sh: pfc: Shuffle PFC support core.

This follows the intc/clk changes and shuffles the PFC support code under
its own directory. This will facilitate better code sharing, and allow us
to trim down the exported interface by quite a margin.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

4 files changed, 903 insertions, 0 deletions

diff --git a/drivers/sh/pfc/Kconfig b/drivers/sh/pfc/Kconfig
new file mode 100644
index 000000000000..95b04f4edb88
--- /dev/null
+++ b/drivers/sh/pfc/Kconfig
@@ -0,0 +1,14 @@
+comment "Pin function controller options"
+
+config SH_PFC
+        # XXX move off the gpio dependency
+        depends on GENERIC_GPIO
+        select GPIO_SH_PFC if ARCH_REQUIRE_GPIOLIB
+        def_bool y
+
+config GPIO_SH_PFC
+        tristate "SuperH PFC GPIO support"
+        depends on SH_PFC && GPIOLIB
+        help
+          This enables support for GPIOs within the SoC's pin function
+          controller.
diff --git a/drivers/sh/pfc/Makefile b/drivers/sh/pfc/Makefile
new file mode 100644
index 000000000000..d81707744b27
--- /dev/null
+++ b/drivers/sh/pfc/Makefile
@@ -0,0 +1,2 @@
+obj-y                           += core.o
+obj-$(CONFIG_GPIO_SH_PFC)       += gpio.o
diff --git a/drivers/sh/pfc/core.c b/drivers/sh/pfc/core.c
new file mode 100644
index 000000000000..ce4579ebd602
--- /dev/null
+++ b/drivers/sh/pfc/core.c
@@ -0,0 +1,578 @@
+/*
+ * SuperH Pin Function Controller support.
+ *
+ * Copyright (C) 2008 Magnus Damm
+ * Copyright (C) 2009 - 2012 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sh_pfc.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+
+static struct sh_pfc *sh_pfc __read_mostly;
+
+static inline bool sh_pfc_initialized(void)
+{
+        return !!sh_pfc;
+}
+
+static void pfc_iounmap(struct sh_pfc *pfc)
+{
+        int k;
+
+        for (k = 0; k < pfc->num_resources; k++)
+                if (pfc->window[k].virt)
+                        iounmap(pfc->window[k].virt);
+
+        kfree(pfc->window);
+        pfc->window = NULL;
+}
+
+static int pfc_ioremap(struct sh_pfc *pfc)
+{
+        struct resource *res;
+        int k;
+
+        if (!pfc->num_resources)
+                return 0;
+
+        pfc->window = kzalloc(pfc->num_resources * sizeof(*pfc->window),
+                              GFP_NOWAIT);
+        if (!pfc->window)
+                goto err1;
+
+        for (k = 0; k < pfc->num_resources; k++) {
+                res = pfc->resource + k;
+                WARN_ON(resource_type(res) != IORESOURCE_MEM);
+                pfc->window[k].phys = res->start;
+                pfc->window[k].size = resource_size(res);
+                pfc->window[k].virt = ioremap_nocache(res->start,
+                                                         resource_size(res));
+                if (!pfc->window[k].virt)
+                        goto err2;
+        }
+
+        return 0;
+
+err2:
+        pfc_iounmap(pfc);
+err1:
+        return -1;
+}
+
+static void __iomem *pfc_phys_to_virt(struct sh_pfc *pfc,
+                                      unsigned long address)
+{
+        struct pfc_window *window;
+        int k;
+
+        /* scan through physical windows and convert address */
+        for (k = 0; k < pfc->num_resources; k++) {
+                window = pfc->window + k;
+
+                if (address < window->phys)
+                        continue;
+
+                if (address >= (window->phys + window->size))
+                        continue;
+
+                return window->virt + (address - window->phys);
+        }
+
+        /* no windows defined, register must be 1:1 mapped virt:phys */
+        return (void __iomem *)address;
+}
+
+static int enum_in_range(pinmux_enum_t enum_id, struct pinmux_range *r)
+{
+        if (enum_id < r->begin)
+                return 0;
+
+        if (enum_id > r->end)
+                return 0;
+
+        return 1;
+}
+
+static unsigned long gpio_read_raw_reg(void __iomem *mapped_reg,
