[RESEND PATCH v3 0/4] cbus/retu drivers

[RESEND PATCH v3 0/4] cbus/retu drivers

[Aaro Koskinen]

This patch set introduces drivers for CBUS access and Retu multifunction
chip found on Nokia Internet Tablets (770, N800, N810). It would be
nice get these patches applied as the functionality of these devices is
severely lacking without Retu. E.g. watchdog support is mandatory at
least on Nokia N800, you cannot currently run the mainline kernel for
longer than ~60 seconds (there is no way to disable the watchdog).

Drivers originate from linux-omap cbus branch and have been cleaned
up/rewritten around i2c and MFD core.

Patches have been tested on top of 3.7-rc5 with Nokia N800 (watchdog
feeding works, power off shuts down the device, power button triggers
IRQs and input events, loading and unloading retu-pwrbutton module in a
loop while manically pressing the power button does not crash the kernel).

Changes since the second version (https://lkml.org/lkml/2012/10/31/520):
	- i2c-cbus:
		- move i2c-cbus.h under linux/platform_data
	- retu-mfd
		- replace "&retu_pwrbutton_res[0]" expression with simpler
		  "retu_pwrbutton_res".
	- retu-pwrbutton:
		- eliminate struct retu_pwrbutton
		- delete checks for duplicate events
		- rework probe to avoid races
		- disable IRQ before unregister in retu_pwrbutton_remove() to
		  avoid races
		- eliminate double free in retu_pwrbutton_remove()
		- add .owner = THIS_MODULE

Changes since the first version (https://lkml.org/lkml/2012/9/3/265):
	- i2c-cbus:
		- use devres
		- improve comments
		- simplify and delete redundant code
		- refactoring & bug fixes on error handling
		- discard "input" parameter from cbus_send_bit/data()
	- retu-mfd:
		- use devres
		- use regmap
	- retu_wdt: use devres
	- retu-pwrbutton: use devres

Changes since the RFC version
(http://marc.info/?l=linux-omap&m=134618967116737&w=2):
        - added DT support for getting i2c-cbus GPIO pins
        - merged n8x0 board file changes into i2c-cbus patch
        - corrected typo in Kconfig for MFD_RETU
        - added power off functionality to retu-mfd
        - added IRQ functionality to retu-mfd
        - added power button key driver
        - some cleanups

Aaro Koskinen (4):
  i2c: introduce i2c-cbus driver
  mfd: introduce retu-mfd driver
  watchdog: introduce retu_wdt driver
  input: misc: introduce retu-pwrbutton

 arch/arm/mach-omap2/board-n8x0.c       |   42 +++++
 drivers/i2c/busses/Kconfig             |   10 +
 drivers/i2c/busses/Makefile            |    1 +
 drivers/i2c/busses/i2c-cbus.c          |  300 ++++++++++++++++++++++++++++++++
 drivers/input/misc/Kconfig             |   10 +
 drivers/input/misc/Makefile            |    1 +
 drivers/input/misc/retu-pwrbutton.c    |  102 +++++++++++
 drivers/mfd/Kconfig                    |    9 +
 drivers/mfd/Makefile                   |    1 +
 drivers/mfd/retu-mfd.c                 |  264 ++++++++++++++++++++++++++++
 drivers/watchdog/Kconfig               |   12 ++
 drivers/watchdog/Makefile              |    1 +
 drivers/watchdog/retu_wdt.c            |  178 +++++++++++++++++++
 include/linux/mfd/retu.h               |   22 +++
 include/linux/platform_data/i2c-cbus.h |   27 +++
 15 files changed, 980 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-cbus.c
 create mode 100644 drivers/input/misc/retu-pwrbutton.c
 create mode 100644 drivers/mfd/retu-mfd.c
 create mode 100644 drivers/watchdog/retu_wdt.c
 create mode 100644 include/linux/mfd/retu.h
 create mode 100644 include/linux/platform_data/i2c-cbus.h

-- 
1.7.2.5

[RESEND PATCH v3 1/4] i2c: introduce i2c-cbus driver

[Aaro Koskinen]

Add i2c driver to enable access to devices behind CBUS on Nokia Internet
Tablets.

The patch also adds CBUS I2C configuration for N8x0 which is one of the
users of this driver.

Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Acked-by: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>
Acked-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Aaro Koskinen <aaro.koskinen-X3B1VOXEql0@public.gmane.org>
Cc: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
 arch/arm/mach-omap2/board-n8x0.c       |   42 +++++
 drivers/i2c/busses/Kconfig             |   10 +
 drivers/i2c/busses/Makefile            |    1 +
 drivers/i2c/busses/i2c-cbus.c          |  300 ++++++++++++++++++++++++++++++++
 include/linux/platform_data/i2c-cbus.h |   27 +++
 5 files changed, 380 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-cbus.c
 create mode 100644 include/linux/platform_data/i2c-cbus.h

diff --git a/arch/arm/mach-omap2/board-n8x0.c b/arch/arm/mach-omap2/board-n8x0.c
index d95f727..8e8a09d 100644
--- a/arch/arm/mach-omap2/board-n8x0.c
+++ b/arch/arm/mach-omap2/board-n8x0.c
@@ -16,10 +16,12 @@
 #include <linux/gpio.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/irq.h>
 #include <linux/stddef.h>
 #include <linux/i2c.h>
 #include <linux/spi/spi.h>
 #include <linux/usb/musb.h>
+#include <linux/platform_data/i2c-cbus.h>
 #include <linux/platform_data/spi-omap2-mcspi.h>
 #include <linux/platform_data/mtd-onenand-omap2.h>
 #include <sound/tlv320aic3x.h>
@@ -39,6 +41,45 @@
 #define TUSB6010_GPIO_ENABLE	0
 #define TUSB6010_DMACHAN	0x3f
 
