pinctrl: at91: add pinctrl driver

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

Each SoC will have to describe the its limitation and pin
configuration via device tree. This will allow to do not need
to touch the C code when adding new SoC if the IP version is
supported.

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

3 files changed, 468 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 9d0f501..355aeae 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -150,6 +150,20 @@ config ROCKCHIP_RK3288_PINCTRL
 	  definitions and pin control functions for each available multiplex
 	  function.
 
+config PINCTRL_AT91
+	bool "AT91 pinctrl driver"
+	depends on DM
+	help
+	  This option is to enable the AT91 pinctrl driver for AT91 PIO
+	  controller. AT91 PIO controller is a combined gpio-controller,
+	  pin-mux and pin-config module. Each I/O pin may be dedicated as
+	  a general-purpose I/O or be assigned to a function of an embedded
+	  peripheral. Each I/O pin has a glitch filter providing rejection of
+	  glitches lower than one-half of peripheral clock cycle and
+	  a debouncing filter providing rejection of unwanted pulses from key
+	  or push button operations. You can also control the multi-driver
+	  capability, pull-up and pull-down feature on each I/O pin.
+
 config PINCTRL_AT91PIO4
 	bool "AT91 PIO4 pinctrl driver"
 	depends on DM
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 2ac9c19..bbb2480 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-$(CONFIG_PINCTRL_AT91)		+= pinctrl-at91.o
 obj-$(CONFIG_PINCTRL_AT91PIO4)		+= pinctrl-at91-pio4.o
 obj-y					+= nxp/
 obj-$(CONFIG_ARCH_ATH79) += ath79/
diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
new file mode 100644
index 0000000..904e1bd
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-at91.c
@@ -0,0 +1,453 @@
+/*
+ * Atmel PIO 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/at91_pio.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define MAX_GPIO_BANKS		5
+#define MAX_NB_GPIO_PER_BANK	32
+
+#define MAX_PINMUX_ENTRIES	200
+
+struct at91_pinctrl_priv {
+	struct at91_port *reg_base[MAX_GPIO_BANKS];
+	u32 nbanks;
+};
+
+#define PULL_UP			BIT(0)
+#define MULTI_DRIVE		BIT(1)
+#define DEGLITCH		BIT(2)
+#define PULL_DOWN		BIT(3)
+#define DIS_SCHMIT		BIT(4)
+#define DRIVE_STRENGTH_SHIFT	5
+#define DRIVE_STRENGTH_MASK	0x3
+#define DRIVE_STRENGTH		(DRIVE_STRENGTH_MASK << DRIVE_STRENGTH_SHIFT)
+#define OUTPUT			BIT(7)
+#define OUTPUT_VAL_SHIFT	8
+#define OUTPUT_VAL		(0x1 << OUTPUT_VAL_SHIFT)
+#define DEBOUNCE		BIT(16)
+#define DEBOUNCE_VAL_SHIFT	17
+#define DEBOUNCE_VAL		(0x3fff << DEBOUNCE_VAL_SHIFT)
+
+/**
+ * These defines will translated the dt binding settings to our internal
+ * settings. They are not necessarily the same value as the register setting.
+ * The actual drive strength current of low, medium and high must be looked up
+ * from the corresponding device datasheet. This value is different for pins
+ * that are even in the same banks. It is also dependent on VCC.
+ * DRIVE_STRENGTH_DEFAULT is just a placeholder to avoid changing the drive
+ * strength when there is no dt config for it.
+ */
+#define DRIVE_STRENGTH_DEFAULT	(0 << DRIVE_STRENGTH_SHIFT)
+#define DRIVE_STRENGTH_LOW	(1 << DRIVE_STRENGTH_SHIFT)
+#define DRIVE_STRENGTH_MED	(2 << DRIVE_STRENGTH_SHIFT)
+#define DRIVE_STRENGTH_HI	(3 << DRIVE_STRENGTH_SHIFT)
+
+enum at91_mux {
+	AT91_MUX_GPIO = 0,
+	AT91_MUX_PERIPH_A = 1,
+	AT91_MUX_PERIPH_B = 2,
+	AT91_MUX_PERIPH_C = 3,
+	AT91_MUX_PERIPH_D = 4,
+};
+
+/**
+ * struct at91_pinctrl_mux_ops - describes an AT91 mux ops group
+ * on new IP with support for periph C and D the way to mux in
+ * periph A and B has changed
+ * So provide the right callbacks
+ * if not present means the IP does not support it
+ * @mux_A_periph: assign the corresponding pin to the peripheral A function.