+                                       unsigned long reg_width)
+{
+        switch (reg_width) {
+        case 8:
+                return ioread8(mapped_reg);
+        case 16:
+                return ioread16(mapped_reg);
+        case 32:
+                return ioread32(mapped_reg);
+        }
+
+        BUG();
+        return 0;
+}
+
+static void gpio_write_raw_reg(void __iomem *mapped_reg,
+                               unsigned long reg_width,
+                               unsigned long data)
+{
+        switch (reg_width) {
+        case 8:
+                iowrite8(data, mapped_reg);
+                return;
+        case 16:
+                iowrite16(data, mapped_reg);
+                return;
+        case 32:
+                iowrite32(data, mapped_reg);
+                return;
+        }
+
+        BUG();
+}
+
+int sh_pfc_read_bit(struct pinmux_data_reg *dr, unsigned long in_pos)
+{
+        unsigned long pos;
+
+        pos = dr->reg_width - (in_pos + 1);
+
+        pr_debug("read_bit: addr = %lx, pos = %ld, "
+                 "r_width = %ld\n", dr->reg, pos, dr->reg_width);
+
+        return (gpio_read_raw_reg(dr->mapped_reg, dr->reg_width) >> pos) & 1;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_read_bit);
+
+void sh_pfc_write_bit(struct pinmux_data_reg *dr, unsigned long in_pos,
+                      unsigned long value)
+{
+        unsigned long pos;
+
+        pos = dr->reg_width - (in_pos + 1);
+
+        pr_debug("write_bit addr = %lx, value = %d, pos = %ld, "
+                 "r_width = %ld\n",
+                 dr->reg, !!value, pos, dr->reg_width);
+
+        if (value)
+                set_bit(pos, &dr->reg_shadow);
+        else
+                clear_bit(pos, &dr->reg_shadow);
+
+        gpio_write_raw_reg(dr->mapped_reg, dr->reg_width, dr->reg_shadow);
+}
+EXPORT_SYMBOL_GPL(sh_pfc_write_bit);
+
+static void config_reg_helper(struct sh_pfc *pfc,
+                              struct pinmux_cfg_reg *crp,
+                              unsigned long in_pos,
+                              void __iomem **mapped_regp,
+                              unsigned long *maskp,
+                              unsigned long *posp)
+{
+        int k;
+
+        *mapped_regp = pfc_phys_to_virt(pfc, crp->reg);
+
+        if (crp->field_width) {
+                *maskp = (1 << crp->field_width) - 1;
+                *posp = crp->reg_width - ((in_pos + 1) * crp->field_width);
+        } else {
+                *maskp = (1 << crp->var_field_width[in_pos]) - 1;
+                *posp = crp->reg_width;
+                for (k = 0; k <= in_pos; k++)
+                        *posp -= crp->var_field_width[k];
+        }
+}
+
+static int read_config_reg(struct sh_pfc *pfc,
+                           struct pinmux_cfg_reg *crp,
+                           unsigned long field)
+{
+        void __iomem *mapped_reg;
+        unsigned long mask, pos;
+
+        config_reg_helper(pfc, crp, field, &mapped_reg, &mask, &pos);
+
+        pr_debug("read_reg: addr = %lx, field = %ld, "
+                 "r_width = %ld, f_width = %ld\n",
+                 crp->reg, field, crp->reg_width, crp->field_width);
+
+        return (gpio_read_raw_reg(mapped_reg, crp->reg_width) >> pos) & mask;
+}
+
+static void write_config_reg(struct sh_pfc *pfc,
+                             struct pinmux_cfg_reg *crp,
+                             unsigned long field, unsigned long value)
+{
+        void __iomem *mapped_reg;
+        unsigned long mask, pos, data;
+
+        config_reg_helper(pfc, crp, field, &mapped_reg, &mask, &pos);
+
+        pr_debug("write_reg addr = %lx, value = %ld, field = %ld, "
+                 "r_width = %ld, f_width = %ld\n",
+                 crp->reg, value, field, crp->reg_width, crp->field_width);
+
+        mask = ~(mask << pos);
+        value = value << pos;
+
+        data = gpio_read_raw_reg(mapped_reg, crp->reg_width);
+        data &= mask;
+        data |= value;
+
+        if (pfc->unlock_reg)