+#if defined(CONFIG_I2C_CBUS) || defined(CONFIG_I2C_CBUS_MODULE)
+static struct i2c_cbus_platform_data n8x0_cbus_data = {
+	.clk_gpio = 66,
+	.dat_gpio = 65,
+	.sel_gpio = 64,
+};
+
+static struct platform_device n8x0_cbus_device = {
+	.name	= "i2c-cbus",
+	.id	= 3,
+	.dev	= {
+		.platform_data = &n8x0_cbus_data,
+	},
+};
+
+static struct i2c_board_info n8x0_i2c_board_info_3[] __initdata = {
+	{
+		I2C_BOARD_INFO("retu-mfd", 0x01),
+	},
+};
+
+static void __init n8x0_cbus_init(void)
+{
+	const int retu_irq_gpio = 108;
+
+	if (gpio_request_one(retu_irq_gpio, GPIOF_IN, "Retu IRQ"))
+		return;
+	irq_set_irq_type(gpio_to_irq(retu_irq_gpio), IRQ_TYPE_EDGE_RISING);
+	n8x0_i2c_board_info_3[0].irq = gpio_to_irq(retu_irq_gpio);
+	i2c_register_board_info(3, n8x0_i2c_board_info_3,
+				ARRAY_SIZE(n8x0_i2c_board_info_3));
+	platform_device_register(&n8x0_cbus_device);
+}
+#else /* CONFIG_I2C_CBUS */
+static void __init n8x0_cbus_init(void)
+{
+}
+#endif /* CONFIG_I2C_CBUS */
+
 #if defined(CONFIG_USB_MUSB_TUSB6010) || defined(CONFIG_USB_MUSB_TUSB6010_MODULE)
 /*
  * Enable or disable power to TUSB6010. When enabling, turn on 3.3 V and
@@ -677,6 +718,7 @@ static void __init n8x0_init_machine(void)
 	gpmc_onenand_init(board_onenand_data);
 	n8x0_mmc_init();
 	n8x0_usb_init();
+	n8x0_cbus_init();
 }
 
 MACHINE_START(NOKIA_N800, "Nokia N800")
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index e9df461..fdfc222 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -337,6 +337,16 @@ config I2C_BLACKFIN_TWI_CLK_KHZ
 	help
 	  The unit of the TWI clock is kHz.
 
