[RFC PATCH 0/2] MFD and GPIO for STA2X11

[RFC PATCH 0/2] MFD and GPIO for STA2X11

[Alessandro Rubini]

These two patches introduce multi-function device and GPIO support for
the STA2X11 I/O Hub. It's an RFC for both as explained below.

- I think the MFD driver is ok. This MFD_STA2X11 config symbol is
  autoselected by CONFIG_STA2X11, which is pending in the
  "x86: initial support for sta2x11" patch, for which I need to send V2
  later today, with some minor fixes.  Similarly, <asm/sta2x11.h> is
  not upstream yet, so I'll need to resend later, I suppose.

- The GPIO patch has a quirk: I chose to register a single irq chip
  for 128 interrupts but the generic irq_chip only support 32 interrupts.
  I'm sure the hack I did (request the irq descs myself) is not good, but
  what is the best approach here?  Using 4 generic irq chips or defining
  my own, non-generic one?

Thanks a lot
/alessandro

Alessandro Rubini (2):
  mfd: Add driver for STA2X11 MFD block
  gpio: add STA2X11 GPIO block

 drivers/gpio/Kconfig            |    9 +
 drivers/gpio/Makefile           |    1 +
 drivers/gpio/gpio-sta2x11.c     |  380 +++++++++++++++++++++++++++++++
 drivers/mfd/Kconfig             |    6 +
 drivers/mfd/Makefile            |    1 +
 drivers/mfd/sta2x11-mfd.c       |  470 +++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/sta2x11-mfd.h |  186 +++++++++++++++
 7 files changed, 1053 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/gpio-sta2x11.c
 create mode 100644 drivers/mfd/sta2x11-mfd.c
 create mode 100644 include/linux/mfd/sta2x11-mfd.h

-- 
1.7.7.2

[RFC PATCH 1/2] mfd: Add driver for STA2X11 MFD block

[Alessandro Rubini]

This is an RFC as described in the cover letter 0/2

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
---
 drivers/mfd/Kconfig             |    6 +
 drivers/mfd/Makefile            |    1 +
 drivers/mfd/sta2x11-mfd.c       |  470 +++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/sta2x11-mfd.h |  186 +++++++++++++++
 4 files changed, 663 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/sta2x11-mfd.c
 create mode 100644 include/linux/mfd/sta2x11-mfd.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index cd13e9f..36bee4a 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -830,6 +830,12 @@ config MFD_INTEL_MSIC
 	  Passage) chip. This chip embeds audio, battery, GPIO, etc.
 	  devices used in Intel Medfield platforms.
 
+config MFD_STA2X11
+	bool "STA2X11 multi function device support"
+	depends on STA2X11
+	select MFD_CORE
+	select GPIO_STA2X11
+
 endmenu
 endif
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index b953bab..c5db71b 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_MFD_DAVINCI_VOICECODEC)	+= davinci_voicecodec.o
 obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o
 obj-$(CONFIG_MFD_TI_SSP)	+= ti-ssp.o
 
