The Synopsys DesignWare APB GPIO driver only supports open firmware devices.
But, like Intel Quark X1000 SOC, which has a single PCI function exporting
a GPIO and an I2C controller, it is a Multifunction device. This patch is
to enable the current Synopsys DesignWare APB GPIO driver to support the
Multifunction device which exports the designware GPIO controller.

Reviewed-by: Hock Leong Kweh <hock.leong.k...@intel.com>
Reviewed-by: Shevchenko, Andriy <andriy.shevche...@intel.com>
Signed-off-by: Weike Chen <alvin.c...@intel.com>
---
 drivers/gpio/Kconfig                     |    1 -
 drivers/gpio/gpio-dwapb.c                |  187 ++++++++++++++++++++++--------
 include/linux/platform_data/gpio-dwapb.h |   32 +++++
 3 files changed, 171 insertions(+), 49 deletions(-)
 create mode 100644 include/linux/platform_data/gpio-dwapb.h

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 9de1515..8250a44 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -136,7 +136,6 @@ config GPIO_DWAPB
        tristate "Synopsys DesignWare APB GPIO driver"
        select GPIO_GENERIC
        select GENERIC_IRQ_CHIP
-       depends on OF_GPIO
        help
          Say Y or M here to build support for the Synopsys DesignWare APB
          GPIO block.
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index d6618a6..155a64b 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -21,6 +21,7 @@
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
+#include <linux/platform_data/gpio-dwapb.h>
 
 #define GPIO_SWPORTA_DR                0x00
 #define GPIO_SWPORTA_DDR       0x04
@@ -52,14 +53,15 @@ struct dwapb_gpio_port {
        struct bgpio_chip       bgc;
        bool                    is_registered;
        struct dwapb_gpio       *gpio;
+       struct dwapb_gpio_port_property *pp;
 };
 
 struct dwapb_gpio {
        struct  device          *dev;
        void __iomem            *regs;
        struct dwapb_gpio_port  *ports;
-       unsigned int            nr_ports;
        struct irq_domain       *domain;
+       const struct dwapb_gpio_platform_data   *pdata;
 };
 
 static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
@@ -207,22 +209,24 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 
type)
        return 0;
 }
 
+static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
+{
+       struct irq_desc *desc = irq_to_desc(irq);
+
+       dwapb_irq_handler(irq, desc);
+
+       return IRQ_HANDLED;
+}
+
 static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
                                 struct dwapb_gpio_port *port)
 {
        struct gpio_chip *gc = &port->bgc.gc;
-       struct device_node *node =  gc->of_node;
-       struct irq_chip_generic *irq_gc;
+       struct device_node *node = port->pp->node;
+       struct irq_chip_generic *irq_gc = NULL;
        unsigned int hwirq, ngpio = gc->ngpio;
        struct irq_chip_type *ct;
-       int err, irq, i;
-
-       irq = irq_of_parse_and_map(node, 0);
-       if (!irq) {
-               dev_warn(gpio->dev, "no irq for bank %s\n",
-                       port->bgc.gc.of_node->full_name);
-               return;
-       }
+       int err, i;
 
        gpio->domain = irq_domain_add_linear(node, ngpio,
                                             &irq_generic_chip_ops, gpio);
@@ -269,8 +273,24 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
        irq_gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
        irq_gc->chip_types[1].handler = handle_edge_irq;
 
-       irq_set_chained_handler(irq, dwapb_irq_handler);
-       irq_set_handler_data(irq, gpio);
+       if (!port->pp->irq_shared) {
+               irq_set_chained_handler(port->pp->irq, dwapb_irq_handler);
+       } else {
+               /*
+                * Request a shared IRQ since where MFD would have devices
+                * using the same irq pin
+                */
+               err = devm_request_irq(gpio->dev, port->pp->irq,
+                                      dwapb_irq_handler_mfd,
+                                      IRQF_SHARED, "gpio-dwapb-mfd", gpio);
+               if (err) {
+                       dev_err(gpio->dev, "error requesting IRQ\n");
+                       irq_domain_remove(gpio->domain);
+                       gpio->domain = NULL;
+                       return;
+               }
+       }
+       irq_set_handler_data(port->pp->irq, gpio);
 
        for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
                irq_create_mapping(gpio->domain, hwirq);
@@ -296,57 +316,43 @@ static void dwapb_irq_teardown(struct dwapb_gpio *gpio)
 }
 