+ * @mux_B_periph: assign the corresponding pin to the peripheral B function.
+ * @mux_C_periph: assign the corresponding pin to the peripheral C function.
+ * @mux_D_periph: assign the corresponding pin to the peripheral D function.
+ * @set_deglitch: enable/disable the deglitch feature.
+ * @set_debounce: enable/disable the debounce feature.
+ * @set_pulldown: enable/disable the pulldown feature.
+ * @disable_schmitt_trig: disable schmitt trigger
+ */
+struct at91_pinctrl_mux_ops {
+	void (*mux_A_periph)(struct at91_port *pio, u32 mask);
+	void (*mux_B_periph)(struct at91_port *pio, u32 mask);
+	void (*mux_C_periph)(struct at91_port *pio, u32 mask);
+	void (*mux_D_periph)(struct at91_port *pio, u32 mask);
+	void (*set_deglitch)(struct at91_port *pio, u32 mask, bool is_on);
+	void (*set_debounce)(struct at91_port *pio, u32 mask, bool is_on,
+			     u32 div);
+	void (*set_pulldown)(struct at91_port *pio, u32 mask, bool is_on);
+	void (*disable_schmitt_trig)(struct at91_port *pio, u32 mask);
+	void (*set_drivestrength)(struct at91_port *pio, u32 pin,
+				  u32 strength);
+};
+
+static u32 two_bit_pin_value_shift_amount(u32 pin)
+{
+	/* return the shift value for a pin for "two bit" per pin registers,
+	 * i.e. drive strength */
+	return 2 * ((pin >= MAX_NB_GPIO_PER_BANK/2)
+			? pin - MAX_NB_GPIO_PER_BANK/2 : pin);
+}
+
+static void at91_mux_disable_interrupt(struct at91_port *pio, u32 mask)
+{
+	writel(mask, &pio->idr);
+}
+
+static void at91_mux_set_pullup(struct at91_port *pio, u32 mask, bool on)
+{
+	if (on)
+		writel(mask, &pio->mux.pio3.ppddr);
+
+	writel(mask, (on ? &pio->puer : &pio->pudr));
+}
+
+static void at91_mux_set_output(struct at91_port *pio, unsigned mask,
+				bool is_on, bool val)
+{
+	writel(mask, (val ? &pio->sodr : &pio->codr));
+	writel(mask, (is_on ? &pio->oer : &pio->odr));
+}
+
+static void at91_mux_set_multidrive(struct at91_port *pio, u32 mask, bool on)
+{
+	writel(mask, (on ? &pio->mder : &pio->mddr));
+}
+
+static void at91_mux_set_A_periph(struct at91_port *pio, u32 mask)
+{
+	writel(mask, &pio->mux.pio2.asr);
+}
+
+static void at91_mux_set_B_periph(struct at91_port *pio, u32 mask)
+{
+	writel(mask, &pio->mux.pio2.bsr);
+}
+
+static void at91_mux_pio3_set_A_periph(struct at91_port *pio, u32 mask)
+{
+	writel(readl(&pio->mux.pio3.abcdsr1) & ~mask, &pio->mux.pio3.abcdsr1);
+	writel(readl(&pio->mux.pio3.abcdsr2) & ~mask, &pio->mux.pio3.abcdsr2);
+}
+
+static void at91_mux_pio3_set_B_periph(struct at91_port *pio, u32 mask)
+{
+	writel(readl(&pio->mux.pio3.abcdsr1) | mask, &pio->mux.pio3.abcdsr1);
+	writel(readl(&pio->mux.pio3.abcdsr2) & ~mask, &pio->mux.pio3.abcdsr2);
+}
+
+static void at91_mux_pio3_set_C_periph(struct at91_port *pio, u32 mask)
+{