+obj-$(CONFIG_MFD_STA2X11)	+= sta2x11-mfd.o
 obj-$(CONFIG_MFD_STMPE)		+= stmpe.o
 obj-$(CONFIG_STMPE_I2C)		+= stmpe-i2c.o
 obj-$(CONFIG_STMPE_SPI)		+= stmpe-spi.o
diff --git a/drivers/mfd/sta2x11-mfd.c b/drivers/mfd/sta2x11-mfd.c
new file mode 100644
index 0000000..3446f02
--- /dev/null
+++ b/drivers/mfd/sta2x11-mfd.c
@@ -0,0 +1,470 @@
+/*
+ * Copyright (c) 2009-2011 Wind River Systems, Inc.
+ * Copyright (c) 2011 ST Microelectronics (Alessandro Rubini)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/sta2x11-mfd.h>
+
+#include <asm/sta2x11.h>
+
+/* This describes STA2X11 MFD chip for us, we may have several */
+struct sta2x11_mfd {
+	struct sta2x11_instance *instance;
+	spinlock_t lock;
+	struct list_head list;
+	void __iomem *sctl_regs;
+	void __iomem *apbreg_regs;
+};
+
+static LIST_HEAD(sta2x11_mfd_list);
+
+/* Three functions to act on the list */
+static struct sta2x11_mfd *sta2x11_mfd_find(struct pci_dev *pdev)
+{
+	struct sta2x11_instance *instance;
+	struct sta2x11_mfd *mfd;
+
+	if (!pdev && !list_empty(&sta2x11_mfd_list)) {
+		dev_warn(&pdev->dev, "%s: Unspecified device, "
+			    "using first instance\n", __func__);
+		return list_entry(sta2x11_mfd_list.next,
+				  struct sta2x11_mfd, list);
+	}
+
+	instance = sta2x11_get_instance(pdev);
+	if (!instance)
+		return NULL;
+	list_for_each_entry(mfd, &sta2x11_mfd_list, list) {
+		if (mfd->instance == instance)
+			return mfd;
+	}
+	return NULL;
+}
+
+static int __devinit sta2x11_mfd_add(struct pci_dev *pdev, gfp_t flags)
+{
+	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+	struct sta2x11_instance *instance;
+
+	if (mfd)
+		return -EBUSY;
+	instance = sta2x11_get_instance(pdev);
+	if (!instance)
+		return -EINVAL;
+	mfd = kzalloc(sizeof(*mfd), flags);
+	if (!mfd)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&mfd->list);
+	spin_lock_init(&mfd->lock);
+	mfd->instance = instance;
+	list_add(&mfd->list, &sta2x11_mfd_list);
+	return 0;
+}
+
+static int __devexit mfd_remove(struct pci_dev *pdev)
+{
+	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+
+	if (!mfd)
+		return -ENODEV;
+	list_del(&mfd->list);
+	kfree(mfd);
+	return 0;
+}
+
+/* These two functions are exported and are not expected to fail */
+u32 sta2x11_sctl_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val)
+{
+	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+	u32 r;
+	unsigned long flags;
+
+	if (!mfd) {
+		dev_warn(&pdev->dev, ": can't access sctl regs\n");
+		return 0;
+	}
+	if (!mfd->sctl_regs) {
+		dev_warn(&pdev->dev, ": system ctl not initialized\n");
+		return 0;
+	}
+	spin_lock_irqsave(&mfd->lock, flags);
+	r = readl(mfd->sctl_regs + reg);
+	r &= ~mask;
+	r |= val;
+	if (mask)
+		writel(r, mfd->sctl_regs + reg);
+	spin_unlock_irqrestore(&mfd->lock, flags);
+	return r;
+}
+EXPORT_SYMBOL(sta2x11_sctl_mask);
+
+u32 sta2x11_apbreg_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val)
+{
+	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+	u32 r;
+	unsigned long flags;
+
+	if (!mfd) {
+		dev_warn(&pdev->dev, ": can't access apb regs\n");
+		return 0;
+	}
+	if (!mfd->apbreg_regs) {
+		dev_warn(&pdev->dev, ": apb bridge not initialized\n");
+		return 0;
+	}
+	spin_lock_irqsave(&mfd->lock, flags);
