pinctrl: Add Microsemi Ocelot SoC driver

The Microsemi Ocelot SoC has a few pins that can be used as GPIOs or take
multiple other functions. Add a driver for the pinmuxing and the GPIOs.

There is currently no support for interrupts.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 511 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-ocelot.c b/drivers/pinctrl/pinctrl-ocelot.c
new file mode 100644
index 000000000000..01a50d969111
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-ocelot.c
@@ -0,0 +1,511 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Microsemi SoCs pinctrl driver
+ *
+ * Author: <alexandre.belloni@free-electrons.com>
+ * License: Dual MIT/GPL
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "core.h"
+#include "pinconf.h"
+#include "pinmux.h"
+
+#define OCELOT_GPIO_OUT_SET	0x0
+#define OCELOT_GPIO_OUT_CLR	0x4
+#define OCELOT_GPIO_OUT		0x8
+#define OCELOT_GPIO_IN		0xc
+#define OCELOT_GPIO_OE		0x10
+#define OCELOT_GPIO_INTR	0x14
+#define OCELOT_GPIO_INTR_ENA	0x18
+#define OCELOT_GPIO_INTR_IDENT	0x1c
+#define OCELOT_GPIO_ALT0	0x20
+#define OCELOT_GPIO_ALT1	0x24
+#define OCELOT_GPIO_SD_MAP	0x28
+
+#define OCELOT_PINS		22
+#define OCELOT_FUNC_PER_PIN	4
+
+enum {
+	FUNC_NONE,
+	FUNC_GPIO,
+	FUNC_IRQ0_IN,
+	FUNC_IRQ0_OUT,
+	FUNC_IRQ1_IN,
+	FUNC_IRQ1_OUT,
+	FUNC_MIIM1,
+	FUNC_PCI_WAKE,
+	FUNC_PTP0,
+	FUNC_PTP1,
+	FUNC_PTP2,
+	FUNC_PTP3,
+	FUNC_PWM,
+	FUNC_RECO_CLK0,
+	FUNC_RECO_CLK1,
+	FUNC_SFP0,
+	FUNC_SFP1,
+	FUNC_SFP2,
+	FUNC_SFP3,
+	FUNC_SFP4,
+	FUNC_SFP5,
+	FUNC_SG0,
+	FUNC_SI,
+	FUNC_TACHO,
+	FUNC_TWI,
+	FUNC_TWI_SCL_M,
+	FUNC_UART,
+	FUNC_UART2,
+	FUNC_MAX
+};
+
+static const char *const ocelot_function_names[] = {
+	[FUNC_NONE]		= "none",
+	[FUNC_GPIO]		= "gpio",
+	[FUNC_IRQ0_IN]		= "irq0_in",
+	[FUNC_IRQ0_OUT]		= "irq0_out",
+	[FUNC_IRQ1_IN]		= "irq1_in",
+	[FUNC_IRQ1_OUT]		= "irq1_out",
+	[FUNC_MIIM1]		= "miim1",
+	[FUNC_PCI_WAKE]		= "pci_wake",
+	[FUNC_PTP0]		= "ptp0",
+	[FUNC_PTP1]		= "ptp1",
+	[FUNC_PTP2]		= "ptp2",
+	[FUNC_PTP3]		= "ptp3",
+	[FUNC_PWM]		= "pwm",
+	[FUNC_RECO_CLK0]	= "reco_clk0",
+	[FUNC_RECO_CLK1]	= "reco_clk1",
+	[FUNC_SFP0]		= "sfp0",
+	[FUNC_SFP1]		= "sfp1",
+	[FUNC_SFP2]		= "sfp2",
+	[FUNC_SFP3]		= "sfp3",
+	[FUNC_SFP4]		= "sfp4",
+	[FUNC_SFP5]		= "sfp5",
+	[FUNC_SG0]		= "sg0",
+	[FUNC_SI]		= "si",
+	[FUNC_TACHO]		= "tacho",
+	[FUNC_TWI]		= "twi",
+	[FUNC_TWI_SCL_M]	= "twi_scl_m",
+	[FUNC_UART]		= "uart",
+	[FUNC_UART2]		= "uart2",
+};
+
+struct ocelot_pmx_func {
+	const char **groups;
+	unsigned int ngroups;
+};
+
+struct ocelot_pin_caps {
+	unsigned int pin;
+	unsigned char functions[OCELOT_FUNC_PER_PIN];
+};
+
+struct ocelot_pinctrl {
+	struct device *dev;
+	struct pinctrl_dev *pctl;
+	struct gpio_chip gpio_chip;
+	struct regmap *map;
+	struct ocelot_pmx_func func[FUNC_MAX];
+};
+
+#define OCELOT_P(p, f0, f1, f2)						\
+static struct ocelot_pin_caps ocelot_pin_##p = {			\