+	writel(readl(&pio->mux.pio3.abcdsr1) & ~mask, &pio->mux.pio3.abcdsr1);
+	writel(readl(&pio->mux.pio3.abcdsr2) | mask, &pio->mux.pio3.abcdsr2);
+}
+
+static void at91_mux_pio3_set_D_periph(struct at91_port *pio, u32 mask)
+{
+	writel(readl(&pio->mux.pio3.abcdsr1) | mask, &pio->mux.pio3.abcdsr1);
+	writel(readl(&pio->mux.pio3.abcdsr2) | mask, &pio->mux.pio3.abcdsr2);
+}
+
+static void at91_mux_set_deglitch(struct at91_port *pio, u32 mask, bool is_on)
+{
+	writel(mask, (is_on ? &pio->ifer : &pio->ifdr));
+}
+
+static void at91_mux_pio3_set_deglitch(struct at91_port *pio,
+				       u32 mask, bool is_on)
+{
+	if (is_on)
+		writel(mask, &pio->mux.pio3.ifscdr);
+	at91_mux_set_deglitch(pio, mask, is_on);
+}
+
+static void at91_mux_pio3_set_debounce(struct at91_port *pio, u32 mask,
+				       bool is_on, u32 div)
+{
+	if (is_on) {
+		writel(mask, &pio->mux.pio3.ifscer);
+		writel(div & PIO_SCDR_DIV, &pio->mux.pio3.scdr);
+		writel(mask, &pio->ifer);
+	} else {
+		writel(mask, &pio->mux.pio3.ifscdr);
+	}
+}
+
+static void at91_mux_pio3_set_pulldown(struct at91_port *pio,
+				       u32 mask, bool is_on)
+{
+	if (is_on)
+		writel(mask, &pio->pudr);
+
+	writel(mask, (is_on ? &pio->mux.pio3.ppder : &pio->mux.pio3.ppddr));
+}
+
+static void at91_mux_pio3_disable_schmitt_trig(struct at91_port *pio,
+					       u32 mask)
+{
+	writel(readl(&pio->schmitt) | mask, &pio->schmitt);
+}
+
+static void set_drive_strength(void *reg, u32 pin, u32 strength)
+{
+	u32 shift = two_bit_pin_value_shift_amount(pin);
+
+	clrsetbits_le32(reg, DRIVE_STRENGTH_MASK << shift, strength << shift);
+}
+
+static void at91_mux_sama5d3_set_drivestrength(struct at91_port *pio,
+					       u32 pin, u32 setting)
+{
+	void *reg;
+
+	reg = &pio->driver12;
+	if (pin >= MAX_NB_GPIO_PER_BANK / 2)
+		reg = &pio->driver2;
+
+	/* do nothing if setting is zero */
+	if (!setting)
+		return;
+
+	/* strength is 1 to 1 with setting for SAMA5 */
+	set_drive_strength(reg, pin, setting);
+}
+
+static void at91_mux_sam9x5_set_drivestrength(struct at91_port *pio,
+					      u32 pin, u32 setting)
+{
+	void *reg;
+
+	reg = &pio->driver1;
+	if (pin >= MAX_NB_GPIO_PER_BANK / 2)
+		reg = &pio->driver12;
+
+	/* do nothing if setting is zero */
+	if (!setting)
+		return;
+
+	/* strength is inverse on SAM9x5s with our defines
+	 * 0 = hi, 1 = med, 2 = low, 3 = rsvd */
+	setting = DRIVE_STRENGTH_HI - setting;
+
+	set_drive_strength(reg, pin, setting);
+}
+
+static struct at91_pinctrl_mux_ops at91rm9200_ops = {
+	.mux_A_periph	= at91_mux_set_A_periph,
+	.mux_B_periph	= at91_mux_set_B_periph,
+	.set_deglitch	= at91_mux_set_deglitch,
+};
+
+static struct at91_pinctrl_mux_ops at91sam9x5_ops = {
+	.mux_A_periph	= at91_mux_pio3_set_A_periph,