+	r = readl(mfd->apbreg_regs + reg);
+	r &= ~mask;
+	r |= val;
+	if (mask)
+		writel(r, mfd->apbreg_regs + reg);
+	spin_unlock_irqrestore(&mfd->lock, flags);
+	return r;
+}
+EXPORT_SYMBOL(sta2x11_apbreg_mask);
+
+/* Two debugfs files, for our registers (FIXME: one instance only) */
+#define REG(regname) {.name = #regname, .offset = SCTL_ ## regname}
+static struct debugfs_reg32 sta2x11_sctl_regs[] = {
+	REG(SCCTL), REG(ARMCFG), REG(SCPLLCTL), REG(SCPLLFCTRL),
+	REG(SCRESFRACT), REG(SCRESCTRL1), REG(SCRESXTRL2), REG(SCPEREN0),
+	REG(SCPEREN1), REG(SCPEREN2), REG(SCGRST), REG(SCPCIPMCR1),
+	REG(SCPCIPMCR2), REG(SCPCIPMSR1), REG(SCPCIPMSR2), REG(SCPCIPMSR3),
+	REG(SCINTREN), REG(SCRISR), REG(SCCLKSTAT0), REG(SCCLKSTAT1),
+	REG(SCCLKSTAT2), REG(SCRSTSTA),
+};
+#undef REG
+
+static struct debugfs_regset32 sctl_regset = {
+	.regs = sta2x11_sctl_regs,
+	.nregs = ARRAY_SIZE(sta2x11_sctl_regs),
+};
+
+#define REG(regname) {.name = #regname, .offset = regname}
+static struct debugfs_reg32 sta2x11_apbreg_regs[] = {
+	REG(APBREG_BSR), REG(APBREG_PAER), REG(APBREG_PWAC), REG(APBREG_PRAC),
+	REG(APBREG_PCG), REG(APBREG_PUR), REG(APBREG_EMU_PCG),
+};
+#undef REG
+
+static struct debugfs_regset32 apbreg_regset = {
+	.regs = sta2x11_apbreg_regs,
+	.nregs = ARRAY_SIZE(sta2x11_apbreg_regs),
+};
+
+static struct dentry *sta2x11_sctl_debugfs;
+static struct dentry *sta2x11_apbreg_debugfs;
+
+/* Probe for the two platform devices */
+static int sta2x11_sctl_probe(struct platform_device *dev)
+{
+	struct pci_dev **pdev;
+	struct sta2x11_mfd *mfd;
+	struct resource *res;
+
+	pdev = dev->dev.platform_data;
+	mfd = sta2x11_mfd_find(*pdev);
+	if (!mfd)
+		return -ENODEV;
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOMEM;
+
+	if (!request_mem_region(res->start, resource_size(res),
+				"sta2x11-sctl"))
+		return -EBUSY;
+
+	mfd->sctl_regs = ioremap(res->start, resource_size(res));
+	if (!mfd->sctl_regs) {
+		release_mem_region(res->start, resource_size(res));
+		return -ENOMEM;
+	}
+	sctl_regset.base = mfd->sctl_regs;
+	sta2x11_sctl_debugfs = debugfs_create_regset32("sta2x11-sctl",
+						  S_IFREG | S_IRUGO,
+						  NULL, &sctl_regset);
+	return 0;
+}
+
+static int sta2x11_apbreg_probe(struct platform_device *dev)
+{
+	struct pci_dev **pdev;
+	struct sta2x11_mfd *mfd;
+	struct resource *res;
+
+	pdev = dev->dev.platform_data;
+	dev_dbg(&dev->dev, "%s: pdata is %p\n", __func__, pdev);
+	dev_dbg(&dev->dev, "%s: *pdata is %p\n", __func__, *pdev);
+
+	mfd = sta2x11_mfd_find(*pdev);
+	if (!mfd)
+		return -ENODEV;
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOMEM;
+
+	if (!request_mem_region(res->start, resource_size(res),
+				"sta2x11-apbreg"))
+		return -EBUSY;
+
+	mfd->apbreg_regs = ioremap(res->start, resource_size(res));
+	if (!mfd->apbreg_regs) {
+		release_mem_region(res->start, resource_size(res));
+		return -ENOMEM;
+	}
+	dev_dbg(&dev->dev, "%s: regbase %p\n", __func__, mfd->apbreg_regs);
+
+	apbreg_regset.base = mfd->apbreg_regs;
+	sta2x11_apbreg_debugfs = debugfs_create_regset32("sta2x11-apbreg",
+						  S_IFREG | S_IRUGO,
+						  NULL, &apbreg_regset);
+	return 0;
+}
+
+/* The two platform drivers */
+static struct platform_driver sta2x11_sctl_platform_driver = {
+	.driver = {
