pinctrl: introduce driver for Atmel PIO4 controller
authorLudovic Desroches <ludovic.desroches@atmel.com>
Wed, 16 Sep 2015 15:36:57 +0000 (17:36 +0200)
committerLinus Walleij <linus.walleij@linaro.org>
Mon, 21 Sep 2015 18:21:33 +0000 (11:21 -0700)
Add a pinctrl/gpio driver for Atmel PIO4 controller available on SAMA5D2
chip family.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
drivers/pinctrl/Kconfig
drivers/pinctrl/Makefile
drivers/pinctrl/pinctrl-at91-pio4.c [new file with mode: 0644]

index 84dd2ed47a928e57effa8297597592733c703100..b422e4ed73f4266f7a8d13db4ec1096395163fc3 100644 (file)
@@ -67,6 +67,19 @@ config PINCTRL_AT91
        help
          Say Y here to enable the at91 pinctrl driver
 
+config PINCTRL_AT91PIO4
+       bool "AT91 PIO4 pinctrl driver"
+       depends on OF
+       depends on ARCH_AT91
+       select PINMUX
+       select GENERIC_PINCONF
+       select GPIOLIB
+       select GPIOLIB_IRQCHIP
+       select OF_GPIO
+       help
+         Say Y here to enable the at91 pinctrl/gpio driver for Atmel PIO4
+         controller available on sama5d2 SoC.
+
 config PINCTRL_AMD
        bool "AMD GPIO pin control"
        depends on GPIOLIB
index cad077c43fb7313af8b81bb9ca9a8a83f48e5224..8bed0c2222df05ade79881354aa5fcf093548093 100644 (file)
@@ -12,6 +12,7 @@ obj-$(CONFIG_PINCTRL_AS3722)  += pinctrl-as3722.o
 obj-$(CONFIG_PINCTRL_BF54x)    += pinctrl-adi2-bf54x.o
 obj-$(CONFIG_PINCTRL_BF60x)    += pinctrl-adi2-bf60x.o
 obj-$(CONFIG_PINCTRL_AT91)     += pinctrl-at91.o
+obj-$(CONFIG_PINCTRL_AT91PIO4) += pinctrl-at91-pio4.o
 obj-$(CONFIG_PINCTRL_AMD)      += pinctrl-amd.o
 obj-$(CONFIG_PINCTRL_DIGICOLOR)        += pinctrl-digicolor.o
 obj-$(CONFIG_PINCTRL_FALCON)   += pinctrl-falcon.o
diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
new file mode 100644 (file)
index 0000000..6aff632
--- /dev/null
@@ -0,0 +1,1017 @@
+/*
+ * Driver for the Atmel PIO4 controller
+ *
+ * Copyright (C) 2015 Atmel,
+ *               2015 Ludovic Desroches <ludovic.desroches@atmel.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/slab.h>
+#include "core.h"
+#include "pinconf.h"
+#include "pinctrl-utils.h"
+
+/*
+ * Warning:
+ * In order to not introduce confusion between Atmel PIO groups and pinctrl
+ * framework groups, Atmel PIO groups will be called banks, line is kept to
+ * designed the pin id into this bank.
+ */
+
+#define ATMEL_PIO_MSKR         0x0000
+#define ATMEL_PIO_CFGR         0x0004
+#define                ATMEL_PIO_CFGR_FUNC_MASK        GENMASK(2, 0)
+#define                ATMEL_PIO_DIR_MASK              BIT(8)
+#define                ATMEL_PIO_PUEN_MASK             BIT(9)
+#define                ATMEL_PIO_PDEN_MASK             BIT(10)
+#define                ATMEL_PIO_IFEN_MASK             BIT(12)
+#define                ATMEL_PIO_IFSCEN_MASK           BIT(13)
+#define                ATMEL_PIO_OPD_MASK              BIT(14)
+#define                ATMEL_PIO_SCHMITT_MASK          BIT(15)
+#define                ATMEL_PIO_CFGR_EVTSEL_MASK      GENMASK(26, 24)
+#define                ATMEL_PIO_CFGR_EVTSEL_FALLING   (0 << 24)
+#define                ATMEL_PIO_CFGR_EVTSEL_RISING    (1 << 24)
+#define                ATMEL_PIO_CFGR_EVTSEL_BOTH      (2 << 24)
+#define                ATMEL_PIO_CFGR_EVTSEL_LOW       (3 << 24)
+#define                ATMEL_PIO_CFGR_EVTSEL_HIGH      (4 << 24)
+#define ATMEL_PIO_PDSR         0x0008
+#define ATMEL_PIO_LOCKSR       0x000C
+#define ATMEL_PIO_SODR         0x0010
+#define ATMEL_PIO_CODR         0x0014
+#define ATMEL_PIO_ODSR         0x0018
+#define ATMEL_PIO_IER          0x0020
+#define ATMEL_PIO_IDR          0x0024
+#define ATMEL_PIO_IMR          0x0028
+#define ATMEL_PIO_ISR          0x002C
+#define ATMEL_PIO_IOFR         0x003C
+
+#define ATMEL_PIO_NPINS_PER_BANK       32
+#define ATMEL_PIO_BANK(pin_id)         (pin_id / ATMEL_PIO_NPINS_PER_BANK)
+#define ATMEL_PIO_LINE(pin_id)         (pin_id % ATMEL_PIO_NPINS_PER_BANK)
+#define ATMEL_PIO_BANK_OFFSET          0x40
+
+#define ATMEL_GET_PIN_NO(pinfunc)      ((pinfunc) & 0xff)
+#define ATMEL_GET_PIN_FUNC(pinfunc)    ((pinfunc >> 16) & 0xf)
+#define ATMEL_GET_PIN_IOSET(pinfunc)   ((pinfunc >> 20) & 0xf)
+
+struct atmel_pioctrl_data {
+       unsigned nbanks;
+};
+
+struct atmel_group {
+       const char *name;
+       u32 pin;
+};
+
+struct atmel_pin {
+       unsigned pin_id;
+       unsigned mux;
+       unsigned ioset;
+       unsigned bank;
+       unsigned line;
+       const char *device;
+};
+
+/**
+ * struct atmel_pioctrl - Atmel PIO controller (pinmux + gpio)
+ * @reg_base: base address of the controller.