+                gpio_write_raw_reg(pfc_phys_to_virt(pfc, pfc->unlock_reg),
+                                   32, ~data);
+
+        gpio_write_raw_reg(mapped_reg, crp->reg_width, data);
+}
+
+static int setup_data_reg(struct sh_pfc *pfc, unsigned gpio)
+{
+        struct pinmux_gpio *gpiop = &pfc->gpios[gpio];
+        struct pinmux_data_reg *data_reg;
+        int k, n;
+
+        if (!enum_in_range(gpiop->enum_id, &pfc->data))
+                return -1;
+
+        k = 0;
+        while (1) {
+                data_reg = pfc->data_regs + k;
+
+                if (!data_reg->reg_width)
+                        break;
+
+                data_reg->mapped_reg = pfc_phys_to_virt(pfc, data_reg->reg);
+
+                for (n = 0; n < data_reg->reg_width; n++) {
+                        if (data_reg->enum_ids[n] == gpiop->enum_id) {
+                                gpiop->flags &= ~PINMUX_FLAG_DREG;
+                                gpiop->flags |= (k << PINMUX_FLAG_DREG_SHIFT);
+                                gpiop->flags &= ~PINMUX_FLAG_DBIT;
+                                gpiop->flags |= (n << PINMUX_FLAG_DBIT_SHIFT);
+                                return 0;
+                        }
+                }
+                k++;
+        }
+
+        BUG();
+
+        return -1;
+}
+
+static void setup_data_regs(struct sh_pfc *pfc)
+{
+        struct pinmux_data_reg *drp;
+        int k;
+
+        for (k = pfc->first_gpio; k <= pfc->last_gpio; k++)
+                setup_data_reg(pfc, k);
+
+        k = 0;
+        while (1) {
+                drp = pfc->data_regs + k;
+
+                if (!drp->reg_width)
+                        break;
+
+                drp->reg_shadow = gpio_read_raw_reg(drp->mapped_reg,
+                                                    drp->reg_width);
+                k++;
+        }
+}
+
+int sh_pfc_get_data_reg(struct sh_pfc *pfc, unsigned gpio,
+                        struct pinmux_data_reg **drp, int *bitp)
+{
+        struct pinmux_gpio *gpiop = &pfc->gpios[gpio];
+        int k, n;
+
+        if (!enum_in_range(gpiop->enum_id, &pfc->data))
+                return -1;
+
+        k = (gpiop->flags & PINMUX_FLAG_DREG) >> PINMUX_FLAG_DREG_SHIFT;
+        n = (gpiop->flags & PINMUX_FLAG_DBIT) >> PINMUX_FLAG_DBIT_SHIFT;
+        *drp = pfc->data_regs + k;
+        *bitp = n;
+        return 0;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_get_data_reg);
+
+static int get_config_reg(struct sh_pfc *pfc, pinmux_enum_t enum_id,
+                          struct pinmux_cfg_reg **crp,
+                          int *fieldp, int *valuep,
+                          unsigned long **cntp)
+{
+        struct pinmux_cfg_reg *config_reg;
+        unsigned long r_width, f_width, curr_width, ncomb;
+        int k, m, n, pos, bit_pos;
+
+        k = 0;
+        while (1) {
+                config_reg = pfc->cfg_regs + k;
+
+                r_width = config_reg->reg_width;
+                f_width = config_reg->field_width;
+
+                if (!r_width)
+                        break;
+
+                pos = 0;
+                m = 0;
+                for (bit_pos = 0; bit_pos < r_width; bit_pos += curr_width) {
+                        if (f_width)
+                                curr_width = f_width;
+                        else
+                                curr_width = config_reg->var_field_width[m];
+
+                        ncomb = 1 << curr_width;
+                        for (n = 0; n < ncomb; n++) {
+                                if (config_reg->enum_ids[pos + n] == enum_id) {
+                                        *crp = config_reg;
+                                        *fieldp = m;
+                                        *valuep = n;
+                                        *cntp = &config_reg->cnt[m];
+                                        return 0;
+                                }
+                        }
+                        pos += ncomb;
