[U-Boot] [PATCH v1 11/18] drivers: gpio: add driver for Microchip PIC32 GPIO controller.

[Purna Chandra Mandal]

PIC32 has ten independently programmable ports and each one with 16 pins.
These pins can be configured and used as GPIO, if they are not used by
any other peripherals.

Signed-off-by: Purna Chandra Mandal <purna.mandal at microchip.com>
---

 drivers/gpio/Kconfig      |   7 ++
 drivers/gpio/Makefile     |   2 +-
 drivers/gpio/pic32_gpio.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpio/pic32_gpio.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e60e9fd..13e9a6a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -83,4 +83,11 @@ config VYBRID_GPIO
     help
       Say yes here to support Vybrid vf610 GPIOs.
 
+config PIC32_GPIO
+    bool "Microchip PIC32 GPIO driver"
+    depends on DM_GPIO
+    default y if MACH_PIC32
+    help
+      Say yes here to support Microchip PIC32 GPIOs.
+
 endmenu
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index fb4fd25..845a6d4 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -46,4 +46,4 @@ obj-$(CONFIG_STM32_GPIO)    += stm32_gpio.o
 obj-$(CONFIG_ZYNQ_GPIO)        += zynq_gpio.o
 obj-$(CONFIG_VYBRID_GPIO)    += vybrid_gpio.o
 obj-$(CONFIG_HIKEY_GPIO)    += hi6220_gpio.o
-
+obj-$(CONFIG_PIC32_GPIO)    += pic32_gpio.o
diff --git a/drivers/gpio/pic32_gpio.c b/drivers/gpio/pic32_gpio.c
new file mode 100644
index 0000000..60b423e
--- /dev/null
+++ b/drivers/gpio/pic32_gpio.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2015 Microchip Technology Inc
+ * Purna Chandra Mandal <purna.mandal at microchip.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+#include <linux/compat.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <asm/arch-pic32/pic32.h>
+
+/* Peripheral Pin Control */
+struct pic32_gpio_regs {
+    struct pic32_reg_atomic ansel;
+    struct pic32_reg_atomic tris;
+    struct pic32_reg_atomic port;
+    struct pic32_reg_atomic lat;
+    struct pic32_reg_atomic open_drain;
+    struct pic32_reg_atomic cnpu;
+    struct pic32_reg_atomic cnpd;
+    struct pic32_reg_atomic cncon;
+};
+
+enum {
+    MICROCHIP_GPIO_DIR_OUT,
+    MICROCHIP_GPIO_DIR_IN,
+    MICROCHIP_GPIOS_PER_BANK = 16,
+};
+
+struct pic32_gpio_priv {
+    struct pic32_gpio_regs *regs;
+    char name[2];
+};
+
+static int pic32_gpio_get_value(struct udevice *dev, unsigned offset)
+{
+    struct pic32_gpio_priv *priv = dev_get_priv(dev);
+
+    return !!(readl(&priv->regs->port.raw) & BIT(offset));
+}
+
+static int pic32_gpio_set_value(struct udevice *dev, unsigned offset,
+                int value)
+{
+    struct pic32_gpio_priv *priv = dev_get_priv(dev);
+    int mask = BIT(offset);
+
+    if (value)
+        writel(mask, &priv->regs->port.set);
+    else
+        writel(mask, &priv->regs->port.clr);
+
+    return 0;
+}
+
+static int pic32_gpio_direction(struct udevice *dev, unsigned offset)
+{
+    struct pic32_gpio_priv *priv = dev_get_priv(dev);
+
+    if (readl(&priv->regs->ansel.raw) & BIT(offset))
+        return -1;
+
+    if (readl(&priv->regs->tris.raw) & BIT(offset))
+        return MICROCHIP_GPIO_DIR_IN;
+    else
+        return MICROCHIP_GPIO_DIR_OUT;
+}
+
+static int pic32_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+    struct pic32_gpio_priv *priv = dev_get_priv(dev);
+    int mask = BIT(offset);
+
+    writel(mask, &priv->regs->ansel.clr);
+    writel(mask, &priv->regs->tris.set);
+
+    return 0;
+}
+
+static int pic32_gpio_direction_output(struct udevice *dev,
+                       unsigned offset, int value)
+{
+    struct pic32_gpio_priv *priv = dev_get_priv(dev);
+    int mask = BIT(offset);
+
+    writel(mask, &priv->regs->ansel.clr);
+    writel(mask, &priv->regs->tris.clr);
+
+    pic32_gpio_set_value(dev, offset, value);
+    return 0;
+}
+
+static int pic32_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
+                struct fdtdec_phandle_args *args)
+{
+    desc->offset = args->args[0];
+    desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
+
+    return 0;
+}
+
+static int pic32_gpio_probe(struct udevice *dev)
+{
+    struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+    struct pic32_gpio_priv *priv = dev_get_priv(dev);
+    char *end;
+    int bank;
+
+    priv->regs = (struct pic32_gpio_regs *)dev_get_addr(dev);
+    uc_priv->gpio_count = MICROCHIP_GPIOS_PER_BANK;
+    end = strrchr(dev->name, '@');
+    bank = trailing_strtoln(dev->name, end);
+    priv->name[0] = 'A' + bank;
+    uc_priv->bank_name = priv->name;
+
+    return 0;
+}
+
+static int pic32_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+    int ret = GPIOF_UNUSED;
+
+    switch (pic32_gpio_direction(dev, offset)) {
+    case MICROCHIP_GPIO_DIR_OUT:
+        ret = GPIOF_OUTPUT;
+        break;
+    case MICROCHIP_GPIO_DIR_IN:
+        ret = GPIOF_INPUT;
+        break;
+    default:
+        ret = GPIOF_UNUSED;
+        break;
+    }
+    return ret;
+}
+
+static const struct dm_gpio_ops gpio_pic32_ops = {
+    .direction_input    = pic32_gpio_direction_input,
+    .direction_output    = pic32_gpio_direction_output,
+    .get_value        = pic32_gpio_get_value,
+    .set_value        = pic32_gpio_set_value,
+    .get_function        = pic32_gpio_get_function,
+    .xlate            = pic32_gpio_xlate,
+};
+
+static const struct udevice_id pic32_gpio_ids[] = {
+    { .compatible = "microchip,gpio-bank" },
+    { }
+};
+
+U_BOOT_DRIVER(gpio_pic32) = {
+    .name        = "gpio_pic32",
+    .id        = UCLASS_GPIO,
+    .of_match    = pic32_gpio_ids,
+    .ops        = &gpio_pic32_ops,
+    .probe        = pic32_gpio_probe,
+    .priv_auto_alloc_size    = sizeof(struct pic32_gpio_priv),
+};
-- 
1.8.3.1