+ * @clk: clock of the controller.
+ * @nbanks: number of PIO groups, it can vary depending on the SoC.
+ * @pinctrl_dev: pinctrl device registered.
+ * @groups: groups table to provide group name and pin in the group to pinctrl.
+ * @group_names: group names table to provide all the group/pin names to
+ *     pinctrl or gpio.
+ * @pins: pins table used for both pinctrl and gpio. pin_id, bank and line
+ *     fields are set at probe time. Other ones are set when parsing dt
+ *     pinctrl.
+ * @npins: number of pins.
+ * @gpio_chip: gpio chip registered.
+ * @irq_domain: irq domain for the gpio controller.
+ * @irqs: table containing the hw irq number of the bank. The index of the
+ *     table is the bank id.
+ * @dev: device entry for the Atmel PIO controller.
+ * @node: node of the Atmel PIO controller.
+ */
+struct atmel_pioctrl {
+       void __iomem            *reg_base;
+       struct clk              *clk;
+       unsigned                nbanks;
+       struct pinctrl_dev      *pinctrl_dev;
+       struct atmel_group      *groups;
+       const char * const      *group_names;
+       struct atmel_pin        **pins;
+       unsigned                npins;
+       struct gpio_chip        *gpio_chip;
+       struct irq_domain       *irq_domain;
+       int                     *irqs;
+       struct device           *dev;
+       struct device_node      *node;
+};
+
+static const char * const atmel_functions[] = {
+       "GPIO", "A", "B", "C", "D", "E", "F", "G"
+};
+
+/* --- GPIO --- */
+static unsigned int atmel_gpio_read(struct atmel_pioctrl *atmel_pioctrl,
+                                   unsigned int bank, unsigned int reg)
+{
+       return readl_relaxed(atmel_pioctrl->reg_base
+                            + ATMEL_PIO_BANK_OFFSET * bank + reg);
+}
+
+static void atmel_gpio_write(struct atmel_pioctrl *atmel_pioctrl,
+                            unsigned int bank, unsigned int reg,
+                            unsigned int val)
+{
+       writel_relaxed(val, atmel_pioctrl->reg_base
+                      + ATMEL_PIO_BANK_OFFSET * bank + reg);
+}
+
+static void atmel_gpio_irq_ack(struct irq_data *d)
+{
+       /*
+        * Nothing to do, interrupt is cleared when reading the status
+        * register.