+                        m++;
+                }
+                k++;
+        }
+
+        return -1;
+}
+
+int sh_pfc_gpio_to_enum(struct sh_pfc *pfc, unsigned gpio, int pos,
+                        pinmux_enum_t *enum_idp)
+{
+        pinmux_enum_t enum_id = pfc->gpios[gpio].enum_id;
+        pinmux_enum_t *data = pfc->gpio_data;
+        int k;
+
+        if (!enum_in_range(enum_id, &pfc->data)) {
+                if (!enum_in_range(enum_id, &pfc->mark)) {
+                        pr_err("non data/mark enum_id for gpio %d\n", gpio);
+                        return -1;
+                }
+        }
+
+        if (pos) {
+                *enum_idp = data[pos + 1];
+                return pos + 1;
+        }
+
+        for (k = 0; k < pfc->gpio_data_size; k++) {
+                if (data[k] == enum_id) {
+                        *enum_idp = data[k + 1];
+                        return k + 1;
+                }
+        }
+
+        pr_err("cannot locate data/mark enum_id for gpio %d\n", gpio);
+        return -1;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_gpio_to_enum);
+
+int sh_pfc_config_gpio(struct sh_pfc *pfc, unsigned gpio, int pinmux_type,
+                       int cfg_mode)
+{
+        struct pinmux_cfg_reg *cr = NULL;
+        pinmux_enum_t enum_id;
+        struct pinmux_range *range;
+        int in_range, pos, field, value;
+        unsigned long *cntp;
+
+        switch (pinmux_type) {
+
+        case PINMUX_TYPE_FUNCTION:
+                range = NULL;
+                break;
+
+        case PINMUX_TYPE_OUTPUT:
+                range = &pfc->output;
+                break;
+
+        case PINMUX_TYPE_INPUT:
+                range = &pfc->input;
+                break;
+
+        case PINMUX_TYPE_INPUT_PULLUP:
+                range = &pfc->input_pu;
+                break;
+
+        case PINMUX_TYPE_INPUT_PULLDOWN:
+                range = &pfc->input_pd;
+                break;
+
+        default:
+                goto out_err;
+        }
+
+        pos = 0;
+        enum_id = 0;
+        field = 0;
+        value = 0;
+        while (1) {
+                pos = sh_pfc_gpio_to_enum(pfc, gpio, pos, &enum_id);
+                if (pos <= 0)
+                        goto out_err;
+
+                if (!enum_id)
+                        break;
+
+                /* first check if this is a function enum */
+                in_range = enum_in_range(enum_id, &pfc->function);
+                if (!in_range) {
+                        /* not a function enum */
+                        if (range) {
+                                /*
+                                 * other range exists, so this pin is
+                                 * a regular GPIO pin that now is being
+                                 * bound to a specific direction.
+                                 *
+                                 * for this case we only allow function enums
+                                 * and the enums that match the other range.
+                                 */
+                                in_range = enum_in_range(enum_id, range);
+
+                                /*
+                                 * special case pass through for fixed
+                                 * input-only or output-only pins without
+                                 * function enum register association.
+                                 */
+                                if (in_range && enum_id == range->force)
+                                        continue;
+                        } else {
+                                /*
+                                 * no other range exists, so this pin
+                                 * must then be of the function type.
+                                 *
+                                 * allow function type pins to select
+                                 * any combination of function/in/out
+                                 * in their MARK lists.