+	.pin = p,							\
+	.functions = {							\
+			FUNC_GPIO, FUNC_##f0, FUNC_##f1, FUNC_##f2,	\
+	},								\
+}
+
+OCELOT_P(0,  SG0,       NONE,      NONE);
+OCELOT_P(1,  SG0,       NONE,      NONE);
+OCELOT_P(2,  SG0,       NONE,      NONE);
+OCELOT_P(3,  SG0,       NONE,      NONE);
+OCELOT_P(4,  IRQ0_IN,   IRQ0_OUT,  TWI);
+OCELOT_P(5,  IRQ1_IN,   IRQ1_OUT,  PCI_WAKE);
+OCELOT_P(6,  UART,      TWI_SCL_M, NONE);
+OCELOT_P(7,  UART,      TWI_SCL_M, NONE);
+OCELOT_P(8,  SI,        TWI_SCL_M, IRQ0_OUT);
+OCELOT_P(9,  SI,        TWI_SCL_M, IRQ1_OUT);
+OCELOT_P(10, PTP2,      TWI_SCL_M, SFP0);
+OCELOT_P(11, PTP3,      TWI_SCL_M, SFP1);
+OCELOT_P(12, UART2,     TWI_SCL_M, SFP2);
+OCELOT_P(13, UART2,     TWI_SCL_M, SFP3);
+OCELOT_P(14, MIIM1,     TWI_SCL_M, SFP4);
+OCELOT_P(15, MIIM1,     TWI_SCL_M, SFP5);
+OCELOT_P(16, TWI,       NONE,      SI);
+OCELOT_P(17, TWI,       TWI_SCL_M, SI);
+OCELOT_P(18, PTP0,      TWI_SCL_M, NONE);
+OCELOT_P(19, PTP1,      TWI_SCL_M, NONE);
+OCELOT_P(20, RECO_CLK0, TACHO,     NONE);
+OCELOT_P(21, RECO_CLK1, PWM,       NONE);
+
+#define OCELOT_PIN(n) {						\
+	.number = n,						\
+	.name = "GPIO_"#n,					\
+	.drv_data = &ocelot_pin_##n				\
+}
+
+static const struct pinctrl_pin_desc ocelot_pins[] = {
+	OCELOT_PIN(0),
+	OCELOT_PIN(1),
+	OCELOT_PIN(2),
+	OCELOT_PIN(3),
+	OCELOT_PIN(4),
+	OCELOT_PIN(5),
+	OCELOT_PIN(6),
+	OCELOT_PIN(7),
+	OCELOT_PIN(8),
+	OCELOT_PIN(9),
+	OCELOT_PIN(10),
+	OCELOT_PIN(11),
+	OCELOT_PIN(12),
+	OCELOT_PIN(13),
+	OCELOT_PIN(14),
+	OCELOT_PIN(15),
+	OCELOT_PIN(16),
+	OCELOT_PIN(17),
+	OCELOT_PIN(18),
+	OCELOT_PIN(19),
+	OCELOT_PIN(20),
+	OCELOT_PIN(21),
+};
+
+static int ocelot_get_functions_count(struct pinctrl_dev *pctldev)
+{
+	return ARRAY_SIZE(ocelot_function_names);
+}
+
+static const char *ocelot_get_function_name(struct pinctrl_dev *pctldev,
+					    unsigned int function)
+{
+	return ocelot_function_names[function];
+}
+
+static int ocelot_get_function_groups(struct pinctrl_dev *pctldev,
+				      unsigned int function,
+				      const char *const **groups,
+				      unsigned *const num_groups)
+{
+	struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	*groups  = info->func[function].groups;
+	*num_groups = info->func[function].ngroups;
+
+	return 0;
+}
+
+static int ocelot_pin_function_idx(unsigned int pin, unsigned int function)
+{
+	struct ocelot_pin_caps *p = ocelot_pins[pin].drv_data;
+	int i;
+
+	for (i = 0; i < OCELOT_FUNC_PER_PIN; i++) {
+		if (function == p->functions[i])
+			return i;
+	}
+
+	return -1;
+}
+
+static int ocelot_pinmux_set_mux(struct pinctrl_dev *pctldev,
+				 unsigned int selector, unsigned int group)
+{
+	struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	struct ocelot_pin_caps *pin = ocelot_pins[group].drv_data;
+	int f;
+
+	f = ocelot_pin_function_idx(group, selector);
+	if (f < 0)
+		return -EINVAL;
+
+	/*
+	 * f is encoded on two bits.