+		.name	= "sta2x11-sctl",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= sta2x11_sctl_probe,
+};
+
+static int __init sta2x11_sctl_init(void)
+{
+	pr_info("%s\n", __func__);
+	return platform_driver_register(&sta2x11_sctl_platform_driver);
+}
+
+static struct platform_driver sta2x11_platform_driver = {
+	.driver = {
+		.name	= "sta2x11-apbreg",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= sta2x11_apbreg_probe,
+};
+
+static int __init sta2x11_apbreg_init(void)
+{
+	pr_info("%s\n", __func__);
+	return platform_driver_register(&sta2x11_platform_driver);
+}
+
+/*
+ * What follows is the PCI device that hosts the above two pdevs.
+ * Each logic block is 4kB and they are all consecutive: we use this info.
+ */
+
+/* Bar 0 */
+enum bar0_cells {
+	GPIO_0 = 0,
+	GPIO_1,
+	GPIO_2,
+	GPIO_3,
+	SCTL,
+	SCR,
+	TIME,
+};
+/* Bar 1 */
+enum bar1_cells {
+	APBREG = 0,
+};
+#define CELL_4K(_name, _cell) { \
+		.name = _name, \
+		.start = _cell * 4096, .end = _cell * 4096 + 4095, \
+		.flags = IORESOURCE_MEM, \
+		}
+
+static const __devinitconst struct resource gpio_resources[] = {
+	{
+		.name = "sta2x11_gpio", /* 4 consecutive cells, 1 driver */
+		.start = 0,
+		.end = (4 * 4096) - 1,
+		.flags = IORESOURCE_MEM,
+	}
+};
+static const __devinitconst struct resource sctl_resources[] = {
+	CELL_4K("sta2x11-sctl", SCTL),
+};
+static const __devinitconst struct resource scr_resources[] = {
+	CELL_4K("sta2x11-scr", SCR),
+};
+static const __devinitconst struct resource time_resources[] = {
+	CELL_4K("sta2x11-time", TIME),
+};
+
+static const __devinitconst struct resource apbreg_resources[] = {
+	CELL_4K("sta2x11-apbreg", APBREG),
+};
+
+#define DEV(_name, _r) \
+	{ .name = _name, .num_resources = ARRAY_SIZE(_r), .resources = _r, }
+
+static __devinitdata struct mfd_cell sta2x11_mfd_bar0[] = {
+	DEV("sta2x11-gpio", gpio_resources), /* offset 0: we add pdata later */
+	DEV("sta2x11-sctl", sctl_resources),
+	DEV("sta2x11-scr", scr_resources),
+	DEV("sta2x11-time", time_resources),
+};
+
+static __devinitdata struct mfd_cell sta2x11_mfd_bar1[] = {
+	DEV("sta2x11-apbreg", apbreg_resources),
+};
+
+static int sta2x11_mfd_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	pci_save_state(pdev);
+	pci_disable_device(pdev);
+	pci_set_power_state(pdev, pci_choose_state(pdev, state));
+
+	return 0;
+}
+
+static int sta2x11_mfd_resume(struct pci_dev *pdev)
+{
+	int err;
+
+	pci_set_power_state(pdev, 0);
+	err = pci_enable_device(pdev);
+	if (err)
+		return err;
+	pci_restore_state(pdev);
+
+	return 0;
+}
+
+static int __devinit sta2x11_mfd_probe(struct pci_dev *pdev,
+				       const struct pci_device_id *pci_id)
+{
+	int err, i;
+	struct sta2x11_gpio_pdata *gpio_data;
+
+	dev_info(&pdev->dev, "%s\n", __func__);
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Can't enable device.\n");
+		return err;
+	}
+
+	err = pci_enable_msi(pdev);
+	if (err)
+		dev_info(&pdev->dev, "Enable msi failed\n");
+
+	/* Read gpio config data as pci device's platform data */
+	gpio_data = dev_get_platdata(&pdev->dev);
+	if (!gpio_data)
+		dev_warn(&pdev->dev, "no gpio configuration\n");
+
+#if 1
+	dev_dbg(&pdev->dev, "%s, gpio_data = %p (%p)\n", __func__,
+		gpio_data, &gpio_data);
+#endif