+        */
+}
+
+static int atmel_gpio_irq_set_type(struct irq_data *d, unsigned type)
+{
+       struct atmel_pioctrl *atmel_pioctrl = irq_data_get_irq_chip_data(d);
+       struct atmel_pin *pin = atmel_pioctrl->pins[d->hwirq];
+       unsigned reg;
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_MSKR,
+                        BIT(pin->line));
+       reg = atmel_gpio_read(atmel_pioctrl, pin->bank, ATMEL_PIO_CFGR);
+       reg &= (~ATMEL_PIO_CFGR_EVTSEL_MASK);
+
+       switch (type) {
+       case IRQ_TYPE_EDGE_RISING:
+               __irq_set_handler_locked(d->irq, handle_edge_irq);
+               reg |= ATMEL_PIO_CFGR_EVTSEL_RISING;
+               break;
+       case IRQ_TYPE_EDGE_FALLING:
+               __irq_set_handler_locked(d->irq, handle_edge_irq);
+               reg |= ATMEL_PIO_CFGR_EVTSEL_FALLING;
+               break;
+       case IRQ_TYPE_EDGE_BOTH:
+               __irq_set_handler_locked(d->irq, handle_edge_irq);
+               reg |= ATMEL_PIO_CFGR_EVTSEL_BOTH;
+               break;
+       case IRQ_TYPE_LEVEL_LOW:
+               __irq_set_handler_locked(d->irq, handle_level_irq);
+               reg |= ATMEL_PIO_CFGR_EVTSEL_LOW;
+               break;
+       case IRQ_TYPE_LEVEL_HIGH:
+               __irq_set_handler_locked(d->irq, handle_level_irq);
+               reg |= ATMEL_PIO_CFGR_EVTSEL_HIGH;
+               break;
+       case IRQ_TYPE_NONE:
+       default:
+               return -EINVAL;
+       }
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_CFGR, reg);
+
+       return 0;
+}
+
+static void atmel_gpio_irq_mask(struct irq_data *d)
+{
+       struct atmel_pioctrl *atmel_pioctrl = irq_data_get_irq_chip_data(d);
+       struct atmel_pin *pin = atmel_pioctrl->pins[d->hwirq];
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_IDR,
+                        BIT(pin->line));
+}
+
+static void atmel_gpio_irq_unmask(struct irq_data *d)
+{
+       struct atmel_pioctrl *atmel_pioctrl = irq_data_get_irq_chip_data(d);
+       struct atmel_pin *pin = atmel_pioctrl->pins[d->hwirq];
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_IER,
+                        BIT(pin->line));
+}
+
+static struct irq_chip atmel_gpio_irq_chip = {
+       .name           = "GPIO",
+       .irq_ack        = atmel_gpio_irq_ack,
+       .irq_mask       = atmel_gpio_irq_mask,
+       .irq_unmask     = atmel_gpio_irq_unmask,
+       .irq_set_type   = atmel_gpio_irq_set_type,
+};
+
+static void atmel_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+       struct atmel_pioctrl *atmel_pioctrl = irq_get_handler_data(irq);
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       unsigned long isr;
+       int n, bank = -1;
+
+       /* Find from which bank is the irq received. */
+       for (n = 0; n < atmel_pioctrl->nbanks; n++) {
+               if (atmel_pioctrl->irqs[n] == irq) {
+                       bank = n;
+                       break;
+               }
+       }
+
+       if (bank < 0) {
+               dev_err(atmel_pioctrl->dev,
+                       "no bank associated to irq %u\n", irq);
+               return;
+       }
+
+       chained_irq_enter(chip, desc);
+
+       for (;;) {
+               isr = (unsigned long)atmel_gpio_read(atmel_pioctrl, bank,
+                                                    ATMEL_PIO_ISR);
+               isr &= (unsigned long)atmel_gpio_read(atmel_pioctrl, bank,
+                                                     ATMEL_PIO_IMR);
+               if (!isr)
+                       break;
+
+               for_each_set_bit(n, &isr, BITS_PER_LONG)
+                       generic_handle_irq(gpio_to_irq(bank *
+                                       ATMEL_PIO_NPINS_PER_BANK + n));
+       }
+
+       chained_irq_exit(chip, desc);
+}
+
+static int atmel_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+       struct atmel_pioctrl *atmel_pioctrl = dev_get_drvdata(chip->dev);
+       struct atmel_pin *pin = atmel_pioctrl->pins[offset];
+       unsigned reg;
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_MSKR,
+                        BIT(pin->line));
+       reg = atmel_gpio_read(atmel_pioctrl, pin->bank, ATMEL_PIO_CFGR);
+       reg &= ~ATMEL_PIO_DIR_MASK;
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_CFGR, reg);
+
+       return 0;
+}
+
+static int atmel_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+       struct atmel_pioctrl *atmel_pioctrl = dev_get_drvdata(chip->dev);
+       struct atmel_pin *pin = atmel_pioctrl->pins[offset];
+       unsigned reg;
+
+       reg = atmel_gpio_read(atmel_pioctrl, pin->bank, ATMEL_PIO_PDSR);
+
+       return !!(reg & BIT(pin->line));
+}
+
+static int atmel_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+                                      int value)
+{
+       struct atmel_pioctrl *atmel_pioctrl = dev_get_drvdata(chip->dev);
+       struct atmel_pin *pin = atmel_pioctrl->pins[offset];
+       unsigned reg;
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank,
+                        value ? ATMEL_PIO_SODR : ATMEL_PIO_CODR,
+                        BIT(pin->line));
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_MSKR,
+                        BIT(pin->line));
+       reg = atmel_gpio_read(atmel_pioctrl, pin->bank, ATMEL_PIO_CFGR);
+       reg |= ATMEL_PIO_DIR_MASK;
+       atmel_gpio_write(atmel_pioctrl, pin->bank, ATMEL_PIO_CFGR, reg);
+
+       return 0;
+}
+
+static void atmel_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+       struct atmel_pioctrl *atmel_pioctrl = dev_get_drvdata(chip->dev);
+       struct atmel_pin *pin = atmel_pioctrl->pins[offset];
+
+       atmel_gpio_write(atmel_pioctrl, pin->bank,