+config I2C_CBUS
+	tristate "CBUS I2C driver"
+	depends on GENERIC_GPIO
+	help
+	  Support for CBUS access using I2C API. Mostly relevant for Nokia
+	  Internet Tablets (770, N800 and N810).
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-cbus.
+
 config I2C_CPM
 	tristate "Freescale CPM1 or CPM2 (MPC8xx/826x)"
 	depends on (CPM1 || CPM2) && OF_I2C
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 395b516..0a71da5 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_I2C_POWERMAC)	+= i2c-powermac.o
 obj-$(CONFIG_I2C_AT91)		+= i2c-at91.o
 obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
 obj-$(CONFIG_I2C_BLACKFIN_TWI)	+= i2c-bfin-twi.o
+obj-$(CONFIG_I2C_CBUS)		+= i2c-cbus.o
 obj-$(CONFIG_I2C_CPM)		+= i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
 obj-$(CONFIG_I2C_DESIGNWARE_CORE)	+= i2c-designware-core.o
diff --git a/drivers/i2c/busses/i2c-cbus.c b/drivers/i2c/busses/i2c-cbus.c
new file mode 100644
index 0000000..e6086cf
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cbus.c
@@ -0,0 +1,300 @@
+/*
+ * CBUS I2C driver for Nokia Internet Tablets.
+ *
+ * Copyright (C) 2004-2010 Nokia Corporation
+ *
+ * Based on code written by Juha Yrjölä, David Weinehall, Mikko Ylinen and
+ * Felipe Balbi. Converted to I2C driver by Aaro Koskinen.
+ *
+ * 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.
+ *
+ * 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/io.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/i2c-cbus.h>
+
+/*
+ * Bit counts are derived from Nokia implementation. These should be checked
+ * if other CBUS implementations appear.
+ */
+#define CBUS_ADDR_BITS	3
+#define CBUS_REG_BITS	5
+
+struct cbus_host {
+	spinlock_t	lock;		/* host lock */
+	struct device	*dev;
+	int		clk_gpio;
+	int		dat_gpio;
+	int		sel_gpio;
+};
+
+/**
+ * cbus_send_bit - sends one bit over the bus
+ * @host: the host we're using
+ * @bit: one bit of information to send
+ */
+static void cbus_send_bit(struct cbus_host *host, unsigned bit)
+{
+	gpio_set_value(host->dat_gpio, bit ? 1 : 0);
+	gpio_set_value(host->clk_gpio, 1);
+	gpio_set_value(host->clk_gpio, 0);
+}
+
+/**
+ * cbus_send_data - sends @len amount of data over the bus
+ * @host: the host we're using
+ * @data: the data to send
+ * @len: size of the transfer
+ */
+static void cbus_send_data(struct cbus_host *host, unsigned data, unsigned len)
+{
+	int i;
+
+	for (i = len; i > 0; i--)
+		cbus_send_bit(host, data & (1 << (i - 1)));
+}
+
+/**
+ * cbus_receive_bit - receives one bit from the bus
+ * @host: the host we're using
+ */
+static int cbus_receive_bit(struct cbus_host *host)
+{
+	int ret;
+
+	gpio_set_value(host->clk_gpio, 1);
+	ret = gpio_get_value(host->dat_gpio);
+	gpio_set_value(host->clk_gpio, 0);
+	return ret;
+}
+
+/**
+ * cbus_receive_word - receives 16-bit word from the bus
+ * @host: the host we're using
+ */
+static int cbus_receive_word(struct cbus_host *host)
+{
+	int ret = 0;
+	int i;
+
+	for (i = 16; i > 0; i--) {
+		int bit = cbus_receive_bit(host);
+
+		if (bit < 0)
+			return bit;
+
+		if (bit)
+			ret |= 1 << (i - 1);
+	}
+	return ret;
+}
+
+/**
+ * cbus_transfer - transfers data over the bus
+ * @host: the host we're using
+ * @rw: read/write flag
+ * @dev: device address
+ * @reg: register address
+ * @data: if @rw == I2C_SBUS_WRITE data to send otherwise 0
+ */
+static int cbus_transfer(struct cbus_host *host, char rw, unsigned dev,
+			 unsigned reg, unsigned data)
+{
+	unsigned long flags;
+	int ret;
+
+	/* We don't want interrupts disturbing our transfer */
+	spin_lock_irqsave(&host->lock, flags);
+
+	/* Reset state and start of transfer, SEL stays down during transfer */
+	gpio_set_value(host->sel_gpio, 0);
+
+	/* Set the DAT pin to output */
+	gpio_direction_output(host->dat_gpio, 1);
+
+	/* Send the device address */
+	cbus_send_data(host, dev, CBUS_ADDR_BITS);
+
+	/* Send the rw flag */
+	cbus_send_bit(host, rw == I2C_SMBUS_READ);
+
+	/* Send the register address */
+	cbus_send_data(host, reg, CBUS_REG_BITS);
+
+	if (rw == I2C_SMBUS_WRITE) {
+		cbus_send_data(host, data, 16);
+		ret = 0;
+	} else {
+		ret = gpio_direction_input(host->dat_gpio);
+		if (ret) {
+			dev_dbg(host->dev, "failed setting direction\n");
+			goto out;
+		}
+		gpio_set_value(host->clk_gpio, 1);
+
+		ret = cbus_receive_word(host);
+		if (ret < 0) {
+			dev_dbg(host->dev, "failed receiving data\n");
+			goto out;
+		}
+	}
+
+	/* Indicate end of transfer, SEL goes up until next transfer */
+	gpio_set_value(host->sel_gpio, 1);
+	gpio_set_value(host->clk_gpio, 1);
+	gpio_set_value(host->clk_gpio, 0);
+
+out:
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	return ret;
+}
+
+static int cbus_i2c_smbus_xfer(struct i2c_adapter	*adapter,
+			       u16			addr,
+			       unsigned short		flags,
+			       char			read_write,
+			       u8			command,
+			       int			size,
+			       union i2c_smbus_data	*data)
+{
+	struct cbus_host *chost = i2c_get_adapdata(adapter);
+	int ret;
+
+	if (size != I2C_SMBUS_WORD_DATA)
+		return -EINVAL;
+
+	ret = cbus_transfer(chost, read_write == I2C_SMBUS_READ, addr,
+			    command, data->word);
+	if (ret < 0)
+		return ret;
+
+	if (read_write == I2C_SMBUS_READ)
+		data->word = ret;
+
+	return 0;
+}
+
+static u32 cbus_i2c_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA;
+}
+
+static const struct i2c_algorithm cbus_i2c_algo = {
+	.smbus_xfer	= cbus_i2c_smbus_xfer,
+	.functionality	= cbus_i2c_func,
+};
+
+static int cbus_i2c_remove(struct platform_device *pdev)
+{
+	struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+
+	return i2c_del_adapter(adapter);
+}
+
+static int cbus_i2c_probe(struct platform_device *pdev)
+{
+	struct i2c_adapter *adapter;
+	struct cbus_host *chost;
+	int ret;
+
+	adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter),
+			       GFP_KERNEL);
+	if (!adapter)
+		return -ENOMEM;
+
+	chost = devm_kzalloc(&pdev->dev, sizeof(*chost), GFP_KERNEL);
+	if (!chost)
+		return -ENOMEM;
+
+	if (pdev->dev.of_node) {
+		struct device_node *dnode = pdev->dev.of_node;
+		if (of_gpio_count(dnode) != 3)
+			return -ENODEV;
+		chost->clk_gpio = of_get_gpio(dnode, 0);
+		chost->dat_gpio = of_get_gpio(dnode, 1);
+		chost->sel_gpio = of_get_gpio(dnode, 2);
+	} else if (pdev->dev.platform_data) {
+		struct i2c_cbus_platform_data *pdata = pdev->dev.platform_data;
+		chost->clk_gpio = pdata->clk_gpio;
+		chost->dat_gpio = pdata->dat_gpio;
+		chost->sel_gpio = pdata->sel_gpio;
+	} else {
+		return -ENODEV;
+	}
+
+	adapter->owner		= THIS_MODULE;
+	adapter->class		= I2C_CLASS_HWMON;
+	adapter->dev.parent	= &pdev->dev;
+	adapter->nr		= pdev->id;
+	adapter->timeout	= HZ;
+	adapter->algo		= &cbus_i2c_algo;
+	strlcpy(adapter->name, "CBUS I2C adapter", sizeof(adapter->name));
+
+	spin_lock_init(&chost->lock);
+	chost->dev = &pdev->dev;
+
+	ret = devm_gpio_request_one(&pdev->dev, chost->clk_gpio,
+				    GPIOF_OUT_INIT_LOW, "CBUS clk");
+	if (ret)
+		return ret;
+
+	ret = devm_gpio_request_one(&pdev->dev, chost->dat_gpio, GPIOF_IN,
+				    "CBUS data");
+	if (ret)
+		return ret;
+
+	ret = devm_gpio_request_one(&pdev->dev, chost->sel_gpio,
+				    GPIOF_OUT_INIT_HIGH, "CBUS sel");
+	if (ret)
+		return ret;
+
+	i2c_set_adapdata(adapter, chost);
+	platform_set_drvdata(pdev, adapter);
+
+	return i2c_add_numbered_adapter(adapter);
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id i2c_cbus_dt_ids[] = {
+	{ .compatible = "i2c-cbus", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, i2c_cbus_dt_ids);
+#endif
+
+static struct platform_driver cbus_i2c_driver = {
+	.probe	= cbus_i2c_probe,
+	.remove	= cbus_i2c_remove,
+	.driver	= {
+		.owner	= THIS_MODULE,
+		.name	= "i2c-cbus",
+	},
+};
+module_platform_driver(cbus_i2c_driver);
+
+MODULE_ALIAS("platform:i2c-cbus");
+MODULE_DESCRIPTION("CBUS I2C driver");
+MODULE_AUTHOR("Juha Yrjölä");
+MODULE_AUTHOR("David Weinehall");
+MODULE_AUTHOR("Mikko Ylinen");
+MODULE_AUTHOR("Felipe Balbi");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen-X3B1VOXEql0@public.gmane.org>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_data/i2c-cbus.h b/include/linux/platform_data/i2c-cbus.h
new file mode 100644
index 0000000..636d726
--- /dev/null
+++ b/include/linux/platform_data/i2c-cbus.h
@@ -0,0 +1,27 @@
+/*
+ * i2c-cbus.h - CBUS I2C platform_data definition
+ *
+ * Copyright (C) 2004-2009 Nokia Corporation
+ *
+ * Written by Felipe Balbi and Aaro Koskinen.
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#ifndef __INCLUDE_LINUX_I2C_CBUS_H
+#define __INCLUDE_LINUX_I2C_CBUS_H
+
+struct i2c_cbus_platform_data {
+	int dat_gpio;
+	int clk_gpio;
+	int sel_gpio;
+};
+
+#endif /* __INCLUDE_LINUX_I2C_CBUS_H */
-- 
1.7.2.5

[RESEND PATCH v3 2/4] mfd: introduce retu-mfd driver

[Aaro Koskinen]

Retu is a multi-function device found on Nokia Internet Tablets
implementing at least watchdog, RTC, headset detection and power button
functionality.

This patch implements minimum functionality providing register access,
IRQ handling and power off functions.