+	dev_dbg(&pdev->dev, "%s, pdev = %p (%p)\n", __func__,
+		pdev, &pdev);
+
+
+	/* platform data is the pci device for all of them */
+	for (i = 0; i < ARRAY_SIZE(sta2x11_mfd_bar0); i++) {
+		sta2x11_mfd_bar0[i].pdata_size = sizeof(pdev);
+		sta2x11_mfd_bar0[i].platform_data = &pdev;
+	}
+	sta2x11_mfd_bar1[0].pdata_size = sizeof(pdev);
+	sta2x11_mfd_bar1[0].platform_data = &pdev;
+
+	/* Record this pdev before mfd_add_devices: their probe looks for it */
+	sta2x11_mfd_add(pdev, GFP_ATOMIC);
+
+
+	err = mfd_add_devices(&pdev->dev, -1,
+			      sta2x11_mfd_bar0,
+			      ARRAY_SIZE(sta2x11_mfd_bar0),
+			      &pdev->resource[0],
+			      0);
+	if (err) {
+		dev_err(&pdev->dev, "mfd_add_devices[0] failed: %d\n", err);
+		goto err_disable;
+	}
+
+	err = mfd_add_devices(&pdev->dev, -1,
+			      sta2x11_mfd_bar1,
+			      ARRAY_SIZE(sta2x11_mfd_bar1),
+			      &pdev->resource[1],
+			      0);
+	if (err) {
+		dev_err(&pdev->dev, "mfd_add_devices[1] failed: %d\n", err);
+		goto err_disable;
+	}
+
+	return 0;
+
+err_disable:
+	pci_disable_device(pdev);
+	pci_disable_msi(pdev);
+	/* mfd_remove(pdev); -- it is in an exit section, I can't call it */
+	return err;
+}
+
+static DEFINE_PCI_DEVICE_TABLE(sta2x11_mfd_tbl) = {
+	{PCI_DEVICE(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_GPIO)},
+	{0,},
+};
+
+static struct pci_driver sta2x11_mfd_driver = {
+	.name =		"sta2x11-mfd",
+	.id_table =	sta2x11_mfd_tbl,
+	.probe =	sta2x11_mfd_probe,
+	.suspend =	sta2x11_mfd_suspend,
+	.resume =	sta2x11_mfd_resume,
+};
+
+static int __init sta2x11_mfd_init(void)
+{
+	pr_info("%s\n", __func__);
+	return pci_register_driver(&sta2x11_mfd_driver);
+}
+
+/*
+ * All of this must be ready before "normal" devices like MMCI appear.
+ * But MFD (the pci device) can't be too early. The following choice
+ * prepares platform drivers very early and probe the PCI device later,
+ * but before other PCI devices.
+ */
+subsys_initcall(sta2x11_apbreg_init);
+subsys_initcall(sta2x11_sctl_init);
+rootfs_initcall(sta2x11_mfd_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wind River");
+MODULE_DESCRIPTION("STA2x11 mfd for GPIO, SCTL and APBREG");
+MODULE_DEVICE_TABLE(pci, sta2x11_mfd_tbl);
diff --git a/include/linux/mfd/sta2x11-mfd.h b/include/linux/mfd/sta2x11-mfd.h
new file mode 100644
index 0000000..b53af98
--- /dev/null
+++ b/include/linux/mfd/sta2x11-mfd.h
@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2009-2011 Wind River Systems, Inc.
+ * Copyright (c) 2011 ST Microelectronics (Alessandro Rubini)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * The STMicroelectronics ConneXt (STA2X11) chip has several unrelated
+ * functions in one PCI endpoint functions. This driver simply
+ * registers the platform devices in this iomemregion and exports a few
+ * functions to access common registers
+ */
+
+#ifndef __STA2X11_MFD_H
+#define __STA2X11_MFD_H
+#include <linux/types.h>
+
+/*
+ * The MFD PCI block includes the GPIO peripherals and other register blocks.
+ * For GPIO, we have 32*4 bits (I use "gsta" for "gpio sta2x11".)
+ */
+#define GSTA_GPIO_PER_BLOCK	32
+#define GSTA_NR_BLOCKS		4
+#define GSTA_NR_GPIO		(GSTA_GPIO_PER_BLOCK * GSTA_NR_BLOCKS)
+
+/* Pinconfig is set by the board definition: altfunc, pull-up, pull-down */