+                        val ? ATMEL_PIO_SODR : ATMEL_PIO_CODR,
+                        BIT(pin->line));
+}
+
+static int atmel_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+       struct atmel_pioctrl *atmel_pioctrl = dev_get_drvdata(chip->dev);
+
+       return irq_find_mapping(atmel_pioctrl->irq_domain, offset);
+}
+
+static struct gpio_chip atmel_gpio_chip = {
+       .direction_input        = atmel_gpio_direction_input,
+       .get                    = atmel_gpio_get,
+       .direction_output       = atmel_gpio_direction_output,
+       .set                    = atmel_gpio_set,
+       .to_irq                 = atmel_gpio_to_irq,
+       .base                   = 0,
+};
+
+/* --- PINCTRL --- */
+static unsigned int atmel_pin_config_read(struct pinctrl_dev *pctldev,
+                                         unsigned pin_id)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       unsigned bank = atmel_pioctrl->pins[pin_id]->bank;
+       unsigned line = atmel_pioctrl->pins[pin_id]->line;
+       void __iomem *addr = atmel_pioctrl->reg_base
+                            + bank * ATMEL_PIO_BANK_OFFSET;
+
+       writel_relaxed(BIT(line), addr + ATMEL_PIO_MSKR);
+       /* Have to set MSKR first, to access the right pin CFGR. */
+       wmb();
+
+       return readl_relaxed(addr + ATMEL_PIO_CFGR);
+}
+
+static void atmel_pin_config_write(struct pinctrl_dev *pctldev,
+                                  unsigned pin_id, u32 conf)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       unsigned bank = atmel_pioctrl->pins[pin_id]->bank;
+       unsigned line = atmel_pioctrl->pins[pin_id]->line;
+       void __iomem *addr = atmel_pioctrl->reg_base
+                            + bank * ATMEL_PIO_BANK_OFFSET;
+
+       writel_relaxed(BIT(line), addr + ATMEL_PIO_MSKR);
+       /* Have to set MSKR first, to access the right pin CFGR. */
+       wmb();
+       writel_relaxed(conf, addr + ATMEL_PIO_CFGR);
+}
+
+static int atmel_pctl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+
+       return atmel_pioctrl->npins;
+}
+
+static const char *atmel_pctl_get_group_name(struct pinctrl_dev *pctldev,
+                                            unsigned selector)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+
+       return atmel_pioctrl->groups[selector].name;
+}
+
+static int atmel_pctl_get_group_pins(struct pinctrl_dev *pctldev,
+                                    unsigned selector, const unsigned **pins,
+                                    unsigned *num_pins)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+
+       *pins = (unsigned *)&atmel_pioctrl->groups[selector].pin;
+       *num_pins = 1;
+
+       return 0;
+}
+
+struct atmel_group *atmel_pctl_find_group_by_pin(struct pinctrl_dev *pctldev,
+                                                unsigned pin)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       int i;
+
+       for (i = 0; i < atmel_pioctrl->npins; i++) {
+               struct atmel_group *grp = atmel_pioctrl->groups + i;
+
+               if (grp->pin == pin)
+                       return grp;
+       }
+
+       return NULL;
+}
+
+static int atmel_pctl_xlate_pinfunc(struct pinctrl_dev *pctldev,
+                                   struct device_node *np,
+                                   u32 pinfunc, const char **grp_name,
+                                   const char **func_name)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       unsigned pin_id, func_id;
+       struct atmel_group *grp;
+
+       pin_id = ATMEL_GET_PIN_NO(pinfunc);
+       func_id = ATMEL_GET_PIN_FUNC(pinfunc);
+
+       if (func_id >= ARRAY_SIZE(atmel_functions))
+               return -EINVAL;
+
+       *func_name = atmel_functions[func_id];
+
+       grp = atmel_pctl_find_group_by_pin(pctldev, pin_id);
+       if (!grp)
+               return -EINVAL;
+       *grp_name = grp->name;
+
+       atmel_pioctrl->pins[pin_id]->mux = func_id;
+       atmel_pioctrl->pins[pin_id]->ioset = ATMEL_GET_PIN_IOSET(pinfunc);
+       /* Want the device name not the group one. */
+       if (np->parent == atmel_pioctrl->node)
+               atmel_pioctrl->pins[pin_id]->device = np->name;
+       else
+               atmel_pioctrl->pins[pin_id]->device = np->parent->name;
+
+       return 0;
+}
+
+static int atmel_pctl_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+                                       struct device_node *np,
+                                       struct pinctrl_map **map,
+                                       unsigned *reserved_maps,
+                                       unsigned *num_maps)
+{
+       unsigned num_pins, num_configs, reserve;
+       unsigned long *configs;
+       struct property *pins;
+       bool has_config;
+       u32 pinfunc;
+       int ret, i;
+
+       pins = of_find_property(np, "pinmux", NULL);
+       if (!pins)
+               return -EINVAL;
+
+       ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
+                                             &num_configs);
+       if (ret < 0) {
+               dev_err(pctldev->dev, "%s: could not parse node property\n",
+                       of_node_full_name(np));
+               return ret;
+       }
+
+       if (num_configs)
+               has_config = true;
+
+       num_pins = pins->length / sizeof(u32);
+       if (!num_pins) {
+               dev_err(pctldev->dev, "no pins found in node %s\n",
+                       of_node_full_name(np));
+               return -EINVAL;
+       }
+
+       /*
+        * Reserve maps, at least there is a mux map and an optional conf
+        * map for each pin.