+                                 */
+                                in_range = 1;
+                        }
+                }
+
+                if (!in_range)
+                        continue;
+
+                if (get_config_reg(pfc, enum_id, &cr,
+                                   &field, &value, &cntp) != 0)
+                        goto out_err;
+
+                switch (cfg_mode) {
+                case GPIO_CFG_DRYRUN:
+                        if (!*cntp ||
+                            (read_config_reg(pfc, cr, field) != value))
+                                continue;
+                        break;
+
+                case GPIO_CFG_REQ:
+                        write_config_reg(pfc, cr, field, value);
+                        *cntp = *cntp + 1;
+                        break;
+
+                case GPIO_CFG_FREE:
+                        *cntp = *cntp - 1;
+                        break;
+                }
+        }
+
+        return 0;
+ out_err:
+        return -1;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_config_gpio);
+
+int sh_pfc_set_direction(struct sh_pfc *pfc, unsigned gpio,
+                         int new_pinmux_type)
+{
+        int pinmux_type;
+        int ret = -EINVAL;
+
+        if (!pfc)
+                goto err_out;
+
+        pinmux_type = pfc->gpios[gpio].flags & PINMUX_FLAG_TYPE;
+
+        switch (pinmux_type) {
+        case PINMUX_TYPE_GPIO:
+                break;
+        case PINMUX_TYPE_OUTPUT:
+        case PINMUX_TYPE_INPUT:
+        case PINMUX_TYPE_INPUT_PULLUP:
+        case PINMUX_TYPE_INPUT_PULLDOWN:
+                sh_pfc_config_gpio(pfc, gpio, pinmux_type, GPIO_CFG_FREE);
+                break;
+        default:
+                goto err_out;
+        }
+
+        if (sh_pfc_config_gpio(pfc, gpio,
+                               new_pinmux_type,
+                               GPIO_CFG_DRYRUN) != 0)
+                goto err_out;
+
+        if (sh_pfc_config_gpio(pfc, gpio,
+                               new_pinmux_type,
+                               GPIO_CFG_REQ) != 0)
+                BUG();
+
+        pfc->gpios[gpio].flags &= ~PINMUX_FLAG_TYPE;
+        pfc->gpios[gpio].flags |= new_pinmux_type;
+
+        ret = 0;
+ err_out:
+        return ret;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_set_direction);
+
+int register_sh_pfc(struct sh_pfc *pfc)
+{
+        int (*initroutine)(struct sh_pfc *) = NULL;
+        int ret;
+
+        /*
+         * Ensure that the type encoding fits
+         */
+        BUILD_BUG_ON(PINMUX_FLAG_TYPE > ((1 << PINMUX_FLAG_DBIT_SHIFT) - 1));
+
+        if (sh_pfc)
+                return -EBUSY;
+
+        ret = pfc_ioremap(pfc);
+        if (unlikely(ret < 0))
+                return ret;
+
+        spin_lock_init(&pfc->lock);
+
+        setup_data_regs(pfc);
+
+        sh_pfc = pfc;
+        pr_info("%s support registered\n", pfc->name);
+
+        initroutine = symbol_request(sh_pfc_register_gpiochip);
+        if (initroutine) {
+                (*initroutine)(pfc);
+                symbol_put_addr(initroutine);
+        }
+
+        return 0;
+}
diff --git a/drivers/sh/pfc/gpio.c b/drivers/sh/pfc/gpio.c
new file mode 100644
index 000000000000..d74e5a96024b
--- /dev/null
+++ b/drivers/sh/pfc/gpio.c
@@ -0,0 +1,309 @@
+/*
+ * SuperH Pin Function Controller GPIO driver.