+struct sta2x11_gpio_pdata {
+	unsigned pinconfig[GSTA_NR_GPIO];
+};
+
+/*
+ * The APB bridge has its own registers, needed by our users as well.
+ * They are accessed with the following read/mask/write function.
+ */
+u32 sta2x11_apbreg_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val);
+
+
+
+/* CAN and MLB */
+#define APBREG_BSR	0x00	/* Bridge Status Reg */
+#define APBREG_PAER	0x08	/* Peripherals Address Error Reg */
+#define APBREG_PWAC	0x20	/* Peripheral Write Access Control reg */
+#define APBREG_PRAC	0x40	/* Peripheral Read Access Control reg */
+#define APBREG_PCG	0x60	/* Peripheral Clock Gating Reg */
+#define APBREG_PUR	0x80	/* Peripheral Under Reset Reg */
+#define APBREG_EMU_PCG	0xA0	/* Emulator Peripheral Clock Gating Reg */
+
+#define APBREG_CAN	(1 << 1)
+#define APBREG_MLB	(1 << 3)
+
+/* SARAC */
+#define APBREG_BSR_SARAC     0x100 /* Bridge Status Reg */
+#define APBREG_PAER_SARAC    0x108 /* Peripherals Address Error Reg */
+#define APBREG_PWAC_SARAC    0x120 /* Peripheral Write Access Control reg */
+#define APBREG_PRAC_SARAC    0x140 /* Peripheral Read Access Control reg */
+#define APBREG_PCG_SARAC     0x160 /* Peripheral Clock Gating Reg */
+#define APBREG_PUR_SARAC     0x180 /* Peripheral Under Reset Reg */
+#define APBREG_EMU_PCG_SARAC 0x1A0 /* Emulator Peripheral Clock Gating Reg */
+
+#define APBREG_SARAC	(1 << 2)
+
+/*
+ * The system controller has its own registers. Some of these are accessed
+ * by out users as well, using the following read/mask/write/function
+ */
+u32 sta2x11_sctl_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val);
+
+#define SCTL_SCCTL		0x00	/* System controller control register */
+#define SCTL_ARMCFG		0x04	/* ARM configuration register */
+#define SCTL_SCPLLCTL		0x08	/* PLL control status register */
+#define SCTL_SCPLLFCTRL		0x0c	/* PLL frequency control register */
+#define SCTL_SCRESFRACT		0x10	/* PLL fractional input register */
+#define SCTL_SCRESCTRL1		0x14	/* Peripheral reset control 1 */
+#define SCTL_SCRESXTRL2		0x18	/* Peripheral reset control 2 */
+#define SCTL_SCPEREN0		0x1c	/* Peripheral clock enable register 0 */
+#define SCTL_SCPEREN1		0x20	/* Peripheral clock enable register 1 */
+#define SCTL_SCPEREN2		0x24	/* Peripheral clock enable register 2 */
+#define SCTL_SCGRST		0x28	/* Peripheral global reset */
+#define SCTL_SCPCIPMCR1		0x30	/* PCI power management control 1 */
+#define SCTL_SCPCIPMCR2		0x34	/* PCI power management control 2 */
+#define SCTL_SCPCIPMSR1		0x38	/* PCI power management status 1 */
+#define SCTL_SCPCIPMSR2		0x3c	/* PCI power management status 2 */
+#define SCTL_SCPCIPMSR3		0x40	/* PCI power management status 3 */
+#define SCTL_SCINTREN		0x44	/* Interrupt enable */
+#define SCTL_SCRISR		0x48	/* RAW interrupt status */
+#define SCTL_SCCLKSTAT0		0x4c	/* Peripheral clocks status 0 */
+#define SCTL_SCCLKSTAT1		0x50	/* Peripheral clocks status 1 */
+#define SCTL_SCCLKSTAT2		0x54	/* Peripheral clocks status 2 */
+#define SCTL_SCRSTSTA		0x58	/* Reset status register */
+
+#define SCTL_SCRESCTRL1_USB_PHY_POR	(1 << 0)
+#define SCTL_SCRESCTRL1_USB_OTG	(1 << 1)
+#define SCTL_SCRESCTRL1_USB_HRST	(1 << 2)
+#define SCTL_SCRESCTRL1_USB_PHY_HOST	(1 << 3)