Cc: sameo@linux.intel.com
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
---
 drivers/mfd/Kconfig      |    9 ++
 drivers/mfd/Makefile     |    1 +
 drivers/mfd/retu-mfd.c   |  264 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/retu.h |   22 ++++
 4 files changed, 296 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/retu-mfd.c
 create mode 100644 include/linux/mfd/retu.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index acab3ef..7528c5e 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1044,6 +1044,15 @@ config MFD_PALMAS
 	  If you say yes here you get support for the Palmas
 	  series of PMIC chips from Texas Instruments.
 
+config MFD_RETU
+	tristate "Support for Retu multi-function device"
+	select MFD_CORE
+	depends on I2C
+	select REGMAP_IRQ
+	help
+	  Retu is a multi-function device found on Nokia Internet Tablets
+	  (770, N800 and N810).
+
 endmenu
 endif
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d8ccb63..ad7879f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -138,3 +138,4 @@ obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
 obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
 obj-$(CONFIG_MFD_SYSCON)	+= syscon.o
 obj-$(CONFIG_MFD_LM3533)	+= lm3533-core.o lm3533-ctrlbank.o
+obj-$(CONFIG_MFD_RETU)		+= retu-mfd.o
diff --git a/drivers/mfd/retu-mfd.c b/drivers/mfd/retu-mfd.c
new file mode 100644
index 0000000..7ff4a37
--- /dev/null
+++ b/drivers/mfd/retu-mfd.c
@@ -0,0 +1,264 @@
+/*
+ * Retu MFD driver
+ *
+ * Copyright (C) 2004, 2005 Nokia Corporation
+ *
+ * Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen.
+ * Rewritten by Aaro Koskinen.
+ *
+ * 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.
+ *
+ * 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/err.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/retu.h>
+#include <linux/interrupt.h>
+#include <linux/moduleparam.h>
+
+/* Registers */
+#define RETU_REG_ASICR		0x00		/* ASIC ID and revision */
+#define RETU_REG_ASICR_VILMA	(1 << 7)	/* Bit indicating Vilma */
+#define RETU_REG_IDR		0x01		/* Interrupt ID */
+#define RETU_REG_IMR		0x02		/* Interrupt mask */
+
+/* Interrupt sources */
+#define RETU_INT_PWR		0		/* Power button */
+
+struct retu_dev {
+	struct regmap			*regmap;
+	struct device			*dev;
+	struct mutex			mutex;
+	struct regmap_irq_chip_data	*irq_data;
+};
+
+static struct resource retu_pwrbutton_res[] = {
+	{
+		.name	= "retu-pwrbutton",
+		.start	= RETU_INT_PWR,
+		.end	= RETU_INT_PWR,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct mfd_cell retu_devs[] = {
+	{
+		.name		= "retu-wdt"
+	},
+	{
+		.name		= "retu-pwrbutton",
+		.resources	= retu_pwrbutton_res,
+		.num_resources	= ARRAY_SIZE(retu_pwrbutton_res),
+	}
+};
+
+static struct regmap_irq retu_irqs[] = {
+	[RETU_INT_PWR] = {
+		.mask = 1 << RETU_INT_PWR,
+	}
+};
+
+static struct regmap_irq_chip retu_irq_chip = {
+	.name		= "RETU",
+	.irqs		= retu_irqs,
+	.num_irqs	= ARRAY_SIZE(retu_irqs),
+	.num_regs	= 1,
+	.status_base	= RETU_REG_IDR,
+	.mask_base	= RETU_REG_IMR,
+	.ack_base	= RETU_REG_IDR,
+};
+
+/* Retu device registered for the power off. */
+static struct retu_dev *retu_pm_power_off;
+
+int retu_read(struct retu_dev *rdev, u8 reg)
+{
+	int ret;
+	int value;
+
+	mutex_lock(&rdev->mutex);
+	ret = regmap_read(rdev->regmap, reg, &value);
+	mutex_unlock(&rdev->mutex);
+
+	return ret ? ret : value;
+}
+EXPORT_SYMBOL_GPL(retu_read);
+
+int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
+{
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+	ret = regmap_write(rdev->regmap, reg, data);
+	mutex_unlock(&rdev->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(retu_write);
+
+static void retu_power_off(void)
+{
+	struct retu_dev *rdev = retu_pm_power_off;
+	int reg;
+
+	mutex_lock(&retu_pm_power_off->mutex);
+
+	/* Ignore power button state */
+	regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
+	regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2);
+
+	/* Expire watchdog immediately */
+	regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);
+
+	/* Wait for poweroff */
+	for (;;)
+		cpu_relax();
+
+	mutex_unlock(&retu_pm_power_off->mutex);
+}
+
+static int retu_regmap_read(void *context, const void *reg, size_t reg_size,
+			    void *val, size_t val_size)
+{
+	int ret;
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	BUG_ON(reg_size != 1 || val_size != 2);
+
+	ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg);
+	if (ret < 0)
+		return ret;
+
+	*(u16 *)val = ret;
+	return 0;
+}
+
+static int retu_regmap_write(void *context, const void *data, size_t count)
+{
+	u8 reg;
+	u16 val;
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	BUG_ON(count != sizeof(reg) + sizeof(val));
+	memcpy(&reg, data, sizeof(reg));
+	memcpy(&val, data + sizeof(reg), sizeof(val));
+	return i2c_smbus_write_word_data(i2c, reg, val);
+}
+
+static struct regmap_bus retu_bus = {
+	.read = retu_regmap_read,
+	.write = retu_regmap_write,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static struct regmap_config retu_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+};
+
+static int __devinit retu_probe(struct i2c_client *i2c,
+				const struct i2c_device_id *id)
+{
+	struct retu_dev *rdev;
+	int ret;
+
+	rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
+	if (rdev == NULL)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, rdev);
+	rdev->dev = &i2c->dev;
+	mutex_init(&rdev->mutex);
+	rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
+					&retu_config);
+	if (IS_ERR(rdev->regmap))
+		return PTR_ERR(rdev->regmap);
+
+	ret = retu_read(rdev, RETU_REG_ASICR);
+	if (ret < 0) {
+		dev_err(rdev->dev, "could not read Retu revision: %d\n", ret);
+		return ret;
+	}
+
+	dev_info(rdev->dev, "Retu%s v%d.%d found\n",
+		 (ret & RETU_REG_ASICR_VILMA) ? " & Vilma" : "",
+		 (ret >> 4) & 0x7, ret & 0xf);
+
+	/* Mask all RETU interrupts. */
+	ret = retu_write(rdev, RETU_REG_IMR, 0xffff);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
+				  &retu_irq_chip, &rdev->irq_data);
+	if (ret < 0)
+		return ret;
+
+	ret = mfd_add_devices(rdev->dev, -1, retu_devs, ARRAY_SIZE(retu_devs),
+			      NULL, regmap_irq_chip_get_base(rdev->irq_data),
+			      NULL);
+	if (ret < 0) {
+		regmap_del_irq_chip(i2c->irq, rdev->irq_data);
+		return ret;
+	}
+
+	if (!pm_power_off) {
+		retu_pm_power_off = rdev;
+		pm_power_off	  = retu_power_off;
+	}
+
+	return 0;
+}
+
+static int __devexit retu_remove(struct i2c_client *i2c)
+{
+	struct retu_dev *rdev = i2c_get_clientdata(i2c);
+
+	if (retu_pm_power_off == rdev) {
+		pm_power_off	  = NULL;
+		retu_pm_power_off = NULL;
+	}
+	mfd_remove_devices(rdev->dev);
+	regmap_del_irq_chip(i2c->irq, rdev->irq_data);
+
+	return 0;
+}
+
+static const struct i2c_device_id retu_id[] = {
+	{ "retu-mfd", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, retu_id);
+
+static struct i2c_driver retu_driver = {
+	.driver		= {
+		.name = "retu-mfd",
+		.owner = THIS_MODULE,
+	},
+	.probe		= retu_probe,
+	.remove		= retu_remove,
+	.id_table	= retu_id,
+};
+module_i2c_driver(retu_driver);
+
+MODULE_DESCRIPTION("Retu MFD driver");
+MODULE_AUTHOR("Juha Yrjölä");
+MODULE_AUTHOR("David Weinehall");
+MODULE_AUTHOR("Mikko Ylinen");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/retu.h b/include/linux/mfd/retu.h
new file mode 100644
index 0000000..1e2715d
--- /dev/null
+++ b/include/linux/mfd/retu.h
@@ -0,0 +1,22 @@
+/*
+ * Retu MFD driver interface
+ *
+ * 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.
+ */
+
+#ifndef __LINUX_MFD_RETU_H
+#define __LINUX_MFD_RETU_H
+
+struct retu_dev;
+
+int retu_read(struct retu_dev *, u8);
+int retu_write(struct retu_dev *, u8, u16);
+
+/* Registers */
+#define RETU_REG_WATCHDOG	0x17		/* Watchdog */
+#define RETU_REG_CC1		0x0d		/* Common control register 1 */
+#define RETU_REG_STATUS		0x16		/* Status register */
+
+#endif /* __LINUX_MFD_RETU_H */
-- 
1.7.2.5

