gpio: sifive: add support for DM based gpio driver for FU540-SoC

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>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/riscv/include/asm/arch-generic/gpio.h b/arch/riscv/include/asm/arch-generic/gpio.h
new file mode 100644 (file)
index 0000000..dfcb753
--- /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_SIFIVE_H
+#define _GPIO_SIFIVE_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 sifive_gpio_platdata {
+       void *base;     /* address of registers in physical memory */
+};
+
+#endif /* _GPIO_SIFIVE_H */

diff --git a/arch/riscv/include/asm/gpio.h b/arch/riscv/include/asm/gpio.h
new file mode 100644 (file)
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 f2dabb554fa9b2d67ebf2f57e0f084a947f6884e..39f2c7e3283313ca428fea559af64348e859552b 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -285,6 +285,13 @@ config STM32_GPIO
          usable on many stm32 families like stm32f4/f7/h7 and stm32mp1.
          Tested on STM32F7.
 
+config SIFIVE_GPIO
+       bool "SiFive GPIO driver"
+       depends on DM_GPIO
+       help
+         Device model driver for GPIO controller present in SiFive FU540 SoC. This
+         driver enables GPIO interface on HiFive Unleashed A00 board.
+
 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 4a8aa0ff6fe684d3014bfc13795bd3652a4f865f..ccc49e2eb02d1bfb123ee44b536e04ae386abeee 100644 (file)
--- 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 (file)
index 0000000..76d5a1d
--- /dev/null
+++ b/drivers/gpio/sifive-gpio.c
@@ -0,0 +1,177 @@
+// 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 sifive_gpio_probe(struct udevice *dev)
+{
+       struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
+       struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+       char name[18], *str;
+
+       sprintf(name, "gpio@%4lx_", (uintptr_t)plat->base);
+       str = strdup(name);
+       if (!str)
+               return -ENOMEM;
+       uc_priv->bank_name = str;
+
+       /*
+        * 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 sifive_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 sifive_gpio_direction_input(struct udevice *dev, u32 offset)
+{
+       struct sifive_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 */
+       sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN,  offset, true);
+       sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, false);
+
+       return 0;
+}
+
+static int sifive_gpio_direction_output(struct udevice *dev, u32 offset,
+                                       int value)
+{
+       struct sifive_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 */
+       sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, true);
+       sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN,  offset, false);
+
+       /* Set the output state of the pin */
+       sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
+
+       return 0;
+}
+
+static int sifive_gpio_get_value(struct udevice *dev, u32 offset)
+{
+       struct sifive_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 */
+       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 sifive_gpio_set_value(struct udevice *dev, u32 offset, int value)
+{
+       struct sifive_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;
+
+       sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
+
+       return 0;
+}
+
+static int sifive_gpio_get_function(struct udevice *dev, unsigned int offset)
+{
+       struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
+       u32     outdir, indir, val;
+       struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+       if (offset > uc_priv->gpio_count)
+               return -1;
+
+       /* Get direction of the pin */
+       outdir = readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset);
+       indir  = readl(plat->base + GPIO_INPUT_EN) & BIT(offset);
+
+       if (outdir)
+               /* Pin at specified offset is configured as output */
+               val = GPIOF_OUTPUT;
+       else if (indir)
+               /* Pin at specified offset is configured as input */
+               val = GPIOF_INPUT;
+       else
+               /*The requested GPIO is not set as input or output */
+               val = GPIOF_UNUSED;
+
+       return val;
+}
+
+static const struct udevice_id sifive_gpio_match[] = {
+       { .compatible = "sifive,gpio0" },
+       { }
+};
+
+static const struct dm_gpio_ops sifive_gpio_ops = {
+       .direction_input        = sifive_gpio_direction_input,
+       .direction_output       = sifive_gpio_direction_output,
+       .get_value              = sifive_gpio_get_value,
+       .set_value              = sifive_gpio_set_value,
+       .get_function           = sifive_gpio_get_function,
+};
+
+static int sifive_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+       struct sifive_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 = sifive_gpio_match,
+       .ofdata_to_platdata = of_match_ptr(sifive_gpio_ofdata_to_platdata),
+       .platdata_auto_alloc_size = sizeof(struct sifive_gpio_platdata),
+       .ops    = &sifive_gpio_ops,
+       .probe  = sifive_gpio_probe,
+};