+        */
+       reserve = 1;
+       if (has_config && num_pins >= 1)
+               reserve++;
+       reserve *= num_pins;
+       ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps, num_maps,
+                                       reserve);
+       if (ret < 0)
+               return ret;
+
+       for (i = 0; i < num_pins; i++) {
+               const char *group, *func;
+
+               ret = of_property_read_u32_index(np, "pinmux", i, &pinfunc);
+               if (ret)
+                       return ret;
+
+               ret = atmel_pctl_xlate_pinfunc(pctldev, np, pinfunc, &group,
+                                              &func);
+               if (ret)
+                       return ret;
+
+               pinctrl_utils_add_map_mux(pctldev, map, reserved_maps, num_maps,
+                                         group, func);
+
+               if (has_config) {
+                       ret = pinctrl_utils_add_map_configs(pctldev, map,
+                                       reserved_maps, num_maps, group,
+                                       configs, num_configs,
+                                       PIN_MAP_TYPE_CONFIGS_GROUP);
+                       if (ret < 0)
+                               return ret;
+               }
+       }
+
+       return 0;
+}
+
+static int atmel_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
+                                    struct device_node *np_config,
+                                    struct pinctrl_map **map,
+                                    unsigned *num_maps)
+{
+       struct device_node *np;
+       unsigned reserved_maps;
+       int ret;
+
+       *map = NULL;
+       *num_maps = 0;
+       reserved_maps = 0;
+
+       /*
+        * If all the pins of a device have the same configuration (or no one),
+        * it is useless to add a subnode, so directly parse node referenced by
+        * phandle.
+        */
+       ret = atmel_pctl_dt_subnode_to_map(pctldev, np_config, map,
+                                          &reserved_maps, num_maps);
+       if (ret) {
+               for_each_child_of_node(np_config, np) {
+                       ret = atmel_pctl_dt_subnode_to_map(pctldev, np, map,
+                                                   &reserved_maps, num_maps);
+                       if (ret < 0)
+                               break;
+               }
+       }
+
+       if (ret < 0) {
+               pinctrl_utils_dt_free_map(pctldev, *map, *num_maps);
+               dev_err(pctldev->dev, "can't create maps for node %s\n",
+                       np_config->full_name);
+       }
+
+       return ret;
+}
+
+static const struct pinctrl_ops atmel_pctlops = {
+       .get_groups_count       = atmel_pctl_get_groups_count,
+       .get_group_name         = atmel_pctl_get_group_name,
+       .get_group_pins         = atmel_pctl_get_group_pins,
+       .dt_node_to_map         = atmel_pctl_dt_node_to_map,
+       .dt_free_map            = pinctrl_utils_dt_free_map,
+};
+
+static int atmel_pmx_get_functions_count(struct pinctrl_dev *pctldev)
+{
+       return ARRAY_SIZE(atmel_functions);
+}
+
+static const char *atmel_pmx_get_function_name(struct pinctrl_dev *pctldev,
+                                              unsigned selector)
+{
+       return atmel_functions[selector];
+}
+
+static int atmel_pmx_get_function_groups(struct pinctrl_dev *pctldev,
+                                        unsigned selector,
+                                        const char * const **groups,
+                                        unsigned * const num_groups)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+
+       *groups = atmel_pioctrl->group_names;
+       *num_groups = atmel_pioctrl->npins;
+
+       return 0;
+}
+
+static int atmel_pmx_set_mux(struct pinctrl_dev *pctldev,
+                            unsigned function,
+                            unsigned group)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       unsigned pin;
+       u32 conf;
+
+       dev_dbg(pctldev->dev, "enable function %s group %s\n",
+               atmel_functions[function], atmel_pioctrl->groups[group].name);
+
+       pin = atmel_pioctrl->groups[group].pin;
+       conf = atmel_pin_config_read(pctldev, pin);
+       conf &= (~ATMEL_PIO_CFGR_FUNC_MASK);
+       conf |= (function & ATMEL_PIO_CFGR_FUNC_MASK);
+       dev_dbg(pctldev->dev, "pin: %u, conf: 0x%08x\n", pin, conf);
+       atmel_pin_config_write(pctldev, pin, conf);
+
+       return 0;
+}
+
+static const struct pinmux_ops atmel_pmxops = {
+       .get_functions_count    = atmel_pmx_get_functions_count,
+       .get_function_name      = atmel_pmx_get_function_name,
+       .get_function_groups    = atmel_pmx_get_function_groups,
+       .set_mux                = atmel_pmx_set_mux,
+};
+
+static int atmel_conf_pin_config_group_get(struct pinctrl_dev *pctldev,
+                                          unsigned group,
+                                          unsigned long *config)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       unsigned param = pinconf_to_config_param(*config), arg = 0;
+       struct atmel_group *grp = atmel_pioctrl->groups + group;
+       unsigned pin_id = grp->pin;
+       u32 res;
+
+       res = atmel_pin_config_read(pctldev, pin_id);
+
+       switch (param) {
+       case PIN_CONFIG_BIAS_PULL_UP:
+               if (!(res & ATMEL_PIO_PUEN_MASK))
+                       return -EINVAL;