+ *
+ * Copyright (C) 2008 Magnus Damm
+ * Copyright (C) 2009 - 2012 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct sh_pfc_chip {
+        struct sh_pfc           *pfc;
+        struct gpio_chip        gpio_chip;
+};
+
+static struct sh_pfc_chip *gpio_to_pfc_chip(struct gpio_chip *gc)
+{
+        return container_of(gc, struct sh_pfc_chip, gpio_chip);
+}
+
+static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
+{
+        return gpio_to_pfc_chip(gc)->pfc;
+}
+
+static int sh_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+        struct sh_pfc *pfc = gpio_to_pfc(gc);
+        struct pinmux_data_reg *dummy;
+        unsigned long flags;
+        int i, ret, pinmux_type;
+
+        ret = -EINVAL;
+
+        if (!pfc)
+                goto err_out;
+
+        spin_lock_irqsave(&pfc->lock, flags);
+
+        if ((pfc->gpios[offset].flags & PINMUX_FLAG_TYPE) != PINMUX_TYPE_NONE)
+                goto err_unlock;
+
+        /* setup pin function here if no data is associated with pin */
+
+        if (sh_pfc_get_data_reg(pfc, offset, &dummy, &i) != 0)
+                pinmux_type = PINMUX_TYPE_FUNCTION;
+        else
+                pinmux_type = PINMUX_TYPE_GPIO;
+
+        if (pinmux_type == PINMUX_TYPE_FUNCTION) {
+                if (sh_pfc_config_gpio(pfc, offset,
+                                       pinmux_type,
+                                       GPIO_CFG_DRYRUN) != 0)
+                        goto err_unlock;
+
+                if (sh_pfc_config_gpio(pfc, offset,
+                                       pinmux_type,
+                                       GPIO_CFG_REQ) != 0)
+                        BUG();
+        }
+
+        pfc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
+        pfc->gpios[offset].flags |= pinmux_type;
+
+        ret = 0;
+ err_unlock:
+        spin_unlock_irqrestore(&pfc->lock, flags);
+ err_out:
+        return ret;
+}
+
+static void sh_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+        struct sh_pfc *pfc = gpio_to_pfc(gc);
+        unsigned long flags;
+        int pinmux_type;
+
+        if (!pfc)
+                return;
+
+        spin_lock_irqsave(&pfc->lock, flags);
+
+        pinmux_type = pfc->gpios[offset].flags & PINMUX_FLAG_TYPE;
+        sh_pfc_config_gpio(pfc, offset, pinmux_type, GPIO_CFG_FREE);
+        pfc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
+        pfc->gpios[offset].flags |= PINMUX_TYPE_NONE;
+
+        spin_unlock_irqrestore(&pfc->lock, flags);
+}
+
+static int sh_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+        struct sh_pfc *pfc = gpio_to_pfc(gc);
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&pfc->lock, flags);
+        ret = sh_pfc_set_direction(pfc, offset, PINMUX_TYPE_INPUT);
+        spin_unlock_irqrestore(&pfc->lock, flags);
+
+        return ret;
+}
+
+static void sh_gpio_set_value(struct sh_pfc *pfc, unsigned gpio, int value)
+{
+        struct pinmux_data_reg *dr = NULL;
+        int bit = 0;
+
+        if (!pfc || sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
+                BUG();
+        else
+                sh_pfc_write_bit(dr, bit, value);
+}
+
+static int sh_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
+                                    int value)
+{
+        struct sh_pfc *pfc = gpio_to_pfc(gc);
+        unsigned long flags;
+        int ret;
+
+        sh_gpio_set_value(pfc, offset, value);
+
+        spin_lock_irqsave(&pfc->lock, flags);
+        ret = sh_pfc_set_direction(pfc, offset, PINMUX_TYPE_OUTPUT);
+        spin_unlock_irqrestore(&pfc->lock, flags);
+
+        return ret;
+}
+
+static int sh_gpio_get_value(struct sh_pfc *pfc, unsigned gpio)
+{
+        struct pinmux_data_reg *dr = NULL;
+        int bit = 0;
+
+        if (!pfc || sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
+                return -EINVAL;
+
+        return sh_pfc_read_bit(dr, bit);
+}
+
+static int sh_gpio_get(struct gpio_chip *gc, unsigned offset)
+{
+        return sh_gpio_get_value(gpio_to_pfc(gc), offset);
+}
+
+static void sh_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+        sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
+}
+
