pinctrl: Add pinctrl driver support for Exynos7420 SoC

Add pinctrl driver support for Samsung's Exynos7420 SoC. The changes
have been split into Exynos7420 specific and common Exynos specific
portions so that this implementation is reusable on other Exynos
SoCs as well.

The Exynos pinctrl driver supports only device tree based pin
configuration. The bindings used are similar to the ones used in the
linux kernel.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

1 files changed, 141 insertions, 0 deletions

diff --git a/drivers/pinctrl/exynos/pinctrl-exynos.c b/drivers/pinctrl/exynos/pinctrl-exynos.c
new file mode 100644
index 0000000000..a28405fc15
--- /dev/null
+++ b/drivers/pinctrl/exynos/pinctrl-exynos.c
@@ -0,0 +1,141 @@
+/*
+ * Exynos pinctrl driver common code.
+ * Copyright (C) 2016 Samsung Electronics
+ * Thomas Abraham <thomas.ab@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/io.h>
+#include "pinctrl-exynos.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * exynos_pinctrl_setup_peri: setup pinctrl for a peripheral.
+ * conf: soc specific pin configuration data array
+ * num_conf: number of configurations in the conf array.
+ * base: base address of the pin controller.
+ */
+void exynos_pinctrl_setup_peri(struct exynos_pinctrl_config_data *conf,
+		unsigned int num_conf, unsigned long base)
+{
+	unsigned int idx, val;
+
+	for (idx = 0; idx < num_conf; idx++) {
+		val = readl(base + conf[idx].offset);
+		val &= ~(conf[idx].mask);
+		val |= conf[idx].value;
+		writel(val, base + conf[idx].offset);
+	}
+}
+
+/* given a pin-name, return the address of pin config registers */
+static unsigned long pin_to_bank_base(struct udevice *dev, const char *pin_name,
+						u32 *pin)
+{
+	struct exynos_pinctrl_priv *priv = dev_get_priv(dev);
+	const struct samsung_pin_ctrl *pin_ctrl = priv->pin_ctrl;
+	const struct samsung_pin_bank_data *bank_data = pin_ctrl->pin_banks;
+	u32 nr_banks = pin_ctrl->nr_banks, idx = 0;
+	char bank[10];
+
+	/*
+	 * The format of the pin name is <bank name>-<pin_number>.
+	 * Example: gpa0-4 (gpa0 is the bank name and 4 is the pin number.
+	 */
+	while (pin_name[idx] != '-') {
+		bank[idx] = pin_name[idx];
+		idx++;
+	}
+	bank[idx] = '\0';
+	*pin = pin_name[++idx] - '0';
+
+	/* lookup the pin bank data using the pin bank name */
+	for (idx = 0; idx < nr_banks; idx++)
+		if (!strcmp(bank, bank_data[idx].name))
+			break;
+
+	return priv->base + bank_data[idx].offset;
+}
+
+/**
+ * exynos_pinctrl_set_state: configure a pin state.
+ * dev: the pinctrl device to be configured.
+ * config: the state to be configured.
+ */
+int exynos_pinctrl_set_state(struct udevice *dev, struct udevice *config)
+{
+	const void *fdt = gd->fdt_blob;
+	int node = config->of_offset;
+	unsigned int count, idx, pin_num, ret;
+	unsigned int pinfunc, pinpud, pindrv;
+	unsigned long reg, value;
+	const char *name;
+
+	/*
+	 * refer to the following document for the pinctrl bindings
+	 * linux/Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt
+	 */
+	count = fdt_count_strings(fdt, node, "samsung,pins");
+	if (count <= 0)
+		return -EINVAL;
+
+	pinfunc = fdtdec_get_int(fdt, node, "samsung,pin-function", -1);
+	pinpud = fdtdec_get_int(fdt, node, "samsung,pin-pud", -1);
+	pindrv = fdtdec_get_int(fdt, node, "samsung,pin-drv", -1);
+
+	for (idx = 0; idx < count; idx++) {
+		ret = fdt_get_string_index(fdt, node, "samsung,pins",
+						idx, &name);
+		if (ret < 0)
+			continue;
+		reg = pin_to_bank_base(dev, name, &pin_num);
+
+		if (pinfunc != -1) {
+			value = readl(reg + PIN_CON);
+			value &= ~(0xf << (pin_num << 2));
+			value |= (pinfunc << (pin_num << 2));
+			writel(value, reg + PIN_CON);
+		}
+
+		if (pinpud != -1) {
+			value = readl(reg + PIN_PUD);
+			value &= ~(0x3 << (pin_num << 1));
+			value |= (pinpud << (pin_num << 1));
+			writel(value, reg + PIN_PUD);
+		}
+
+		if (pindrv != -1) {
+			value = readl(reg + PIN_DRV);
+			value &= ~(0x3 << (pin_num << 1));
+			value |= (pindrv << (pin_num << 1));
+			writel(value, reg + PIN_DRV);
+		}
+	}
+
+	return 0;
+}
+
+int exynos_pinctrl_probe(struct udevice *dev)
+{
+	struct exynos_pinctrl_priv *priv;
+	fdt_addr_t base;
+
+	priv = dev_get_priv(dev);
+	if (!priv)
+		return -EINVAL;
+
+	base = dev_get_addr(dev);
+	if (base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	priv->base = base;
+	priv->pin_ctrl = (struct samsung_pin_ctrl *)dev_get_driver_data(dev) +
+				dev->req_seq;
+
+	return 0;
+}