+	 * bit 0 of f goes in BIT(pin) of ALT0, bit 1 of f goes in BIT(pin) of
+	 * ALT1
+	 * This is racy because both registers can't be updated at the same time
+	 * but it doesn't matter much for now.
+	 */
+	regmap_update_bits(info->map, OCELOT_GPIO_ALT0, BIT(pin->pin),
+			   f << pin->pin);
+	regmap_update_bits(info->map, OCELOT_GPIO_ALT1, BIT(pin->pin),
+			   f << (pin->pin - 1));
+
+	return 0;
+}
+
+static int ocelot_gpio_set_direction(struct pinctrl_dev *pctldev,
+				     struct pinctrl_gpio_range *range,
+				     unsigned int pin, bool input)
+{
+	struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	regmap_update_bits(info->map, OCELOT_GPIO_OE, BIT(pin),
+			   input ? BIT(pin) : 0);
+
+	return 0;
+}
+
+static int ocelot_gpio_request_enable(struct pinctrl_dev *pctldev,
+				      struct pinctrl_gpio_range *range,
+				      unsigned int offset)
+{
+	struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	regmap_update_bits(info->map, OCELOT_GPIO_ALT0, BIT(offset), 0);
+	regmap_update_bits(info->map, OCELOT_GPIO_ALT1, BIT(offset), 0);
+
+	return 0;
+}
+
+static const struct pinmux_ops ocelot_pmx_ops = {
+	.get_functions_count = ocelot_get_functions_count,
+	.get_function_name = ocelot_get_function_name,
+	.get_function_groups = ocelot_get_function_groups,
+	.set_mux = ocelot_pinmux_set_mux,
+	.gpio_set_direction = ocelot_gpio_set_direction,
+	.gpio_request_enable = ocelot_gpio_request_enable,
+};
+
+static int ocelot_pctl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	return ARRAY_SIZE(ocelot_pins);
+}
+
+static const char *ocelot_pctl_get_group_name(struct pinctrl_dev *pctldev,
+					      unsigned int group)
+{
+	return ocelot_pins[group].name;
+}
+
+static int ocelot_pctl_get_group_pins(struct pinctrl_dev *pctldev,
+				      unsigned int group,
+				      const unsigned int **pins,
+				      unsigned int *num_pins)
+{
+	*pins = &ocelot_pins[group].number;
+	*num_pins = 1;
+
+	return 0;
+}
+
+static const struct pinctrl_ops ocelot_pctl_ops = {
+	.get_groups_count = ocelot_pctl_get_groups_count,
+	.get_group_name = ocelot_pctl_get_group_name,
+	.get_group_pins = ocelot_pctl_get_group_pins,
+	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+	.dt_free_map = pinconf_generic_dt_free_map,
+};
+
+static struct pinctrl_desc ocelot_desc = {
+	.name = "ocelot-pinctrl",
+	.pins = ocelot_pins,
+	.npins = ARRAY_SIZE(ocelot_pins),
+	.pctlops = &ocelot_pctl_ops,
+	.pmxops = &ocelot_pmx_ops,
+	.owner = THIS_MODULE,
+};
+
+static int ocelot_create_group_func_map(struct device *dev,
+					struct ocelot_pinctrl *info)
+{
+	u16 pins[ARRAY_SIZE(ocelot_pins)];
+	int f, npins, i;
+
+	for (f = 0; f < FUNC_MAX; f++) {
+		for (npins = 0, i = 0; i < ARRAY_SIZE(ocelot_pins); i++) {
+			if (ocelot_pin_function_idx(i, f) >= 0)
+				pins[npins++] = i;
+		}
+
+		info->func[f].ngroups = npins;
+		info->func[f].groups = devm_kzalloc(dev, npins *
+							 sizeof(char *),
+							 GFP_KERNEL);
+		if (!info->func[f].groups)
+			return -ENOMEM;
+
+		for (i = 0; i < npins; i++)
+			info->func[f].groups[i] = ocelot_pins[pins[i]].name;
+	}
+
+	return 0;
+}
+
+static int ocelot_pinctrl_register(struct platform_device *pdev,
+				   struct ocelot_pinctrl *info)
+{
+	int ret;
+
+	ret = ocelot_create_group_func_map(&pdev->dev, info);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to create group func map.\n");
+		return ret;
+	}
+
+	info->pctl = devm_pinctrl_register(&pdev->dev, &ocelot_desc, info);
+	if (IS_ERR(info->pctl)) {
+		dev_err(&pdev->dev, "Failed to register pinctrl\n");
+		return PTR_ERR(info->pctl);
+	}