+#define SCTL_SCRESCTRL1_SATAII	(1 << 4)
+#define SCTL_SCRESCTRL1_VIP		(1 << 5)
+#define SCTL_SCRESCTRL1_PER_MMC0	(1 << 6)
+#define SCTL_SCRESCTRL1_PER_MMC1	(1 << 7)
+#define SCTL_SCRESCTRL1_PER_GPIO0	(1 << 8)
+#define SCTL_SCRESCTRL1_PER_GPIO1	(1 << 9)
+#define SCTL_SCRESCTRL1_PER_GPIO2	(1 << 10)
+#define SCTL_SCRESCTRL1_PER_GPIO3	(1 << 11)
+#define SCTL_SCRESCTRL1_PER_MTU0	(1 << 12)
+#define SCTL_SCRESCTRL1_KER_SPI0	(1 << 13)
+#define SCTL_SCRESCTRL1_KER_SPI1	(1 << 14)
+#define SCTL_SCRESCTRL1_KER_SPI2	(1 << 15)
+#define SCTL_SCRESCTRL1_KER_MCI0	(1 << 16)
+#define SCTL_SCRESCTRL1_KER_MCI1	(1 << 17)
+#define SCTL_SCRESCTRL1_PRE_HSI2C0	(1 << 18)
+#define SCTL_SCRESCTRL1_PER_HSI2C1	(1 << 19)
+#define SCTL_SCRESCTRL1_PER_HSI2C2	(1 << 20)
+#define SCTL_SCRESCTRL1_PER_HSI2C3	(1 << 21)
+#define SCTL_SCRESCTRL1_PER_MSP0	(1 << 22)
+#define SCTL_SCRESCTRL1_PER_MSP1	(1 << 23)
+#define SCTL_SCRESCTRL1_PER_MSP2	(1 << 24)
+#define SCTL_SCRESCTRL1_PER_MSP3	(1 << 25)
+#define SCTL_SCRESCTRL1_PER_MSP4	(1 << 26)
+#define SCTL_SCRESCTRL1_PER_MSP5	(1 << 27)
+#define SCTL_SCRESCTRL1_PER_MMC	(1 << 28)
+#define SCTL_SCRESCTRL1_KER_MSP0	(1 << 29)
+#define SCTL_SCRESCTRL1_KER_MSP1	(1 << 30)
+#define SCTL_SCRESCTRL1_KER_MSP2	(1 << 31)
+
+#define SCTL_SCPEREN0_UART0		(1 << 0)
+#define SCTL_SCPEREN0_UART1		(1 << 1)
+#define SCTL_SCPEREN0_UART2		(1 << 2)
+#define SCTL_SCPEREN0_UART3		(1 << 3)
+#define SCTL_SCPEREN0_MSP0		(1 << 4)
+#define SCTL_SCPEREN0_MSP1		(1 << 5)
+#define SCTL_SCPEREN0_MSP2		(1 << 6)
+#define SCTL_SCPEREN0_MSP3		(1 << 7)
+#define SCTL_SCPEREN0_MSP4		(1 << 8)
+#define SCTL_SCPEREN0_MSP5		(1 << 9)
+#define SCTL_SCPEREN0_SPI0		(1 << 10)
+#define SCTL_SCPEREN0_SPI1		(1 << 11)
+#define SCTL_SCPEREN0_SPI2		(1 << 12)
+#define SCTL_SCPEREN0_I2C0		(1 << 13)
+#define SCTL_SCPEREN0_I2C1		(1 << 14)
+#define SCTL_SCPEREN0_I2C2		(1 << 15)
+#define SCTL_SCPEREN0_I2C3		(1 << 16)
+#define SCTL_SCPEREN0_SVDO_LVDS		(1 << 17)
+#define SCTL_SCPEREN0_USB_HOST		(1 << 18)
+#define SCTL_SCPEREN0_USB_OTG		(1 << 19)
+#define SCTL_SCPEREN0_MCI0		(1 << 20)
+#define SCTL_SCPEREN0_MCI1		(1 << 21)
+#define SCTL_SCPEREN0_MCI2		(1 << 22)
+#define SCTL_SCPEREN0_MCI3		(1 << 23)
+#define SCTL_SCPEREN0_SATA		(1 << 24)
+#define SCTL_SCPEREN0_ETHERNET		(1 << 25)
+#define SCTL_SCPEREN0_VIC		(1 << 26)
+#define SCTL_SCPEREN0_DMA_AUDIO		(1 << 27)
+#define SCTL_SCPEREN0_DMA_SOC		(1 << 28)
+#define SCTL_SCPEREN0_RAM		(1 << 29)
+#define SCTL_SCPEREN0_VIP		(1 << 30)
+#define SCTL_SCPEREN0_ARM		(1 << 31)
+
+#define SCTL_SCPEREN1_UART0		(1 << 0)
+#define SCTL_SCPEREN1_UART1		(1 << 1)
+#define SCTL_SCPEREN1_UART2		(1 << 2)
+#define SCTL_SCPEREN1_UART3		(1 << 3)
+#define SCTL_SCPEREN1_MSP0		(1 << 4)
+#define SCTL_SCPEREN1_MSP1		(1 << 5)
+#define SCTL_SCPEREN1_MSP2		(1 << 6)
+#define SCTL_SCPEREN1_MSP3		(1 << 7)
+#define SCTL_SCPEREN1_MSP4		(1 << 8)
+#define SCTL_SCPEREN1_MSP5		(1 << 9)
+#define SCTL_SCPEREN1_SPI0		(1 << 10)
+#define SCTL_SCPEREN1_SPI1		(1 << 11)
+#define SCTL_SCPEREN1_SPI2		(1 << 12)
+#define SCTL_SCPEREN1_I2C0		(1 << 13)
+#define SCTL_SCPEREN1_I2C1		(1 << 14)
+#define SCTL_SCPEREN1_I2C2		(1 << 15)
+#define SCTL_SCPEREN1_I2C3		(1 << 16)
+#define SCTL_SCPEREN1_USB_PHY		(1 << 17)
+
+#endif /* __STA2X11_MFD_H */
-- 
1.7.7.2

