asm/arch-generic/gpio.h |  35 +++++++
 arch/riscv/include/asm/gpio.h              |   6 ++
 drivers/gpio/Kconfig                       |   8 ++
 drivers/gpio/Makefile                      |   1 +
 drivers/gpio/sifive-gpio.c                 | 143 +++++++++++++++++++++++++++++
 5 files changed, 193 insertions(+)
 create mode 100644 arch/riscv/include/asm/arch-generic/gpio.h
 create mode 100644 arch/riscv/include/asm/gpio.h
 create mode 100644 drivers/gpio/sifive-gpio.c

Patch
diff mbox series

diff --git a/arch/riscv/include/asm/arch-generic/gpio.h b/arch/riscv/include/asm/arch-generic/gpio.h
new file mode 100644
index 0000000..7287298
--- /dev/null
+++ b/arch/riscv/include/asm/arch-generic/gpio.h
@@ -0,0 +1,35 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019 SiFive, Inc.
+ */
+
+#ifndef _GPIO_FU540_H
+#define _GPIO_FU540_H
+
+#define GPIO_INPUT_VAL	0x00
+#define GPIO_INPUT_EN	0x04
+#define GPIO_OUTPUT_EN	0x08
+#define GPIO_OUTPUT_VAL	0x0C
+#define GPIO_RISE_IE	0x18
+#define GPIO_RISE_IP	0x1C
+#define GPIO_FALL_IE	0x20
+#define GPIO_FALL_IP	0x24
+#define GPIO_HIGH_IE	0x28
+#define GPIO_HIGH_IP	0x2C
+#define GPIO_LOW_IE	0x30
+#define GPIO_LOW_IP	0x34
+#define GPIO_OUTPUT_XOR	0x40
+
+#define NR_GPIOS	16
+
+enum gpio_state {
+	LOW,
+	HIGH
+};
+
+/* Details about a GPIO bank */
+struct fu540_gpio_platdata {
+	void *base;     /* address of registers in physical memory */
+};
+
+#endif /* _GPIO_FU540_H */
diff --git a/arch/riscv/include/asm/gpio.h b/arch/riscv/include/asm/gpio.h
new file mode 100644
index 0000000..008d756
--- /dev/null
+++ b/arch/riscv/include/asm/gpio.h
@@ -0,0 +1,6 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2018 SiFive, Inc.
+ */
+
+#include <asm-generic/gpio.h>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index f2dabb5..ec48f26 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -285,6 +285,14 @@  config STM32_GPIO
 	  usable on many stm32 families like stm32f4/f7/h7 and stm32mp1.
 	  Tested on STM32F7.
 