+               arg = 1;
+               break;
+       case PIN_CONFIG_BIAS_PULL_DOWN:
+               if ((res & ATMEL_PIO_PUEN_MASK) ||
+                   (!(res & ATMEL_PIO_PDEN_MASK)))
+                       return -EINVAL;
+               arg = 1;
+               break;
+       case PIN_CONFIG_BIAS_DISABLE:
+               if ((res & ATMEL_PIO_PUEN_MASK) ||
+                   ((res & ATMEL_PIO_PDEN_MASK)))
+                       return -EINVAL;
+               arg = 1;
+               break;
+       case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+               if (!(res & ATMEL_PIO_OPD_MASK))
+                       return -EINVAL;
+               arg = 1;
+               break;
+       case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+               if (!(res & ATMEL_PIO_SCHMITT_MASK))
+                       return -EINVAL;
+               arg = 1;
+               break;
+       default:
+               return -ENOTSUPP;
+       }
+
+       *config = pinconf_to_config_packed(param, arg);
+       return 0;
+}
+
+static int atmel_conf_pin_config_group_set(struct pinctrl_dev *pctldev,
+                                          unsigned group,
+                                          unsigned long *configs,
+                                          unsigned num_configs)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       struct atmel_group *grp = atmel_pioctrl->groups + group;
+       unsigned bank, pin, pin_id = grp->pin;
+       u32 mask, conf = 0;
+       int i;
+
+       conf = atmel_pin_config_read(pctldev, pin_id);
+
+       for (i = 0; i < num_configs; i++) {
+               unsigned param = pinconf_to_config_param(configs[i]);
+               unsigned arg = pinconf_to_config_argument(configs[i]);
+
+               dev_dbg(pctldev->dev, "%s: pin=%u, config=0x%lx\n",
+                       __func__, pin_id, configs[i]);
+
+               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 {
+                               /*
+                                * We don't care about the debounce value for several reasons:
+                                * - can't have different debounce periods inside a same group,
+                                * - the register to configure this period is a secure register.
+                                * The debouncing filter can filter a pulse with a duration of less
+                                * than 1/2 slow clock period.
+                                */
+                               conf |= ATMEL_PIO_IFEN_MASK;
+                               conf |= ATMEL_PIO_IFSCEN_MASK;
+                       }
+                       break;
+               case PIN_CONFIG_OUTPUT:
+                       conf |= ATMEL_PIO_DIR_MASK;
+                       bank = ATMEL_PIO_BANK(pin_id);
+                       pin = ATMEL_PIO_LINE(pin_id);
+                       mask = 1 << pin;
+
+                       if (arg == 0) {
+                               writel_relaxed(mask, atmel_pioctrl->reg_base +
+                                       bank * ATMEL_PIO_BANK_OFFSET +
+                                       ATMEL_PIO_CODR);
+                       } else {
+                               writel_relaxed(mask, atmel_pioctrl->reg_base +
+                                       bank * ATMEL_PIO_BANK_OFFSET +
+                                       ATMEL_PIO_SODR);
+                       }
+                       break;
+               default:
+                       dev_warn(pctldev->dev,
+                                "unsupported configuration parameter: %u\n",
+                                param);
+                       continue;
+               }
+       }
+
+       dev_dbg(pctldev->dev, "%s: reg=0x%08x\n", __func__, conf);
+       atmel_pin_config_write(pctldev, pin_id, conf);
+
+       return 0;
+}
+
+static void atmel_conf_pin_config_dbg_show(struct pinctrl_dev *pctldev,
+                                          struct seq_file *s, unsigned pin_id)
+{
+       struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
+       u32 conf;
+
+       if (!atmel_pioctrl->pins[pin_id]->device)
+               return;
+
+       if (atmel_pioctrl->pins[pin_id])
+               seq_printf(s, " (%s, ioset %u) ",
+                          atmel_pioctrl->pins[pin_id]->device,
+                          atmel_pioctrl->pins[pin_id]->ioset);
+
+       conf = atmel_pin_config_read(pctldev, pin_id);
+       if (conf & ATMEL_PIO_PUEN_MASK)
+               seq_printf(s, "%s ", "pull-up");
+       if (conf & ATMEL_PIO_PDEN_MASK)
+               seq_printf(s, "%s ", "pull-down");
+       if (conf & ATMEL_PIO_IFEN_MASK)
+               seq_printf(s, "%s ", "debounce");
+       if (conf & ATMEL_PIO_OPD_MASK)
+               seq_printf(s, "%s ", "open-drain");
+       if (conf & ATMEL_PIO_SCHMITT_MASK)
+               seq_printf(s, "%s ", "schmitt");
+}
+
+static const struct pinconf_ops atmel_confops = {
+       .pin_config_group_get   = atmel_conf_pin_config_group_get,
+       .pin_config_group_set   = atmel_conf_pin_config_group_set,
+       .pin_config_dbg_show    = atmel_conf_pin_config_dbg_show,
+};
+
+static struct pinctrl_desc atmel_pinctrl_desc = {
+       .name           = "atmel_pinctrl",
+       .confops        = &atmel_confops,
+       .pctlops        = &atmel_pctlops,
+       .pmxops         = &atmel_pmxops,
+};
+
+/*
+ * The number of banks can be different from a SoC to another one.