+
+	return 0;
+}
+
+static int ocelot_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ocelot_pinctrl *info = gpiochip_get_data(chip);
+	unsigned int val;
+
+	regmap_read(info->map, OCELOT_GPIO_IN, &val);
+
+	return !!(val & BIT(offset));
+}
+
+static void ocelot_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			    int value)
+{
+	struct ocelot_pinctrl *info = gpiochip_get_data(chip);
+
+	if (value)
+		regmap_write(info->map, OCELOT_GPIO_OUT_SET, BIT(offset));
+	else
+		regmap_write(info->map, OCELOT_GPIO_OUT_CLR, BIT(offset));
+}
+
+static int ocelot_gpio_get_direction(struct gpio_chip *chip,
+				     unsigned int offset)
+{
+	struct ocelot_pinctrl *info = gpiochip_get_data(chip);
+	unsigned int val;
+
+	regmap_read(info->map, OCELOT_GPIO_OE, &val);
+
+	return !(val & BIT(offset));
+}
+
+static int ocelot_gpio_direction_input(struct gpio_chip *chip,
+				       unsigned int offset)
+{
+	return pinctrl_gpio_direction_input(chip->base + offset);
+}
+
+static int ocelot_gpio_direction_output(struct gpio_chip *chip,
+					unsigned int offset, int value)
+{
+	struct ocelot_pinctrl *info = gpiochip_get_data(chip);
+	unsigned int pin = BIT(offset);
+
+	if (value)
+		regmap_write(info->map, OCELOT_GPIO_OUT_SET, pin);
+	else
+		regmap_write(info->map, OCELOT_GPIO_OUT_CLR, pin);
+
+	return pinctrl_gpio_direction_output(chip->base + offset);
+}
+
+static const struct gpio_chip ocelot_gpiolib_chip = {
+	.request = gpiochip_generic_request,
+	.free = gpiochip_generic_free,
+	.set = ocelot_gpio_set,
+	.get = ocelot_gpio_get,
+	.get_direction = ocelot_gpio_get_direction,
+	.direction_input = ocelot_gpio_direction_input,
+	.direction_output = ocelot_gpio_direction_output,
+	.owner = THIS_MODULE,
+};
+
+static int ocelot_gpiochip_register(struct platform_device *pdev,
+				    struct ocelot_pinctrl *info)
+{
+	struct gpio_chip *gc;
+	int ret;
+
+	info->gpio_chip = ocelot_gpiolib_chip;
+
+	gc = &info->gpio_chip;
+	gc->ngpio = OCELOT_PINS;
+	gc->parent = &pdev->dev;
+	gc->base = 0;
+	gc->of_node = info->dev->of_node;
+	gc->label = "ocelot-gpio";
+
+	ret = devm_gpiochip_add_data(&pdev->dev, gc, info);
+	if (ret)
+		return ret;
+
+	/* TODO: this can be used as an irqchip but no board is using that */
+
+	return 0;
+}
+
+static const struct regmap_config ocelot_pinctrl_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0x64,
+};
+
+static const struct of_device_id ocelot_pinctrl_of_match[] = {
+	{ .compatible = "mscc,ocelot-pinctrl" },
+	{},
+};
+
+int ocelot_pinctrl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ocelot_pinctrl *info;
+	void __iomem *base;
+	int ret;
+
+	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	base = devm_ioremap_resource(dev,
+			platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	if (IS_ERR(base)) {
+		dev_err(dev, "Failed to ioremap registers\n");
+		return PTR_ERR(base);
+	}
+
+	info->map = devm_regmap_init_mmio(dev, base,
+					  &ocelot_pinctrl_regmap_config);
+	if (IS_ERR(info->map)) {
+		dev_err(dev, "Failed to create regmap\n");
+		return PTR_ERR(info->map);
+	}
+	dev_set_drvdata(dev, info->map);
+	info->dev = dev;
+
+	ret = ocelot_pinctrl_register(pdev, info);
+	if (ret)
+		return ret;
+
+	ret = ocelot_gpiochip_register(pdev, info);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static struct platform_driver ocelot_pinctrl_driver = {
+	.driver = {
+		.name = "pinctrl-ocelot",
+		.of_match_table = of_match_ptr(ocelot_pinctrl_of_match),
+		.suppress_bind_attrs = true,
+	},
+	.probe = ocelot_pinctrl_probe,
+};
+builtin_platform_driver(ocelot_pinctrl_driver);