+config SIFIVE_GPIO
+	bool "SiFive FU540 GPIO driver"
+	depends on DM_GPIO
+	help
+	  Device model driver for GPIO controller present in FU540 SoC. This
+	  driver enables GPIO interface on HiFive Unleashed A00 board a board
+	  from SiFive Inc. having FU540-C000 SoC.
+
 config MVEBU_GPIO
 	bool "Marvell MVEBU GPIO driver"
 	depends on DM_GPIO && ARCH_MVEBU
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 4a8aa0f..ccc49e2 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -61,3 +61,4 @@  obj-$(CONFIG_$(SPL_)PCF8575_GPIO)	+= pcf8575_gpio.o
 obj-$(CONFIG_PM8916_GPIO)	+= pm8916_gpio.o
 obj-$(CONFIG_MT7621_GPIO)	+= mt7621_gpio.o
 obj-$(CONFIG_MSCC_SGPIO)	+= mscc_sgpio.o
+obj-$(CONFIG_SIFIVE_GPIO)	+= sifive-gpio.o
diff --git a/drivers/gpio/sifive-gpio.c b/drivers/gpio/sifive-gpio.c
new file mode 100644
index 0000000..4bf8acf
--- /dev/null
+++ b/drivers/gpio/sifive-gpio.c
@@ -0,0 +1,143 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SiFive GPIO driver
+ *
+ * Copyright (C) 2019 SiFive, Inc.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/arch/gpio.h>
+#include <asm/io.h>
+#include <errno.h>
+#include <asm/gpio.h>
+
+static int fu540_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	uc_priv->bank_name = dev->name;
+
+	/*
+	 * Use the gpio count mentioned in device tree,
+	 * if not specified in dt, set NR_GPIOS as default
+	 */
+	uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", NR_GPIOS);
+
+	return 0;
+}
+
+static void fu540_update_gpio_reg(void *bptr, u32 offset, bool value)
+{
+	void __iomem *ptr = (void __iomem *)bptr;
+
+	u32 bit = BIT(offset);
+	u32 old = readl(ptr);
+
+	if (value)
+		writel(old | bit, ptr);
+	else
+		writel(old & ~bit, ptr);
+}
+
+static int fu540_gpio_direction_input(struct udevice *dev, u32 offset)
+{
+	struct fu540_gpio_platdata *plat = dev_get_platdata(dev);
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	if (offset > uc_priv->gpio_count)
+		return -EINVAL;
+
+	/* Configure GPIO direction as input */
+	fu540_update_gpio_reg(plat->base + GPIO_INPUT_EN,  offset, true);
+	fu540_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, false);
+
+	return 0;
+}
+
+static int fu540_gpio_direction_output(struct udevice *dev, u32 offset,
+				       int value)
+{
+	struct fu540_gpio_platdata *plat = dev_get_platdata(dev);
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	if (offset > uc_priv->gpio_count)
+		return -EINVAL;
+
+	/* Configure GPIO direction as output */
+	fu540_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, true);
+	fu540_update_gpio_reg(plat->base + GPIO_INPUT_EN,  offset, false);
+
+	/* Set the Output state of the PIN */
+	fu540_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
+
+	return 0;
+}
+
+static int fu540_gpio_get_value(struct udevice *dev, u32 offset)
+{
+	struct fu540_gpio_platdata *plat = dev_get_platdata(dev);
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	int val;
+	int dir;
+
+	if (offset > uc_priv->gpio_count)
+		return -EINVAL;
+
+	/* Get direction of the pin OUTPUT=0 INPUT=1 */
+	dir = !(readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset));
+
+	if (dir)
+		val = readl(plat->base + GPIO_INPUT_VAL) & BIT(offset);
+	else
+		val = readl(plat->base + GPIO_OUTPUT_VAL) & BIT(offset);
+
+	return val ? HIGH : LOW;
+}
+
+static int fu540_gpio_set_value(struct udevice *dev, u32 offset, int value)
+{
+	struct fu540_gpio_platdata *plat = dev_get_platdata(dev);
+
+	if (offset > NR_GPIOS)
+		return -EINVAL;
+
+	fu540_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
+
+	return 0;
+}
+
+static const struct udevice_id fu540_gpio_match[] = {
+	{ .compatible = "sifive,gpio0" },
+	{ }
+};
+
+static const struct dm_gpio_ops gpio_sifive_ops = {
+	.direction_input        = fu540_gpio_direction_input,
+	.direction_output       = fu540_gpio_direction_output,
+	.get_value              = fu540_gpio_get_value,
+	.set_value              = fu540_gpio_set_value,
+};
+
+static int fu540_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+	struct fu540_gpio_platdata *plat = dev_get_platdata(dev);
+	fdt_addr_t addr;
+
+	addr = devfdt_get_addr(dev);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	plat->base = (void *)addr;
+	return 0;
+}
+
+U_BOOT_DRIVER(gpio_sifive) = {
+	.name	= "gpio_sifive",
+	.id	= UCLASS_GPIO,
+	.of_match = fu540_gpio_match,
+	.ofdata_to_platdata = of_match_ptr(fu540_gpio_ofdata_to_platdata),
+	.platdata_auto_alloc_size = sizeof(struct fu540_gpio_platdata),
+	.ops	= &gpio_sifive_ops,
+	.probe	= fu540_gpio_probe,
+};