+ * We can have up to 16 banks.
+ */
+static const struct atmel_pioctrl_data atmel_sama5d2_pioctrl_data = {
+       .nbanks         = 4,
+};
+
+static const struct of_device_id atmel_pctrl_of_match[] = {
+       {
+               .compatible = "atmel,sama5d2-pinctrl",
+               .data = &atmel_sama5d2_pioctrl_data,
+       }, {
+               /* sentinel */
+       }
+};
+MODULE_DEVICE_TABLE(of, atmel_pctrl_of_match);
+
+static int atmel_pinctrl_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct pinctrl_pin_desc *pin_desc;
+       const char **group_names;
+       const struct of_device_id *match;
+       int i, ret;
+       struct resource *res;
+       struct atmel_pioctrl *atmel_pioctrl;
+       struct atmel_pioctrl_data *atmel_pioctrl_data;
+
+       atmel_pioctrl = devm_kzalloc(dev, sizeof(*atmel_pioctrl), GFP_KERNEL);
+       if (!atmel_pioctrl)
+               return -ENOMEM;
+       atmel_pioctrl->dev = dev;
+       atmel_pioctrl->node = dev->of_node;
+       platform_set_drvdata(pdev, atmel_pioctrl);
+
+       match = of_match_node(atmel_pctrl_of_match, dev->of_node);
+       if (!match) {
+               dev_err(dev, "unknown compatible string\n");
+               return -ENODEV;
+       }
+       atmel_pioctrl_data = (struct atmel_pioctrl_data *)match->data;
+       atmel_pioctrl->nbanks = atmel_pioctrl_data->nbanks;
+       atmel_pioctrl->npins = atmel_pioctrl->nbanks * ATMEL_PIO_NPINS_PER_BANK;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(dev, "unable to get atmel pinctrl resource\n");
+               return -EINVAL;
+       }
+       atmel_pioctrl->reg_base = devm_ioremap_resource(dev, res);
+       if (IS_ERR(atmel_pioctrl->reg_base))
+               return -EINVAL;
+
+       atmel_pioctrl->clk = devm_clk_get(dev, NULL);
+       if (IS_ERR(atmel_pioctrl->clk)) {
+               dev_err(dev, "failed to get clock\n");
+               return PTR_ERR(atmel_pioctrl->clk);
+       }
+
+       atmel_pioctrl->pins = devm_kzalloc(dev, sizeof(*atmel_pioctrl->pins)
+                       * atmel_pioctrl->npins, GFP_KERNEL);
+       if (!atmel_pioctrl->pins)
+               return -ENOMEM;
+
+       pin_desc = devm_kzalloc(dev, sizeof(*pin_desc)
+                       * atmel_pioctrl->npins, GFP_KERNEL);
+       if (!pin_desc)
+               return -ENOMEM;
+       atmel_pinctrl_desc.pins = pin_desc;
+       atmel_pinctrl_desc.npins = atmel_pioctrl->npins;
+
+       /* One pin is one group since a pin can achieve all functions. */
+       group_names = devm_kzalloc(dev, sizeof(*group_names)
+                       * atmel_pioctrl->npins, GFP_KERNEL);
+       if (!group_names)
+               return -ENOMEM;
+       atmel_pioctrl->group_names = group_names;
+
+       atmel_pioctrl->groups = devm_kzalloc(&pdev->dev,
+                       sizeof(*atmel_pioctrl->groups) * atmel_pioctrl->npins,
+                       GFP_KERNEL);
+       if (!atmel_pioctrl->groups)
+               return -ENOMEM;
+       for (i = 0 ; i < atmel_pioctrl->npins; i++) {
+               struct atmel_group *group = atmel_pioctrl->groups + i;
+               unsigned bank = ATMEL_PIO_BANK(i);
+               unsigned line = ATMEL_PIO_LINE(i);
+
+               atmel_pioctrl->pins[i] = devm_kzalloc(dev,
+                               sizeof(**atmel_pioctrl->pins), GFP_KERNEL);
+               if (!atmel_pioctrl->pins[i])
+                       return -ENOMEM;
+
+               atmel_pioctrl->pins[i]->pin_id = i;
+               atmel_pioctrl->pins[i]->bank = bank;
+               atmel_pioctrl->pins[i]->line = line;
+
+               pin_desc[i].number = i;
+               /* Pin naming convention: P(bank_name)(bank_pin_number). */
+               pin_desc[i].name = kasprintf(GFP_KERNEL, "P%c%d",
+                                            bank + 'A', line);
+
+               group->name = group_names[i] = pin_desc[i].name;
+               group->pin = pin_desc[i].number;
+
+               dev_dbg(dev, "pin_id=%u, bank=%u, line=%u", i, bank, line);
+       }
+
+       atmel_pioctrl->gpio_chip = &atmel_gpio_chip;
+       atmel_pioctrl->gpio_chip->of_node = dev->of_node;
+       atmel_pioctrl->gpio_chip->ngpio = atmel_pioctrl->npins;
