[PATCH 1/4 v5] GPIO: gpio-dwapb: Enable platform driver binding to MFD driver

From: Weike Chen
Date: Wed Sep 17 2014 - 04:26:42 EST

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.kweh@xxxxxxxxx>
Signed-off-by: Weike Chen <alvin.chen@xxxxxxxxx>
---
drivers/gpio/Kconfig | 1 -
drivers/gpio/gpio-dwapb.c | 224 ++++++++++++++++++++++--------
include/linux/platform_data/gpio-dwapb.h | 32 +++++
3 files changed, 199 insertions(+), 58 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..27466b5 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -21,6 +21,8 @@
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
+#include <linux/platform_data/gpio-dwapb.h>
+#include <linux/slab.h>

#define GPIO_SWPORTA_DR 0x00
#define GPIO_SWPORTA_DDR 0x04
@@ -84,11 +86,10 @@ static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
writel(v, gpio->regs + GPIO_INT_POLARITY);
}

-static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
+static u32 dwapb_do_irq(struct dwapb_gpio *gpio)
{
- struct dwapb_gpio *gpio = irq_get_handler_data(irq);
- struct irq_chip *chip = irq_desc_get_chip(desc);
u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS);
+ u32 ret = irq_status;

while (irq_status) {
int hwirq = fls(irq_status) - 1;
@@ -102,6 +103,16 @@ static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
dwapb_toggle_trigger(gpio, hwirq);
}

+ return ret;
+}
+
+static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
+{
+ struct dwapb_gpio *gpio = irq_get_handler_data(irq);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+
+ dwapb_do_irq(gpio);
+
if (chip->irq_eoi)
chip->irq_eoi(irq_desc_get_irq_data(desc));
}
@@ -207,22 +218,26 @@ 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)
+{
+ u32 worked;
+ struct dwapb_gpio *gpio = dev_id;
+
+ worked = dwapb_do_irq(gpio);
+
+ return worked ? IRQ_HANDLED : IRQ_NONE;
+}
+
static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
- struct dwapb_gpio_port *port)
+ struct dwapb_gpio_port *port,
+ struct dwapb_port_property *pp)
{
struct gpio_chip *gc = &port->bgc.gc;
- struct device_node *node = gc->of_node;
- struct irq_chip_generic *irq_gc;
+ struct device_node *node = 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 +284,24 @@ 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 (!pp->irq_shared) {
+ irq_set_chained_handler(pp->irq, dwapb_irq_handler);
+ irq_set_handler_data(pp->irq, gpio);
+ } else {
+ /*
+ * Request a shared IRQ since where MFD would have devices
+ * using the same irq pin
+ */
+ err = devm_request_irq(gpio->dev, 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;
+ }
+ }

for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
irq_create_mapping(gpio->domain, hwirq);
@@ -296,57 +327,42 @@ 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_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;

- 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;
+#ifdef CONFIG_OF_GPIO
+ port->bgc.gc.of_node = pp->node;
+#endif
+ 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"))
- dwapb_configure_irqs(gpio, port);
+ if (pp->irq)
+ dwapb_configure_irqs(gpio, port, pp);

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;

@@ -362,25 +378,116 @@ static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
gpiochip_remove(&gpio->ports[m].bgc.gc);
}

+static struct dwapb_platform_data *
+dwapb_gpio_get_pdata_of(struct device *dev)
+{
+ struct device_node *node, *port_np;
+ struct dwapb_platform_data *pdata;
+ struct dwapb_port_property *pp;
+ int nports;
+ int i;
+
+ node = dev->of_node;
+ if (!IS_ENABLED(CONFIG_OF_GPIO) || !node)
+ return ERR_PTR(-ENODEV);
+
+ nports = of_get_child_count(node);
+ if (nports == 0)
+ return ERR_PTR(-ENODEV);
+
+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ pdata->properties = kcalloc(nports, sizeof(*pp), GFP_KERNEL);
+ if (!pdata->properties) {
+ kfree(pdata);
+ 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);
+ kfree(pdata->properties);
+ kfree(pdata);
+ 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;
+ }
+
+ /*
+ * Only port A can provide interrupts in all configurations of
+ * the IP.
+ */
+ 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);
+ }
+ }
+
+ pp->irq_shared = false;
+ pp->gpio_base = -1;
+ pp->name = port_np->full_name;
+ }
+
+ return pdata;
+}
+
+static inline void dwapb_free_pdata_of(struct dwapb_platform_data *pdata)
+{
+ if (!IS_ENABLED(CONFIG_OF_GPIO) || !pdata)
+ return;
+
+ kfree(pdata->properties);
+ kfree(pdata);
+}
+
static int dwapb_gpio_probe(struct platform_device *pdev)
{
+ unsigned int i;
struct resource *res;
struct dwapb_gpio *gpio;
- struct device_node *np;
int err;
- unsigned int offs = 0;
+ struct device *dev = &pdev->dev;
+ struct dwapb_platform_data *pdata = dev_get_platdata(dev);
+ bool is_pdata_alloc = !pdata;
+
+ if (is_pdata_alloc) {
+ pdata = dwapb_gpio_get_pdata_of(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ }

- gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
- if (!gpio)
- return -ENOMEM;
- gpio->dev = &pdev->dev;
+ if (!pdata->nports) {
+ err = -ENODEV;
+ goto out_err;
+ }

- gpio->nr_ports = of_get_child_count(pdev->dev.of_node);
- if (!gpio->nr_ports) {
- err = -EINVAL;
+ gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio) {
+ err = -ENOMEM;
goto out_err;
}
- gpio->ports = devm_kzalloc(&pdev->dev, gpio->nr_ports *
+ gpio->dev = &pdev->dev;
+ gpio->nr_ports = pdata->nports;
+
+ gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports,
sizeof(*gpio->ports), GFP_KERNEL);
if (!gpio->ports) {
err = -ENOMEM;
@@ -394,20 +501,23 @@ 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 < gpio->nr_ports; i++) {
+ err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
if (err)
goto out_unregister;
}
platform_set_drvdata(pdev, gpio);

- return 0;
+ goto out_err;

out_unregister:
dwapb_gpio_unregister(gpio);
dwapb_irq_teardown(gpio);

out_err:
+ if (is_pdata_alloc)
+ dwapb_free_pdata_of(pdata);
+
return err;
}

diff --git a/include/linux/platform_data/gpio-dwapb.h b/include/linux/platform_data/gpio-dwapb.h
new file mode 100644
index 0000000..28702c8
--- /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_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_platform_data {
+ struct dwapb_port_property *properties;
+ unsigned int nports;
+};
+
+#endif
--
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/