[09/16] gpio: add driver for Atheros AR5312 SoC GPIO controller
diff mbox

Message ID 1411929195-23775-10-git-send-email-ryazanov.s.a@gmail.com
State Rejected
Headers show

Commit Message

Sergey Ryazanov Sept. 28, 2014, 6:33 p.m. UTC
Atheros AR5312 SoC have a builtin GPIO controller, which could be accessed
via memory mapped registers. This patch adds new driver for them.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
---

Changes since RFC:
  - move device registration to separate patch

 drivers/gpio/Kconfig       |   7 +++
 drivers/gpio/Makefile      |   1 +
 drivers/gpio/gpio-ar5312.c | 121 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+)
 create mode 100644 drivers/gpio/gpio-ar5312.c

Comments

Linus Walleij Oct. 15, 2014, 7:33 a.m. UTC | #1
On Sun, Sep 28, 2014 at 8:33 PM, Sergey Ryazanov <ryazanov.s.a@gmail.com> wrote:

> Atheros AR5312 SoC have a builtin GPIO controller, which could be accessed
> via memory mapped registers. This patch adds new driver for them.
>
> Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Alexandre Courbot <gnurou@gmail.com>
> Cc: linux-gpio@vger.kernel.org

This driver is extremely simple. You should be able to use
drivers/gpio/gpio-generic.c for this.

NAK for the time being.

> +#define AR5312_GPIO_CR_INT(x)  (1 << ((x)+8))  /* mask for interrupt */

Seems to be unused.
For a MMIO gpiochip using interrupts it's still possible
to use gpio-generic.c as a library-

> +#define AR5312_GPIO_CR_UART(x) (1 << ((x)+16)) /* uart multiplex */

That sounds like pin control business.

Yours,
Linus Walleij
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Patch
diff mbox

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 9de1515..7ce411b 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -112,6 +112,13 @@  config GPIO_MAX730X
 
 comment "Memory mapped GPIO drivers:"
 
+config GPIO_AR5312
+	bool "AR5312 SoC GPIO support"
+	default y if SOC_AR5312
+	depends on SOC_AR5312
+	help
+	  Say yes here to enable GPIO support for Atheros AR5312/AR2312+ SoCs.
+
 config GPIO_CLPS711X
 	tristate "CLPS711X GPIO support"
 	depends on ARCH_CLPS711X || COMPILE_TEST
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 5d024e3..fae00f4 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -17,6 +17,7 @@  obj-$(CONFIG_GPIO_ADNP)		+= gpio-adnp.o
 obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp5520.o
 obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
 obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
+obj-$(CONFIG_GPIO_AR5312)	+= gpio-ar5312.o
 obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
 obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o
 obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-ar5312.c b/drivers/gpio/gpio-ar5312.c
new file mode 100644
index 0000000..27adb61
--- /dev/null
+++ b/drivers/gpio/gpio-ar5312.c
@@ -0,0 +1,121 @@ 
+/*
+ * 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.
+ *
+ * Copyright (C) 2003 Atheros Communications, Inc.,  All Rights Reserved.
+ * Copyright (C) 2006 FON Technology, SL.
+ * Copyright (C) 2006 Imre Kaloz <kaloz@openwrt.org>
+ * Copyright (C) 2006-2009 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2012 Alexandros C. Couloumbis <alex@ozo.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+
+#define DRIVER_NAME	"ar5312-gpio"
+
+#define AR5312_GPIO_DO		0x00		/* output register */
+#define AR5312_GPIO_DI		0x04		/* intput register */
+#define AR5312_GPIO_CR		0x08		/* control register */
+
+#define AR5312_GPIO_CR_M(x)	(1 << (x))	/* mask for i/o */
+#define AR5312_GPIO_CR_O(x)	(0 << (x))	/* mask for output */
+#define AR5312_GPIO_CR_I(x)	(1 << (x))	/* mask for input */
+#define AR5312_GPIO_CR_INT(x)	(1 << ((x)+8))	/* mask for interrupt */
+#define AR5312_GPIO_CR_UART(x)	(1 << ((x)+16))	/* uart multiplex */
+
+#define AR5312_GPIO_NUM		8
+
+static void __iomem *ar5312_mem;
+
+static inline u32 ar5312_gpio_reg_read(unsigned reg)
+{
+	return __raw_readl(ar5312_mem + reg);
+}
+
+static inline void ar5312_gpio_reg_write(unsigned reg, u32 val)
+{
+	__raw_writel(val, ar5312_mem + reg);
+}
+
+static inline void ar5312_gpio_reg_mask(unsigned reg, u32 mask, u32 val)
+{
+	ar5312_gpio_reg_write(reg, (ar5312_gpio_reg_read(reg) & ~mask) | val);
+}
+
+static int ar5312_gpio_get_val(struct gpio_chip *chip, unsigned gpio)
+{
+	return (ar5312_gpio_reg_read(AR5312_GPIO_DI) >> gpio) & 1;
+}
+
+static void ar5312_gpio_set_val(struct gpio_chip *chip, unsigned gpio, int val)
+{
+	u32 reg = ar5312_gpio_reg_read(AR5312_GPIO_DO);
+
+	reg = val ? reg | (1 << gpio) : reg & ~(1 << gpio);
+	ar5312_gpio_reg_write(AR5312_GPIO_DO, reg);
+}
+
+static int ar5312_gpio_dir_in(struct gpio_chip *chip, unsigned gpio)
+{
+	ar5312_gpio_reg_mask(AR5312_GPIO_CR, 0, 1 << gpio);
+	return 0;
+}
+
+static int ar5312_gpio_dir_out(struct gpio_chip *chip, unsigned gpio, int val)
+{
+	ar5312_gpio_reg_mask(AR5312_GPIO_CR, 1 << gpio, 0);
+	ar5312_gpio_set_val(chip, gpio, val);
+	return 0;
+}
+
+static struct gpio_chip ar5312_gpio_chip = {
+	.label			= DRIVER_NAME,
+	.direction_input	= ar5312_gpio_dir_in,
+	.direction_output	= ar5312_gpio_dir_out,
+	.set			= ar5312_gpio_set_val,
+	.get			= ar5312_gpio_get_val,
+	.base			= 0,
+	.ngpio			= AR5312_GPIO_NUM,
+};
+
+static int ar5312_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	int ret;
+
+	if (ar5312_mem)
+		return -EBUSY;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ar5312_mem = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ar5312_mem))
+		return PTR_ERR(ar5312_mem);
+
+	ar5312_gpio_chip.dev = dev;
+	ret = gpiochip_add(&ar5312_gpio_chip);
+	if (ret) {
+		dev_err(dev, "failed to add gpiochip\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver ar5312_gpio_driver = {
+	.probe = ar5312_gpio_probe,
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	}
+};
+
+static int __init ar5312_gpio_init(void)
+{
+	return platform_driver_register(&ar5312_gpio_driver);
+}
+subsys_initcall(ar5312_gpio_init);