+	.mux_B_periph	= at91_mux_pio3_set_B_periph,
+	.mux_C_periph	= at91_mux_pio3_set_C_periph,
+	.mux_D_periph	= at91_mux_pio3_set_D_periph,
+	.set_deglitch	= at91_mux_pio3_set_deglitch,
+	.set_debounce	= at91_mux_pio3_set_debounce,
+	.set_pulldown	= at91_mux_pio3_set_pulldown,
+	.disable_schmitt_trig = at91_mux_pio3_disable_schmitt_trig,
+	.set_drivestrength = at91_mux_sam9x5_set_drivestrength,
+};
+
+static struct at91_pinctrl_mux_ops sama5d3_ops = {
+	.mux_A_periph	= at91_mux_pio3_set_A_periph,
+	.mux_B_periph	= at91_mux_pio3_set_B_periph,
+	.mux_C_periph	= at91_mux_pio3_set_C_periph,
+	.mux_D_periph	= at91_mux_pio3_set_D_periph,
+	.set_deglitch	= at91_mux_pio3_set_deglitch,
+	.set_debounce	= at91_mux_pio3_set_debounce,
+	.set_pulldown	= at91_mux_pio3_set_pulldown,
+	.disable_schmitt_trig = at91_mux_pio3_disable_schmitt_trig,
+	.set_drivestrength = at91_mux_sama5d3_set_drivestrength,
+};
+
+static void at91_mux_gpio_disable(struct at91_port *pio, u32 mask)
+{
+	writel(mask, &pio->pdr);
+}
+
+static void at91_mux_gpio_enable(struct at91_port *pio, u32 mask, bool input)
+{
+	writel(mask, &pio->per);
+	writel(mask, (input ? &pio->odr : &pio->oer));
+}
+
+static int at91_pmx_set(struct at91_pinctrl_mux_ops *ops,
+			struct at91_port *pio, u32 mask, enum at91_mux mux)
+{
+	at91_mux_disable_interrupt(pio, mask);
+	switch (mux) {
+	case AT91_MUX_GPIO:
+		at91_mux_gpio_enable(pio, mask, 1);
+		break;
+	case AT91_MUX_PERIPH_A:
+		ops->mux_A_periph(pio, mask);
+		break;
+	case AT91_MUX_PERIPH_B:
+		ops->mux_B_periph(pio, mask);
+		break;
+	case AT91_MUX_PERIPH_C:
+		if (!ops->mux_C_periph)
+			return -EINVAL;
+		ops->mux_C_periph(pio, mask);
+		break;
+	case AT91_MUX_PERIPH_D:
+		if (!ops->mux_D_periph)
+			return -EINVAL;
+		ops->mux_D_periph(pio, mask);
+		break;
+	}
+	if (mux)
+		at91_mux_gpio_disable(pio, mask);
+
+	return 0;
+}
+
+static int at91_pinconf_set(struct at91_pinctrl_mux_ops *ops,
+			    struct at91_port *pio, u32 pin, u32 config)
+{
+	u32 mask = BIT(pin);
+
+	if ((config & PULL_UP) && (config & PULL_DOWN))
+		return -EINVAL;
+
+	at91_mux_set_output(pio, mask, config & OUTPUT,
+			    (config & OUTPUT_VAL) >> OUTPUT_VAL_SHIFT);
+	at91_mux_set_pullup(pio, mask, config & PULL_UP);
+	at91_mux_set_multidrive(pio, mask, config & MULTI_DRIVE);
+	if (ops->set_deglitch)
+		ops->set_deglitch(pio, mask, config & DEGLITCH);
+	if (ops->set_debounce)
+		ops->set_debounce(pio, mask, config & DEBOUNCE,
+			(config & DEBOUNCE_VAL) >> DEBOUNCE_VAL_SHIFT);
+	if (ops->set_pulldown)
+		ops->set_pulldown(pio, mask, config & PULL_DOWN);
+	if (ops->disable_schmitt_trig && config & DIS_SCHMIT)
+		ops->disable_schmitt_trig(pio, mask);
+	if (ops->set_drivestrength)
+		ops->set_drivestrength(pio, pin,
