ARC: HSDK: introduce CREG GPIO driver

The HSDK can manage some pins via CREG registers block.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

MAINTAINERS

@@ -59,6 +59,12 @@ S:	Maintained
 T:	git git://git.denx.de/u-boot-arc.git
 F:	arch/arc/
 
+ARC HSDK CREG GPIO
+M:	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
+S:	Maintained
+L:	uboot-snps-arc@synopsys.com
+F:	drivers/gpio/hsdk-creg-gpio.c
+
 ARM
 M:	Albert Aribaud <albert.u.boot@aribaud.net>
 S:	Maintained

drivers/gpio/Kconfig

@@ -80,6 +80,13 @@ config IMX_RGPIO2P
 	help
 	  This driver supports i.MX7ULP Rapid GPIO2P controller.
 
+config HSDK_CREG_GPIO
+	bool "HSDK CREG GPIO griver"
+	depends on DM
+	default n
+	help
+	  This driver supports CREG GPIOs on Synopsys HSDK SOC.
+
 config LPC32XX_GPIO
 	bool "LPC32XX GPIO driver"
 	depends on DM

drivers/gpio/Makefile

@@ -54,6 +54,7 @@ obj-$(CONFIG_GPIO_UNIPHIER)	+= gpio-uniphier.o
 obj-$(CONFIG_ZYNQ_GPIO)		+= zynq_gpio.o
 obj-$(CONFIG_VYBRID_GPIO)	+= vybrid_gpio.o
 obj-$(CONFIG_HIKEY_GPIO)	+= hi6220_gpio.o
+obj-$(CONFIG_HSDK_CREG_GPIO)	+= hsdk-creg-gpio.o
 obj-$(CONFIG_IMX_RGPIO2P)	+= imx_rgpio2p.o
 obj-$(CONFIG_PIC32_GPIO)	+= pic32_gpio.o
 obj-$(CONFIG_MVEBU_GPIO)	+= mvebu_gpio.o

drivers/gpio/hsdk-creg-gpio.c

@@ -0,0 +1,110 @@
+/*
+ * Synopsys HSDK SDP Generic PLL clock driver
+ *
+ * Copyright (C) 2017 Synopsys
+ * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <asm-generic/gpio.h>
+#include <asm/io.h>
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <linux/printk.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define HSDK_CREG_MAX_GPIO	8
+
+#define GPIO_ACTIVATE		0x2
+#define GPIO_DEACTIVATE		0x3
+#define GPIO_PIN_MASK		0x3
+#define BIT_PER_GPIO		2
+
+struct hsdk_creg_gpio {
+	uint32_t *regs;
+};
+
+static int hsdk_creg_gpio_set_value(struct udevice *dev, unsigned oft, int val)
+{
+	struct hsdk_creg_gpio *hcg = dev_get_priv(dev);
+	uint32_t reg = readl(hcg->regs);
+	uint32_t cmd = val ? GPIO_DEACTIVATE : GPIO_ACTIVATE;
+
+	reg &= ~(GPIO_PIN_MASK << (oft * BIT_PER_GPIO));
+	reg |=  (cmd << (oft * BIT_PER_GPIO));
+
+	writel(reg, hcg->regs);
+
+	return 0;
+}
+
+static int hsdk_creg_gpio_direction_output(struct udevice *dev, unsigned oft,
+					   int val)
+{
+	hsdk_creg_gpio_set_value(dev, oft, val);
+
+	return 0;
+}
+
+static int hsdk_creg_gpio_direction_input(struct udevice *dev, unsigned oft)
+{
+	pr_err("hsdk-creg-gpio can't be used as input!\n");
+
+	return -ENOTSUPP;
+}
+
+static int hsdk_creg_gpio_get_value(struct udevice *dev, unsigned int oft)
+{
+	struct hsdk_creg_gpio *hcg = dev_get_priv(dev);
+	uint32_t val = readl(hcg->regs);
+
+	val = (val >> (oft * BIT_PER_GPIO)) & GPIO_PIN_MASK;
+	return (val == GPIO_DEACTIVATE) ? 1 : 0;
+}
+
+static const struct dm_gpio_ops hsdk_creg_gpio_ops = {
+	.direction_output	= hsdk_creg_gpio_direction_output,
+	.direction_input	= hsdk_creg_gpio_direction_input,
+	.set_value		= hsdk_creg_gpio_set_value,
+	.get_value		= hsdk_creg_gpio_get_value,
+};
+
+static int hsdk_creg_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct hsdk_creg_gpio *hcg = dev_get_priv(dev);
+
+	hcg->regs = (uint32_t *)devfdt_get_addr_ptr(dev);
+
+	uc_priv->gpio_count = dev_read_u32_default(dev, "gpio-count", 1);
+	if (uc_priv->gpio_count > HSDK_CREG_MAX_GPIO)
+		uc_priv->gpio_count = HSDK_CREG_MAX_GPIO;
+
+	uc_priv->bank_name = dev_read_string(dev, "gpio-bank-name");
+	if (!uc_priv->bank_name)
+		uc_priv->bank_name = dev_read_name(dev);
+
+	pr_debug("%s GPIO [0x%p] controller with %d gpios probed\n",
+		 uc_priv->bank_name, hcg->regs, uc_priv->gpio_count);
+
+	return 0;
+}
+
+static const struct udevice_id hsdk_creg_gpio_ids[] = {
+	{ .compatible = "snps,hsdk-creg-gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_hsdk_creg) = {
+	.name	= "gpio_hsdk_creg",
+	.id	= UCLASS_GPIO,
+	.ops	= &hsdk_creg_gpio_ops,
+	.probe	= hsdk_creg_gpio_probe,
+	.of_match = hsdk_creg_gpio_ids,
+	.platdata_auto_alloc_size = sizeof(struct hsdk_creg_gpio),
+};