[RESEND PATCH v3 3/4] watchdog: introduce retu_wdt driver

[Aaro Koskinen]

Introduce Retu watchdog driver.

Cc: linux-watchdog@vger.kernel.org
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Wim Van Sebroeck <wim@iguana.be>
---
 drivers/watchdog/Kconfig    |   12 +++
 drivers/watchdog/Makefile   |    1 +
 drivers/watchdog/retu_wdt.c |  178 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 191 insertions(+), 0 deletions(-)
 create mode 100644 drivers/watchdog/retu_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index ad1bb93..c3a836d 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -352,6 +352,18 @@ config IMX2_WDT
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx2_wdt.
 
+config RETU_WATCHDOG
+	tristate "Retu watchdog"
+	depends on MFD_RETU
+	select WATCHDOG_CORE
+	help
+	  Retu watchdog driver for Nokia Internet Tablets (700, N800,
+	  N810). At least on N800 the watchdog cannot be disabled, so
+	  this driver is essential and you should enable it.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called retu_wdt.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 572b39b..d2f1c0c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
 obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
 obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
 obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
+obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/retu_wdt.c b/drivers/watchdog/retu_wdt.c
new file mode 100644
index 0000000..aeb0f39
--- /dev/null
+++ b/drivers/watchdog/retu_wdt.c
@@ -0,0 +1,178 @@
+/*
+ * Retu watchdog driver
+ *
+ * Copyright (C) 2004, 2005 Nokia Corporation
+ *
+ * Based on code written by Amit Kucheria and Michael Buesch.
+ * Rewritten by Aaro Koskinen.
+ *
+ * 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.
+ *
+ * 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/init.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/retu.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+
+/* Watchdog timer values in seconds */
+#define RETU_WDT_MAX_TIMER	63
+
+struct retu_wdt_dev {
+	struct retu_dev		*rdev;
+	struct device		*dev;
+	struct delayed_work	ping_work;
+};
+
+/*
+ * Since Retu watchdog cannot be disabled in hardware, we must kick it
+ * with a timer until userspace watchdog software takes over. If
+ * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.
+ */
+static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)
+{
+	retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
+	schedule_delayed_work(&wdev->ping_work,
+			round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));
+}
+
+static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)
+{
+	retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
+	cancel_delayed_work_sync(&wdev->ping_work);
+}
+
+static void retu_wdt_ping_work(struct work_struct *work)
+{
+	struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),
+						struct retu_wdt_dev, ping_work);
+	retu_wdt_ping_enable(wdev);
+}
+
+static int retu_wdt_start(struct watchdog_device *wdog)
+{
+	struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+	retu_wdt_ping_disable(wdev);
+
+	return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
+}
+
+static int retu_wdt_stop(struct watchdog_device *wdog)
+{
+	struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+	retu_wdt_ping_enable(wdev);
+
+	return 0;
+}
+
+static int retu_wdt_ping(struct watchdog_device *wdog)
+{
+	struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+	return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
+}
+
+static int retu_wdt_set_timeout(struct watchdog_device *wdog,
+				unsigned int timeout)
+{
+	struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+	wdog->timeout = timeout;
+	return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
+}
+
+static const struct watchdog_info retu_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = "Retu watchdog",
+};
+
+static const struct watchdog_ops retu_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= retu_wdt_start,
+	.stop		= retu_wdt_stop,
+	.ping		= retu_wdt_ping,
+	.set_timeout	= retu_wdt_set_timeout,
+};
+
+static int __devinit retu_wdt_probe(struct platform_device *pdev)
+{
+	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
+	bool nowayout = WATCHDOG_NOWAYOUT;
+	struct watchdog_device *retu_wdt;
+	struct retu_wdt_dev *wdev;
+	int ret;
+
+	retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL);
+	if (!retu_wdt)
+		return -ENOMEM;
+
+	wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
+	if (!wdev)
+		return -ENOMEM;
+
+	retu_wdt->info		= &retu_wdt_info;
+	retu_wdt->ops		= &retu_wdt_ops;
+	retu_wdt->timeout	= RETU_WDT_MAX_TIMER;
+	retu_wdt->min_timeout	= 0;
+	retu_wdt->max_timeout	= RETU_WDT_MAX_TIMER;
+
+	watchdog_set_drvdata(retu_wdt, wdev);
+	watchdog_set_nowayout(retu_wdt, nowayout);
+
+	wdev->rdev		= rdev;
+	wdev->dev		= &pdev->dev;
+
+	INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work);
+
+	ret = watchdog_register_device(retu_wdt);
+	if (ret < 0)
+		return ret;
+
+	if (nowayout)
+		retu_wdt_ping(retu_wdt);
+	else
+		retu_wdt_ping_enable(wdev);
+
+	platform_set_drvdata(pdev, retu_wdt);
+
+	return 0;
+}
+
+static int __devexit retu_wdt_remove(struct platform_device *pdev)
+{
+	struct watchdog_device *wdog = platform_get_drvdata(pdev);
+	struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+	watchdog_unregister_device(wdog);
+	cancel_delayed_work_sync(&wdev->ping_work);
+
+	return 0;
+}
+
+static struct platform_driver retu_wdt_driver = {
+	.probe		= retu_wdt_probe,
+	.remove		= __devexit_p(retu_wdt_remove),
+	.driver		= {
+		.name	= "retu-wdt",
+	},
+};
+module_platform_driver(retu_wdt_driver);
+
+MODULE_ALIAS("platform:retu-wdt");
+MODULE_DESCRIPTION("Retu watchdog");
+MODULE_AUTHOR("Amit Kucheria");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
+MODULE_LICENSE("GPL");
-- 
1.7.2.5