+       atmel_pioctrl->gpio_chip->label = dev_name(dev);
+       atmel_pioctrl->gpio_chip->dev = dev;
+       atmel_pioctrl->gpio_chip->names = atmel_pioctrl->group_names;
+
+       atmel_pioctrl->irqs = devm_kzalloc(dev, sizeof(*atmel_pioctrl->irqs)
+                       * atmel_pioctrl->nbanks, GFP_KERNEL);
+       if (!atmel_pioctrl->irqs)
+               return -ENOMEM;
+
+       /* There is one controller but each bank has its own irq line. */
+       for (i = 0; i < atmel_pioctrl->nbanks; i++) {
+               res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
+               if (!res) {
+                       dev_err(dev, "missing irq resource for group %c\n",
+                               'A' + i);
+                       return -EINVAL;
+               }
+               atmel_pioctrl->irqs[i] = res->start;
+               irq_set_chained_handler(res->start, atmel_gpio_irq_handler);
+               irq_set_handler_data(res->start, atmel_pioctrl);
+               dev_dbg(dev, "bank %i: hwirq=%u\n", i, res->start);
+       }
+
+       atmel_pioctrl->irq_domain = irq_domain_add_linear(dev->of_node,
+                       atmel_pioctrl->gpio_chip->ngpio,
+                       &irq_domain_simple_ops, NULL);
+       if (!atmel_pioctrl->irq_domain) {
+               dev_err(dev, "can't add the irq domain\n");
+               return -ENODEV;
+       }
+       atmel_pioctrl->irq_domain->name = "atmel gpio";
+
+       for (i = 0; i < atmel_pioctrl->npins; i++) {
+               int irq = irq_create_mapping(atmel_pioctrl->irq_domain, i);
+
+               irq_set_chip_and_handler(irq, &atmel_gpio_irq_chip,
+                                        handle_simple_irq);
+               irq_set_chip_data(irq, atmel_pioctrl);
+               dev_dbg(dev,
+                       "atmel gpio irq domain: hwirq: %d, linux irq: %d\n",
+                       i, irq);
+       }
+
+       ret = clk_prepare_enable(atmel_pioctrl->clk);
+       if (ret) {
+               dev_err(dev, "failed to prepare and enable clock\n");
+               goto clk_prepare_enable_error;
+       }
+
+       atmel_pioctrl->pinctrl_dev = pinctrl_register(&atmel_pinctrl_desc,
+                                                     &pdev->dev,
+                                                     atmel_pioctrl);
+       if (!atmel_pioctrl->pinctrl_dev) {
+               dev_err(dev, "pinctrl registration failed\n");
+               goto pinctrl_register_error;
+       }
+
+       ret = gpiochip_add(atmel_pioctrl->gpio_chip);
+       if (ret) {
+               dev_err(dev, "failed to add gpiochip\n");
+               goto gpiochip_add_error;
+       }
+
+       ret = gpiochip_add_pin_range(atmel_pioctrl->gpio_chip, dev_name(dev),
+                                    0, 0, atmel_pioctrl->gpio_chip->ngpio);
+       if (ret) {
+               dev_err(dev, "failed to add gpio pin range\n");
+               goto gpiochip_add_pin_range_error;
+       }
+
+       dev_info(&pdev->dev, "atmel pinctrl initialized\n");
+
+       return 0;
+
+clk_prepare_enable_error:
+       irq_domain_remove(atmel_pioctrl->irq_domain);
+pinctrl_register_error:
+       clk_disable_unprepare(atmel_pioctrl->clk);
+gpiochip_add_error:
+       pinctrl_unregister(atmel_pioctrl->pinctrl_dev);
+gpiochip_add_pin_range_error:
+       gpiochip_remove(atmel_pioctrl->gpio_chip);
+
+       return ret;
+}
+
+int atmel_pinctrl_remove(struct platform_device *pdev)
+{
+       struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
+
+       irq_domain_remove(atmel_pioctrl->irq_domain);
+       clk_disable_unprepare(atmel_pioctrl->clk);
+       pinctrl_unregister(atmel_pioctrl->pinctrl_dev);
+       gpiochip_remove(atmel_pioctrl->gpio_chip);
+
+       return 0;
+}
+
+static struct platform_driver atmel_pinctrl_driver = {
+       .driver = {
+               .name = "pinctrl-at91-pio4",
+               .of_match_table = atmel_pctrl_of_match,
+       },
+       .probe = atmel_pinctrl_probe,
+       .remove = atmel_pinctrl_remove,
+};
+module_platform_driver(atmel_pinctrl_driver);
+
+MODULE_AUTHOR(Ludovic Desroches <ludovic.desroches@atmel.com>);
+MODULE_DESCRIPTION("Atmel PIO4 pinctrl driver");
+MODULE_LICENSE("GPL v2");