pinctrl: at91-pio4: Add pinctrl driver

AT91 PIO4 controller is a combined gpio-controller, pin-mux and
pin-config module. The peripheral's pins are assigned through
per-pin based muxing logic.

The pin configuration is performed on specific registers which
are shared along with the gpio controller. So regard the pinctrl
device as a child of atmel_pio4 device.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andreas Bießmann <andreas@biessmann.org>

3 files changed, 190 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 2972dba1f9..44b53b9abd 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -141,6 +141,13 @@ config ROCKCHIP_RK3288_PINCTRL
 	  definitions and pin control functions for each available multiplex
 	  function.
 
+config PINCTRL_AT91PIO4
+	bool "AT91 PIO4 pinctrl driver"
+	depends on DM
+	help
+	  This option is to enable the AT91 pinctrl driver for AT91 PIO4
+	  controller which is available on SAMA5D2 SoC.
+
 config PINCTRL_SANDBOX
 	bool "Sandbox pinctrl driver"
 	depends on SANDBOX
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 7f946814d3..c92ab8c341 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -5,6 +5,7 @@
 obj-y					+= pinctrl-uclass.o
 obj-$(CONFIG_$(SPL_)PINCTRL_GENERIC)	+= pinctrl-generic.o
 
+obj-$(CONFIG_PINCTRL_AT91PIO4)		+= pinctrl-at91-pio4.o
 obj-y					+= nxp/
 obj-$(CONFIG_ARCH_ATH79) += ath79/
 obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
new file mode 100644
index 0000000000..6d4aadc32c
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -0,0 +1,182 @@
+/*
+ * Atmel PIO4 pinctrl driver
+ *
+ * Copyright (C) 2016 Atmel Corporation
+ *               Wenyou.Yang <wenyou.yang@atmel.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm/device.h>
+#include <dm/pinctrl.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <mach/atmel_pio4.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * Warning:
+ * In order to not introduce confusion between Atmel PIO groups and pinctrl
+ * framework groups, Atmel PIO groups will be called banks.
+ */
+
+struct atmel_pio4_platdata {
+	struct atmel_pio4_port *reg_base;
+};
+
+static const struct pinconf_param conf_params[] = {
+	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
+	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
+	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
+	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
+	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
+	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
+	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
+};
+
+static u32 atmel_pinctrl_get_pinconf(const void *blob, int node)
+{
+	const struct pinconf_param *params;
+	u32 param, arg, conf = 0;
+	u32 i;
+
+	for (i = 0; i < ARRAY_SIZE(conf_params); i++) {
+		params = &conf_params[i];
+		if (!fdt_get_property(blob, node, params->property, NULL))
+			continue;
+
+		param = params->param;
+		arg = params->default_value;
+
+		switch (param) {
+		case PIN_CONFIG_BIAS_DISABLE:
+			conf &= (~ATMEL_PIO_PUEN_MASK);
+			conf &= (~ATMEL_PIO_PDEN_MASK);
+			break;
+		case PIN_CONFIG_BIAS_PULL_UP:
+			conf |= ATMEL_PIO_PUEN_MASK;
+			break;
+		case PIN_CONFIG_BIAS_PULL_DOWN:
+			conf |= ATMEL_PIO_PDEN_MASK;
+			break;
+		case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+			if (arg == 0)
+				conf &= (~ATMEL_PIO_OPD_MASK);
+			else
+				conf |= ATMEL_PIO_OPD_MASK;
+			break;
+		case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+			if (arg == 0)
+				conf |= ATMEL_PIO_SCHMITT_MASK;
+			else
+				conf &= (~ATMEL_PIO_SCHMITT_MASK);
+			break;
+		case PIN_CONFIG_INPUT_DEBOUNCE:
+			if (arg == 0) {
+				conf &= (~ATMEL_PIO_IFEN_MASK);
+				conf &= (~ATMEL_PIO_IFSCEN_MASK);
+			} else {
+				conf |= ATMEL_PIO_IFEN_MASK;
+				conf |= ATMEL_PIO_IFSCEN_MASK;
+			}
+			break;
+		default:
+			printf("%s: Unsupported configuration parameter: %u\n",
+			       __func__, param);
+			break;
+		}
+	}
+
+	return conf;
+}
+
+static inline struct atmel_pio4_port *atmel_pio4_bank_base(struct udevice *dev,
+							   u32 bank)
+{
+	struct atmel_pio4_platdata *plat = dev_get_platdata(dev);
+	struct atmel_pio4_port *bank_base =
+			(struct atmel_pio4_port *)((u32)plat->reg_base +
+			ATMEL_PIO_BANK_OFFSET * bank);
+
+	return bank_base;
+}
+
+#define MAX_PINMUX_ENTRIES	40
+
+static int atmel_pinctrl_set_state(struct udevice *dev, struct udevice *config)
+{
+	struct atmel_pio4_port *bank_base;
+	const void *blob = gd->fdt_blob;
+	int node = config->of_offset;
+	u32 offset, func, bank, line;
+	u32 cells[MAX_PINMUX_ENTRIES];
+	u32 i, conf;
+	int count;
+
+	conf = atmel_pinctrl_get_pinconf(blob, node);
+
+	count = fdtdec_get_int_array_count(blob, node, "pinmux",
+					   cells, ARRAY_SIZE(cells));
+	if (count < 0) {
+		printf("%s: bad pinmux array %d\n", __func__, count);
+		return -EINVAL;
+	}
+
+	if (count > MAX_PINMUX_ENTRIES) {
+		printf("%s: unsupported pinmux array count %d\n",
+		       __func__, count);
+		return -EINVAL;
+	}
+
+	for (i = 0 ; i < count; i++) {
+		offset = ATMEL_GET_PIN_NO(cells[i]);
+		func = ATMEL_GET_PIN_FUNC(cells[i]);
+
+		bank = ATMEL_PIO_BANK(offset);
+		line = ATMEL_PIO_LINE(offset);
+
+		bank_base = atmel_pio4_bank_base(dev, bank);
+
+		writel(BIT(line), &bank_base->mskr);
+		conf &= (~ATMEL_PIO_CFGR_FUNC_MASK);
+		conf |= (func & ATMEL_PIO_CFGR_FUNC_MASK);
+		writel(conf, &bank_base->cfgr);
+	}
+
+	return 0;
+}
+
+const struct pinctrl_ops atmel_pinctrl_ops  = {
+	.set_state = atmel_pinctrl_set_state,
+};
+
+static int atmel_pinctrl_probe(struct udevice *dev)
+{
+	struct atmel_pio4_platdata *plat = dev_get_platdata(dev);
+	fdt_addr_t addr_base;
+
+	dev = dev_get_parent(dev);
+	addr_base = dev_get_addr(dev);
+	if (addr_base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	plat->reg_base = (struct atmel_pio4_port *)addr_base;
+
+	return 0;
+}
+
+static const struct udevice_id atmel_pinctrl_match[] = {
+	{ .compatible = "atmel,sama5d2-pinctrl" },
+	{}
+};
+
+U_BOOT_DRIVER(atmel_pinctrl) = {
+	.name = "pinctrl_atmel_pio4",
+	.id = UCLASS_PINCTRL,
+	.of_match = atmel_pinctrl_match,
+	.probe = atmel_pinctrl_probe,
+	.platdata_auto_alloc_size = sizeof(struct atmel_pio4_platdata),
+	.ops = &atmel_pinctrl_ops,
+};