[RESEND PATCH v3 4/4] input: misc: introduce retu-pwrbutton

[Aaro Koskinen]

Add Retu power button driver.

Cc: linux-input@vger.kernel.org
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/misc/Kconfig          |   10 ++++
 drivers/input/misc/Makefile         |    1 +
 drivers/input/misc/retu-pwrbutton.c |  102 +++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/misc/retu-pwrbutton.c

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 7c0f1ec..e5be189 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -367,6 +367,16 @@ config INPUT_CM109
 	  To compile this driver as a module, choose M here: the module will be
 	  called cm109.
 
+config INPUT_RETU_PWRBUTTON
+	tristate "Retu Power button Driver"
+	depends on MFD_RETU
+	help
+	  Say Y here if you want to enable power key reporting via the
+	  Retu chips found in Nokia Internet Tablets (770, N800, N810).
+
+	  To compile this driver as a module, choose M here. The module will
+	  be called retu-pwrbutton.
+
 config INPUT_TWL4030_PWRBUTTON
 	tristate "TWL4030 Power button Driver"
 	depends on TWL4030_CORE
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 83fe6f5..4fbee0d 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_INPUT_PMIC8XXX_PWRKEY)	+= pmic8xxx-pwrkey.o
 obj-$(CONFIG_INPUT_POWERMATE)		+= powermate.o
 obj-$(CONFIG_INPUT_PWM_BEEPER)		+= pwm-beeper.o
 obj-$(CONFIG_INPUT_RB532_BUTTON)	+= rb532_button.o
+obj-$(CONFIG_INPUT_RETU_PWRBUTTON)	+= retu-pwrbutton.o
 obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER)	+= rotary_encoder.o
 obj-$(CONFIG_INPUT_SGI_BTNS)		+= sgi_btns.o
 obj-$(CONFIG_INPUT_SPARCSPKR)		+= sparcspkr.o
diff --git a/drivers/input/misc/retu-pwrbutton.c b/drivers/input/misc/retu-pwrbutton.c
new file mode 100644
index 0000000..043a12b
--- /dev/null
+++ b/drivers/input/misc/retu-pwrbutton.c
@@ -0,0 +1,102 @@
+/*
+ * Retu power button driver.
+ *
+ * Copyright (C) 2004-2010 Nokia Corporation
+ *
+ * Original code written by Ari Saastamoinen, Juha Yrjölä and Felipe Balbi.
+ * Rewritten by Aaro Koskinen.
+ *
+ * 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.
+ *
+ * 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/irq.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/retu.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#define RETU_STATUS_PWRONX (1 << 5)
+
+static irqreturn_t retu_pwrbutton_irq(int irq, void *_pwr)
+{
+	bool state;
+	struct input_dev *idev = _pwr;
+	struct retu_dev *rdev = input_get_drvdata(idev);
+
+	state = !(retu_read(rdev, RETU_REG_STATUS) & RETU_STATUS_PWRONX);
+	input_report_key(idev, KEY_POWER, state);
+	input_sync(idev);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit retu_pwrbutton_probe(struct platform_device *pdev)
+{
+	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
+	struct input_dev *idev;
+	int ret;
+
+	idev = input_allocate_device();
+	if (!idev)
+		return -ENOMEM;
+
+	idev->evbit[0]				= BIT_MASK(EV_KEY);
+	idev->keybit[BIT_WORD(KEY_POWER)]	= BIT_MASK(KEY_POWER);
+	idev->name				= "retu-pwrbutton";
+
+	platform_set_drvdata(pdev, idev);
+	input_set_drvdata(idev, rdev);
+
+	ret = input_register_device(idev);
+	if (ret < 0) {
+		input_free_device(idev);
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, platform_get_irq(pdev, 0),
+					NULL, retu_pwrbutton_irq, 0,
+					"retu-pwrbutton", idev);
+	if (ret < 0)
+		input_unregister_device(idev);
+
+	return ret;
+}
+
+static int __devexit retu_pwrbutton_remove(struct platform_device *pdev)
+{
+	struct input_dev *idev = platform_get_drvdata(pdev);
+
+	disable_irq(platform_get_irq(pdev, 0));
+	input_unregister_device(idev);
+
+	return 0;
+}
+
+static struct platform_driver retu_pwrbutton_driver = {
+	.probe		= retu_pwrbutton_probe,
+	.remove		= __devexit_p(retu_pwrbutton_remove),
+	.driver		= {
+		.name	= "retu-pwrbutton",
+		.owner	= THIS_MODULE,
+	},
+};
+module_platform_driver(retu_pwrbutton_driver);
+
+MODULE_ALIAS("platform:retu-pwrbutton");
+MODULE_DESCRIPTION("Retu Power Button");
+MODULE_AUTHOR("Ari Saastamoinen");
+MODULE_AUTHOR("Felipe Balbi");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
+MODULE_LICENSE("GPL");
-- 
1.7.2.5