+			(config & DRIVE_STRENGTH) >> DRIVE_STRENGTH_SHIFT);
+
+	return 0;
+}
+
+static int at91_pin_check_config(struct udevice *dev, u32 bank, u32 pin)
+{
+	struct at91_pinctrl_priv *priv = dev_get_priv(dev);
+
+	if (bank >= priv->nbanks) {
+		debug("pin conf bank %d >= nbanks %d\n", bank, priv->nbanks);
+		return -EINVAL;
+	}
+
+	if (pin >= MAX_NB_GPIO_PER_BANK) {
+		debug("pin conf pin %d >= %d\n", pin, MAX_NB_GPIO_PER_BANK);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int at91_pinctrl_set_state(struct udevice *dev, struct udevice *config)
+{
+	struct at91_pinctrl_priv *priv = dev_get_priv(dev);
+	const void *blob = gd->fdt_blob;
+	int node = config->of_offset;
+	u32 cells[MAX_PINMUX_ENTRIES];
+	const u32 *list = cells;
+	u32 bank, pin;
+	u32 conf, mask, count, i;
+	int size;
+	int ret;
+	enum at91_mux mux;
+	struct at91_port *pio;
+	struct at91_pinctrl_mux_ops *ops =
+			(struct at91_pinctrl_mux_ops *)dev_get_driver_data(dev);
+
+	/*
+	 * the binding format is atmel,pins = <bank pin mux CONFIG ...>,
+	 * do sanity check and calculate pins number
+	 */
+	size = fdtdec_get_int_array_count(blob, node, "atmel,pins",
+					  cells, ARRAY_SIZE(cells));
+
+	/* we do not check return since it's safe node passed down */
+	count = size >> 2;
+	if (!count)
+		return -EINVAL;
+
+	for (i = 0; i < count; i++) {
+		bank = *list++;
+		pin = *list++;
+		mux = *list++;
+		conf = *list++;
+
+		ret = at91_pin_check_config(dev, bank, pin);
+		if (ret)
+			return ret;
+
+		pio = priv->reg_base[bank];
+		mask = BIT(pin);
+
+		ret = at91_pmx_set(ops, pio, mask, mux);
+		if (ret)
+			return ret;
+
+		ret = at91_pinconf_set(ops, pio, pin, conf);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+const struct pinctrl_ops at91_pinctrl_ops  = {
+	.set_state = at91_pinctrl_set_state,
+};
+
+static int at91_pinctrl_probe(struct udevice *dev)
+{
+	struct at91_pinctrl_priv *priv = dev_get_priv(dev);
+	fdt_addr_t addr_base;
+	int index;
+
+	for (index = 0; index < MAX_GPIO_BANKS; index++) {
+		addr_base = dev_get_addr_index(dev, index);
+		if (addr_base == FDT_ADDR_T_NONE)
+			break;
+
+		priv->reg_base[index] = (struct at91_port *)addr_base;
+	}
+
+	priv->nbanks = index;
+
+	return 0;
+}
+
+static const struct udevice_id at91_pinctrl_match[] = {
+	{ .compatible = "atmel,sama5d3-pinctrl", .data = (ulong)&sama5d3_ops },
+	{ .compatible = "atmel,at91sam9x5-pinctrl", .data = (ulong)&at91sam9x5_ops },
+	{ .compatible = "atmel,at91rm9200-pinctrl", .data = (ulong)&at91rm9200_ops },
+	{}
+};
+
+U_BOOT_DRIVER(at91_pinctrl) = {
+	.name = "pinctrl_at91",
+	.id = UCLASS_PINCTRL,
+	.of_match = at91_pinctrl_match,
+	.probe = at91_pinctrl_probe,
+	.priv_auto_alloc_size = sizeof(struct at91_pinctrl_priv),
+	.ops = &at91_pinctrl_ops,
+};