+static int sh_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+        struct sh_pfc *pfc = gpio_to_pfc(gc);
+        pinmux_enum_t enum_id;
+        pinmux_enum_t *enum_ids;
+        int i, k, pos;
+
+        pos = 0;
+        enum_id = 0;
+        while (1) {
+                pos = sh_pfc_gpio_to_enum(pfc, offset, pos, &enum_id);
+                if (pos <= 0 || !enum_id)
+                        break;
+
+                for (i = 0; i < pfc->gpio_irq_size; i++) {
+                        enum_ids = pfc->gpio_irq[i].enum_ids;
+                        for (k = 0; enum_ids[k]; k++) {
+                                if (enum_ids[k] == enum_id)
+                                        return pfc->gpio_irq[i].irq;
+                        }
+                }
+        }
+
+        return -ENOSYS;
+}
+
+static void sh_pfc_gpio_setup(struct sh_pfc_chip *chip)
+{
+        struct sh_pfc *pfc = chip->pfc;
+        struct gpio_chip *gc = &chip->gpio_chip;
+
+        gc->request = sh_gpio_request;
+        gc->free = sh_gpio_free;
+        gc->direction_input = sh_gpio_direction_input;
+        gc->get = sh_gpio_get;
+        gc->direction_output = sh_gpio_direction_output;
+        gc->set = sh_gpio_set;
+        gc->to_irq = sh_gpio_to_irq;
+
+        WARN_ON(pfc->first_gpio != 0); /* needs testing */
+
+        gc->label = pfc->name;
+        gc->owner = THIS_MODULE;
+        gc->base = pfc->first_gpio;
+        gc->ngpio = (pfc->last_gpio - pfc->first_gpio) + 1;
+}
+
+int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
+{
+        struct sh_pfc_chip *chip;
+        int ret;
+
+        chip = kzalloc(sizeof(struct sh_pfc_chip), GFP_KERNEL);
+        if (unlikely(!chip))
+                return -ENOMEM;
+
+        chip->pfc = pfc;
+
+        sh_pfc_gpio_setup(chip);
+
+        ret = gpiochip_add(&chip->gpio_chip);
+        if (unlikely(ret < 0))
+                kfree(chip);
+
+        pr_info("%s handling gpio %d -> %d\n",
+                pfc->name, pfc->first_gpio, pfc->last_gpio);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(sh_pfc_register_gpiochip);
+
+static int sh_pfc_gpio_match(struct gpio_chip *gc, void *data)
+{
+        return !!strstr(gc->label, data);
+}
+
+static int __devinit sh_pfc_gpio_probe(struct platform_device *pdev)
+{
+        struct sh_pfc_chip *chip;
+        struct gpio_chip *gc;
+
+        gc = gpiochip_find("_pfc", sh_pfc_gpio_match);
+        if (unlikely(!gc)) {
+                pr_err("Cant find gpio chip\n");
+                return -ENODEV;
+        }
+
+        chip = gpio_to_pfc_chip(gc);
+        platform_set_drvdata(pdev, chip);
+
+        pr_info("attaching to GPIO chip %s\n", chip->pfc->name);
+
+        return 0;
+}
+
+static int __devexit sh_pfc_gpio_remove(struct platform_device *pdev)
+{
+        struct sh_pfc_chip *chip = platform_get_drvdata(pdev);
+        int ret;
+
+        ret = gpiochip_remove(&chip->gpio_chip);
+        if (unlikely(ret < 0))
+                return ret;
+
+        kfree(chip);
+        return 0;
+}
+
+static struct platform_driver sh_pfc_gpio_driver = {
+        .probe          = sh_pfc_gpio_probe,
+        .remove         = __devexit_p(sh_pfc_gpio_remove),
+        .driver         = {
+                .name   = KBUILD_MODNAME,
+                .owner  = THIS_MODULE,
+        },
+};
+
+static struct platform_device sh_pfc_gpio_device = {
+        .name           = KBUILD_MODNAME,
+        .id             = -1,
+};
+
+static int __init sh_pfc_gpio_init(void)
+{
+        int rc;
+
+        rc = platform_driver_register(&sh_pfc_gpio_driver);
+        if (likely(!rc)) {
+                rc = platform_device_register(&sh_pfc_gpio_device);
+                if (unlikely(rc))
+                        platform_driver_unregister(&sh_pfc_gpio_driver);
+        }
+
+        return rc;
+}
+
+static void __exit sh_pfc_gpio_exit(void)
+{
+        platform_device_unregister(&sh_pfc_gpio_device);
+        platform_driver_unregister(&sh_pfc_gpio_driver);
+}
+
+module_init(sh_pfc_gpio_init);
+module_exit(sh_pfc_gpio_exit);
+
+MODULE_AUTHOR("Magnus Damm, Paul Mundt");
+MODULE_DESCRIPTION("GPIO driver for SuperH pin function controller");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:pfc-gpio");