Re: [RESEND PATCH v3 1/4] i2c: introduce i2c-cbus driver

[Wolfram Sang]

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On Mon, Nov 12, 2012 at 09:08:42PM +0200, Aaro Koskinen wrote:
> Add i2c driver to enable access to devices behind CBUS on Nokia Internet
> Tablets.
> 
> The patch also adds CBUS I2C configuration for N8x0 which is one of the
> users of this driver.
> 
> Cc: linux-i2c@vger.kernel.org
> Acked-by: Felipe Balbi <balbi@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Cc: Wolfram Sang <w.sang@pengutronix.de>

Mostly good, but the devicetree binding description is missing.
Please add a proper file with the same name as the driver to
Documentation/devicetree/bindings/i2c.
Also, it might make sense to rename the driver to i2c-cbus-gpio?

Thanks,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [RESEND PATCH v3 2/4] mfd: introduce retu-mfd driver

[Tony Lindgren]

* Aaro Koskinen <aaro.koskinen@iki.fi> [121112 11:11]:
> Retu is a multi-function device found on Nokia Internet Tablets
> implementing at least watchdog, RTC, headset detection and power button
> functionality.
> 
> This patch implements minimum functionality providing register access,
> IRQ handling and power off functions.

Samuel, you can pick this one up separately now that Wolfram has taken
the i2c-cbus driver.

Also, just noticed that this probably should depend on I2C_CBUS as this
chip will not communicate over other I2C adapters?