 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
-                              struct device_node *port_np,
+                              struct dwapb_gpio_port_property *pp,
                               unsigned int offs)
 {
        struct dwapb_gpio_port *port;
-       u32 port_idx, ngpio;
        void __iomem *dat, *set, *dirout;
        int err;
 
-       if (of_property_read_u32(port_np, "reg", &port_idx) ||
-               port_idx >= DWAPB_MAX_PORTS) {
-               dev_err(gpio->dev, "missing/invalid port index for %s\n",
-                       port_np->full_name);
-               return -EINVAL;
-       }
-
        port = &gpio->ports[offs];
        port->gpio = gpio;
+       port->pp   = pp;
 
-       if (of_property_read_u32(port_np, "snps,nr-gpios", &ngpio)) {
-               dev_info(gpio->dev, "failed to get number of gpios for %s\n",
-                        port_np->full_name);
-               ngpio = 32;
-       }
-
-       dat = gpio->regs + GPIO_EXT_PORTA + (port_idx * GPIO_EXT_PORT_SIZE);
-       set = gpio->regs + GPIO_SWPORTA_DR + (port_idx * GPIO_SWPORT_DR_SIZE);
+       dat = gpio->regs + GPIO_EXT_PORTA + (pp->idx * GPIO_EXT_PORT_SIZE);
+       set = gpio->regs + GPIO_SWPORTA_DR + (pp->idx * GPIO_SWPORT_DR_SIZE);
        dirout = gpio->regs + GPIO_SWPORTA_DDR +
-               (port_idx * GPIO_SWPORT_DDR_SIZE);
+               (pp->idx * GPIO_SWPORT_DDR_SIZE);
 
        err = bgpio_init(&port->bgc, gpio->dev, 4, dat, set, NULL, dirout,
                         NULL, false);
        if (err) {
                dev_err(gpio->dev, "failed to init gpio chip for %s\n",
-                       port_np->full_name);
+                       pp->name);
                return err;
        }
 
-       port->bgc.gc.ngpio = ngpio;
-       port->bgc.gc.of_node = port_np;
+       port->bgc.gc.ngpio = pp->ngpio;
+       port->bgc.gc.base = pp->gpio_base;
 
        /*
         * Only port A can provide interrupts in all configurations of the IP.
         */
-       if (port_idx == 0 &&
-           of_property_read_bool(port_np, "interrupt-controller"))
+       if (pp->irq)
                dwapb_configure_irqs(gpio, port);
 
        err = gpiochip_add(&port->bgc.gc);
        if (err)
                dev_err(gpio->dev, "failed to register gpiochip for %s\n",
-                       port_np->full_name);
+                       pp->name);
        else
                port->is_registered = true;
 
@@ -357,30 +363,115 @@ static void dwapb_gpio_unregister(struct dwapb_gpio 
*gpio)
 {
        unsigned int m;
 
-       for (m = 0; m < gpio->nr_ports; ++m)
+       for (m = 0; m < gpio->pdata->nports; ++m)
                if (gpio->ports[m].is_registered)
                        gpiochip_remove(&gpio->ports[m].bgc.gc);
 }
 