Regards,

Tony
 
> Cc: sameo@linux.intel.com
> Acked-by: Felipe Balbi <balbi@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> ---
>  drivers/mfd/Kconfig      |    9 ++
>  drivers/mfd/Makefile     |    1 +
>  drivers/mfd/retu-mfd.c   |  264 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/retu.h |   22 ++++
>  4 files changed, 296 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/mfd/retu-mfd.c
>  create mode 100644 include/linux/mfd/retu.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index acab3ef..7528c5e 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1044,6 +1044,15 @@ config MFD_PALMAS
>  	  If you say yes here you get support for the Palmas
>  	  series of PMIC chips from Texas Instruments.
>  
> +config MFD_RETU
> +	tristate "Support for Retu multi-function device"
> +	select MFD_CORE
> +	depends on I2C
> +	select REGMAP_IRQ
> +	help
> +	  Retu is a multi-function device found on Nokia Internet Tablets
> +	  (770, N800 and N810).
> +
>  endmenu
>  endif
>  
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index d8ccb63..ad7879f 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -138,3 +138,4 @@ obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
>  obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
>  obj-$(CONFIG_MFD_SYSCON)	+= syscon.o
>  obj-$(CONFIG_MFD_LM3533)	+= lm3533-core.o lm3533-ctrlbank.o
> +obj-$(CONFIG_MFD_RETU)		+= retu-mfd.o
> diff --git a/drivers/mfd/retu-mfd.c b/drivers/mfd/retu-mfd.c
> new file mode 100644
> index 0000000..7ff4a37
> --- /dev/null
> +++ b/drivers/mfd/retu-mfd.c
> @@ -0,0 +1,264 @@
> +/*
> + * Retu MFD driver
> + *
> + * Copyright (C) 2004, 2005 Nokia Corporation
> + *
> + * Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen.
> + * Rewritten by Aaro Koskinen.
> + *
> + * 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.
> + *
> + * 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/err.h>
> +#include <linux/i2c.h>
> +#include <linux/irq.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/mutex.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/retu.h>
> +#include <linux/interrupt.h>
> +#include <linux/moduleparam.h>
> +
> +/* Registers */
> +#define RETU_REG_ASICR		0x00		/* ASIC ID and revision */
> +#define RETU_REG_ASICR_VILMA	(1 << 7)	/* Bit indicating Vilma */
> +#define RETU_REG_IDR		0x01		/* Interrupt ID */
> +#define RETU_REG_IMR		0x02		/* Interrupt mask */
> +
> +/* Interrupt sources */
> +#define RETU_INT_PWR		0		/* Power button */
> +
> +struct retu_dev {
> +	struct regmap			*regmap;
> +	struct device			*dev;
> +	struct mutex			mutex;
> +	struct regmap_irq_chip_data	*irq_data;
> +};
> +
> +static struct resource retu_pwrbutton_res[] = {
> +	{
> +		.name	= "retu-pwrbutton",
> +		.start	= RETU_INT_PWR,
> +		.end	= RETU_INT_PWR,
> +		.flags	= IORESOURCE_IRQ,
> +	},
> +};
> +
> +static struct mfd_cell retu_devs[] = {
> +	{
> +		.name		= "retu-wdt"
> +	},
> +	{
> +		.name		= "retu-pwrbutton",
> +		.resources	= retu_pwrbutton_res,
> +		.num_resources	= ARRAY_SIZE(retu_pwrbutton_res),
> +	}
> +};
> +
> +static struct regmap_irq retu_irqs[] = {
> +	[RETU_INT_PWR] = {
> +		.mask = 1 << RETU_INT_PWR,
> +	}
> +};
> +
> +static struct regmap_irq_chip retu_irq_chip = {
> +	.name		= "RETU",
> +	.irqs		= retu_irqs,
> +	.num_irqs	= ARRAY_SIZE(retu_irqs),
> +	.num_regs	= 1,
> +	.status_base	= RETU_REG_IDR,
> +	.mask_base	= RETU_REG_IMR,
> +	.ack_base	= RETU_REG_IDR,
> +};
> +
> +/* Retu device registered for the power off. */
> +static struct retu_dev *retu_pm_power_off;
> +
> +int retu_read(struct retu_dev *rdev, u8 reg)
> +{
> +	int ret;
> +	int value;
> +
> +	mutex_lock(&rdev->mutex);
> +	ret = regmap_read(rdev->regmap, reg, &value);
> +	mutex_unlock(&rdev->mutex);
> +
> +	return ret ? ret : value;
> +}
> +EXPORT_SYMBOL_GPL(retu_read);
> +
> +int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
> +{
> +	int ret;
> +
> +	mutex_lock(&rdev->mutex);
> +	ret = regmap_write(rdev->regmap, reg, data);
> +	mutex_unlock(&rdev->mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(retu_write);
> +
> +static void retu_power_off(void)
> +{
> +	struct retu_dev *rdev = retu_pm_power_off;
> +	int reg;
> +
> +	mutex_lock(&retu_pm_power_off->mutex);
> +
> +	/* Ignore power button state */
> +	regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
> +	regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2);
> +
> +	/* Expire watchdog immediately */
> +	regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);
> +
> +	/* Wait for poweroff */
> +	for (;;)
> +		cpu_relax();
> +
> +	mutex_unlock(&retu_pm_power_off->mutex);
> +}
> +
> +static int retu_regmap_read(void *context, const void *reg, size_t reg_size,
> +			    void *val, size_t val_size)
> +{
> +	int ret;
> +	struct device *dev = context;
> +	struct i2c_client *i2c = to_i2c_client(dev);
> +
> +	BUG_ON(reg_size != 1 || val_size != 2);
> +
> +	ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg);
> +	if (ret < 0)
> +		return ret;
> +
> +	*(u16 *)val = ret;
> +	return 0;
> +}
> +
> +static int retu_regmap_write(void *context, const void *data, size_t count)
> +{
> +	u8 reg;
> +	u16 val;
> +	struct device *dev = context;
> +	struct i2c_client *i2c = to_i2c_client(dev);
> +
> +	BUG_ON(count != sizeof(reg) + sizeof(val));
> +	memcpy(&reg, data, sizeof(reg));
> +	memcpy(&val, data + sizeof(reg), sizeof(val));
> +	return i2c_smbus_write_word_data(i2c, reg, val);
> +}
> +
> +static struct regmap_bus retu_bus = {
> +	.read = retu_regmap_read,
> +	.write = retu_regmap_write,
> +	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
> +};
> +
> +static struct regmap_config retu_config = {
> +	.reg_bits = 8,
> +	.val_bits = 16,
> +};
> +
> +static int __devinit retu_probe(struct i2c_client *i2c,
> +				const struct i2c_device_id *id)
> +{
> +	struct retu_dev *rdev;
> +	int ret;
> +
> +	rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
> +	if (rdev == NULL)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(i2c, rdev);
> +	rdev->dev = &i2c->dev;
> +	mutex_init(&rdev->mutex);
> +	rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
> +					&retu_config);
> +	if (IS_ERR(rdev->regmap))
> +		return PTR_ERR(rdev->regmap);
> +
> +	ret = retu_read(rdev, RETU_REG_ASICR);
> +	if (ret < 0) {
> +		dev_err(rdev->dev, "could not read Retu revision: %d\n", ret);
> +		return ret;
> +	}
> +
> +	dev_info(rdev->dev, "Retu%s v%d.%d found\n",
> +		 (ret & RETU_REG_ASICR_VILMA) ? " & Vilma" : "",
> +		 (ret >> 4) & 0x7, ret & 0xf);
> +
> +	/* Mask all RETU interrupts. */
> +	ret = retu_write(rdev, RETU_REG_IMR, 0xffff);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
> +				  &retu_irq_chip, &rdev->irq_data);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = mfd_add_devices(rdev->dev, -1, retu_devs, ARRAY_SIZE(retu_devs),
> +			      NULL, regmap_irq_chip_get_base(rdev->irq_data),
> +			      NULL);
> +	if (ret < 0) {
> +		regmap_del_irq_chip(i2c->irq, rdev->irq_data);
> +		return ret;
> +	}
> +
> +	if (!pm_power_off) {
> +		retu_pm_power_off = rdev;
> +		pm_power_off	  = retu_power_off;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __devexit retu_remove(struct i2c_client *i2c)
> +{
> +	struct retu_dev *rdev = i2c_get_clientdata(i2c);
> +
> +	if (retu_pm_power_off == rdev) {
> +		pm_power_off	  = NULL;
> +		retu_pm_power_off = NULL;
> +	}
> +	mfd_remove_devices(rdev->dev);
> +	regmap_del_irq_chip(i2c->irq, rdev->irq_data);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id retu_id[] = {
> +	{ "retu-mfd", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, retu_id);
> +
> +static struct i2c_driver retu_driver = {
> +	.driver		= {
> +		.name = "retu-mfd",
> +		.owner = THIS_MODULE,
> +	},
> +	.probe		= retu_probe,
> +	.remove		= retu_remove,
> +	.id_table	= retu_id,
> +};
> +module_i2c_driver(retu_driver);
> +
> +MODULE_DESCRIPTION("Retu MFD driver");
> +MODULE_AUTHOR("Juha Yrjölä");
> +MODULE_AUTHOR("David Weinehall");
> +MODULE_AUTHOR("Mikko Ylinen");
> +MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/retu.h b/include/linux/mfd/retu.h
> new file mode 100644
> index 0000000..1e2715d
> --- /dev/null
> +++ b/include/linux/mfd/retu.h
> @@ -0,0 +1,22 @@
> +/*
> + * Retu MFD driver interface
> + *
> + * 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.
> + */
> +
> +#ifndef __LINUX_MFD_RETU_H
> +#define __LINUX_MFD_RETU_H
> +
> +struct retu_dev;
> +
> +int retu_read(struct retu_dev *, u8);
> +int retu_write(struct retu_dev *, u8, u16);
> +
> +/* Registers */
> +#define RETU_REG_WATCHDOG	0x17		/* Watchdog */
> +#define RETU_REG_CC1		0x0d		/* Common control register 1 */
> +#define RETU_REG_STATUS		0x16		/* Status register */
> +
> +#endif /* __LINUX_MFD_RETU_H */
> -- 
> 1.7.2.5
> 
> --
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Re: [RESEND PATCH v3 2/4] mfd: introduce retu-mfd driver

[Tony Lindgren]

* Tony Lindgren <tony@atomide.com> [121120 10:36]:
> * Aaro Koskinen <aaro.koskinen@iki.fi> [121112 11:11]:
> > Retu is a multi-function device found on Nokia Internet Tablets
> > implementing at least watchdog, RTC, headset detection and power button
> > functionality.
> > 
> > This patch implements minimum functionality providing register access,
> > IRQ handling and power off functions.
> 
> Samuel, you can pick this one up separately now that Wolfram has taken
> the i2c-cbus driver.
> 
> Also, just noticed that this probably should depend on I2C_CBUS as this
> chip will not communicate over other I2C adapters?

Sorry meant to reply to "[PATCH v4 2/4] mfd: introduce retu-mfd driver"
instead of this v3 thread.

Regards,

Tony