+/*
+ * Handlers for alternative sources of platform_data
+ */
+
+#ifdef CONFIG_OF_GPIO
+/*
+ * Translate OpenFirmware node properties into platform_data
+ */
+static struct dwapb_gpio_platform_data *
+dwapb_gpio_get_pdata_of(struct device *dev)
+{
+       struct device_node *node, *port_np;
+       struct dwapb_gpio_platform_data *pdata;
+       struct dwapb_gpio_port_property *pp;
+       int nports;
+       int i;
+
+       node = dev->of_node;
+       if (!node)
+               return ERR_PTR(-ENODEV);
+
+       nports = of_get_child_count(node);
+       if (nports == 0)
+               return ERR_PTR(-ENODEV);
+
+       pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+       if (!pdata)
+               return ERR_PTR(-ENOMEM);
+
+       pdata->properties = devm_kcalloc(dev, nports, sizeof(*pp), GFP_KERNEL);
+       if (!pdata->properties)
+               return ERR_PTR(-ENOMEM);
+
+       pdata->nports = nports;
+
+       i = 0;
+       for_each_child_of_node(node, port_np) {
+               pp = &pdata->properties[i++];
+               pp->node = port_np;
+
+               if (of_property_read_u32(port_np, "reg", &pp->idx) ||
+                   pp->idx >= DWAPB_MAX_PORTS) {
+                       dev_err(dev, "missing/invalid port index for %s\n",
+                               port_np->full_name);
+                       return ERR_PTR(-EINVAL);
+               }
+
+               if (of_property_read_u32(port_np, "snps,nr-gpios",
+                                        &pp->ngpio)) {
+                       dev_info(dev, "failed to get number of gpios for %s\n",
+                                port_np->full_name);
+                       pp->ngpio = 32;
+               }
+
+               if (pp->idx == 0 &&
+                   of_property_read_bool(port_np, "interrupt-controller")) {
+                       pp->irq = irq_of_parse_and_map(port_np, 0);
+                       if (!pp->irq) {
+                               dev_warn(dev, "no irq for bank %s\n",
+                                        port_np->full_name);
+                       }
+               } else {
+                       pp->irq = 0;
+               }
+
+               pp->irq_shared  = false;
+               pp->gpio_base   = 0;
+               pp->name        = port_np->full_name;
+       }
+
+       return pdata;
+}
+#else
+static inline struct dwapb_gpio_platform_data *
+dwapb_gpio_get_pdata_of(struct device *dev)
+{
+       return ERR_PTR(-ENODEV);
+}
+#endif
+
 static int dwapb_gpio_probe(struct platform_device *pdev)
 {
+       int i;
        struct resource *res;
        struct dwapb_gpio *gpio;
-       struct device_node *np;
        int err;
-       unsigned int offs = 0;
+       struct device *dev = &pdev->dev;
+       const struct dwapb_gpio_platform_data *pdata = dev_get_platdata(dev);
+
+       if (!pdata) {
+               pdata = dwapb_gpio_get_pdata_of(dev);
+               if (IS_ERR(pdata))
+                       return PTR_ERR(pdata);
+       }
+       if (!pdata->nports)
+               return -ENODEV;
 
        gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
        if (!gpio)
                return -ENOMEM;
        gpio->dev = &pdev->dev;
+       gpio->pdata = pdata;
 
-       gpio->nr_ports = of_get_child_count(pdev->dev.of_node);
-       if (!gpio->nr_ports) {
-               err = -EINVAL;
-               goto out_err;
-       }
-       gpio->ports = devm_kzalloc(&pdev->dev, gpio->nr_ports *
+       gpio->ports = devm_kcalloc(&pdev->dev, pdata->nports,
                                   sizeof(*gpio->ports), GFP_KERNEL);
        if (!gpio->ports) {
                err = -ENOMEM;
@@ -394,8 +485,8 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
                goto out_err;
        }
 
-       for_each_child_of_node(pdev->dev.of_node, np) {
-               err = dwapb_gpio_add_port(gpio, np, offs++);
+       for (i = 0; i < pdata->nports; i++) {
+               err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
                if (err)
                        goto out_unregister;
        }
diff --git a/include/linux/platform_data/gpio-dwapb.h 
b/include/linux/platform_data/gpio-dwapb.h
new file mode 100644
index 0000000..1f1ce3a
--- /dev/null
+++ b/include/linux/platform_data/gpio-dwapb.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright(c) 2014 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ */
+
+#ifndef GPIO_DW_APB_H
+#define GPIO_DW_APB_H
+
+struct dwapb_gpio_port_property {
+       struct device_node *node;
+       const char      *name;
+       unsigned int    idx;
+       unsigned int    ngpio;
+       unsigned int    gpio_base;
+       unsigned int    irq;
+       bool            irq_shared;
+};
+
+struct dwapb_gpio_platform_data {
+       struct dwapb_gpio_port_property *properties;
+       unsigned int nports;
+};
+
+#endif
-- 
1.7.9.5

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