[RFC PATCH 2/2] gpio: add STA2X11 GPIO block

[Alessandro Rubini]

This introduces 128 gpio bits (for each device) and with interrupt support.
It is tested and working, but it's still an RFC.

It still misses the alternate-function and pull-up/pull-down support.
I don't know if it should be a different patch or merged in this the
next time I submit.

Moreover, this is an RFC as described in the cover letter 0/2

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
---
 drivers/gpio/Kconfig        |    9 +
 drivers/gpio/Makefile       |    1 +
 drivers/gpio/gpio-sta2x11.c |  380 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 390 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/gpio-sta2x11.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d0c4118..fab6ca7 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -149,6 +149,14 @@ config GPIO_PXA
 	help
 	  Say yes here to support the PXA GPIO device
 
+config GPIO_STA2X11
+	bool "STA2x11/ConneXt GPIO support"
+	depends on MFD_STA2X11
+	select GENERIC_IRQ_CHIP
+	help
+	  Say yes here to support the STA2x11/ConneXt GPIO device.
+	  The GPIO module has 128 GPIO pins with alternate functions.
+
 config GPIO_XILINX
 	bool "Xilinx GPIO support"
 	depends on PPC_OF || MICROBLAZE
@@ -489,4 +497,5 @@ config GPIO_TPS65910
 	help
 	  Select this option to enable GPIO driver for the TPS65910
 	  chip family.
+
 endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index fa10df6..81a28cf 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_GPIO_RDC321X)	+= gpio-rdc321x.o
 obj-$(CONFIG_PLAT_SAMSUNG)	+= gpio-samsung.o
 obj-$(CONFIG_ARCH_SA1100)	+= gpio-sa1100.o
 obj-$(CONFIG_GPIO_SCH)		+= gpio-sch.o
+obj-$(CONFIG_GPIO_STA2X11)	+= gpio-sta2x11.o
 obj-$(CONFIG_GPIO_STMPE)	+= gpio-stmpe.o
 obj-$(CONFIG_GPIO_SX150X)	+= gpio-sx150x.o
 obj-$(CONFIG_GPIO_TC3589X)	+= gpio-tc3589x.o
diff --git a/drivers/gpio/gpio-sta2x11.c b/drivers/gpio/gpio-sta2x11.c
new file mode 100644
index 0000000..377dcb1
--- /dev/null
+++ b/drivers/gpio/gpio-sta2x11.c
@@ -0,0 +1,380 @@
+/*
+ * STMicroelectronics ConneXt (STA2X11) GPIO driver
+ *
+ * Copyright 2012 ST Microelectronics (Alessandro Rubini)
+ * Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd.
+ * Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/sta2x11-mfd.h>
+
+struct gsta_regs {
+	u32 dat;		/* 0x00 */
+	u32 dats;
+	u32 datc;
+	u32 pdis;
+	u32 dir;		/* 0x10 */
+	u32 dirs;
+	u32 dirc;
+	u32 unused_1c;
+	u32 afsela;		/* 0x20 */
+	u32 unused_24[7];
+	u32 rimsc;		/* 0x40 */
+	u32 fimsc;
+	u32 is;
+	u32 ic;
+};
+
+struct gsta_gpio {
+	spinlock_t		lock;
+	struct device		*dev;
+	void __iomem		*reg_base;
+	struct gsta_regs	*regs[GSTA_NR_BLOCKS];
+	struct gpio_chip	gpio;
+	int			irq_base;
+	/* FIXME: save the whole config here (AF, ...) */
+	unsigned		irq_type[GSTA_NR_GPIO];
+};
+
+static inline struct gsta_regs __iomem *__regs(struct gsta_gpio *chip, int nr)
+{
+	return chip->regs[nr / GSTA_GPIO_PER_BLOCK];
+}
+
+static inline u32 __bit(int nr)
+{
+	return 1U << (nr % GSTA_GPIO_PER_BLOCK);
+}
+
+/*
+ * gpio methods
+ */
+
+static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
+{
+	struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+	struct gsta_regs __iomem *regs = __regs(chip, nr);
+	u32 bit = __bit(nr);
+
+	if (val)
+		writel(bit, &regs->dats);
+	else
+		writel(bit, &regs->datc);
+}
+
+static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr)
+{
+	struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+	struct gsta_regs __iomem *regs = __regs(chip, nr);
+	u32 bit = __bit(nr);
+
+	return readl(&regs->dat) & bit;
+}
+
+static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
+				      int val)
+{
+	struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+	struct gsta_regs __iomem *regs = __regs(chip, nr);
+	u32 bit = __bit(nr);
+
+	writel(bit, &regs->dirs);
+	/* Data register after direction, otherwise pullup/down is selected */
+	if (val)
+		writel(bit, &regs->dats);
+	else
+		writel(bit, &regs->datc);
+	return 0;
+}
+
+static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
+{
+	struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+	struct gsta_regs __iomem *regs = __regs(chip, nr);
+	u32 bit = __bit(nr);
+
+	writel(bit, &regs->dirc);
+	return 0;
+}
+
+static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
+{
+	struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+	return chip->irq_base + offset;
+}
+
+static void gsta_gpio_setup(struct gsta_gpio *chip) /* called from probe */
+{
+	struct gpio_chip *gpio = &chip->gpio;
+
+	/*
+	 * ARCH_NR_GPIOS is currently 256 and dynamic allocation starts
+	 * from the end. However, for compatiility, we need the first
+	 * ConneXt device to start from gpio 0, because it's the main
+	 * chipset on most boards both documents and drivers assume that.
+	 */
+	static int gpio_base;
+
+	gpio->label = dev_name(chip->dev);
+	gpio->owner = THIS_MODULE;
+	gpio->direction_input = gsta_gpio_direction_input;
+	gpio->get = gsta_gpio_get;
+	gpio->direction_output = gsta_gpio_direction_output;
+	gpio->set = gsta_gpio_set;
+	gpio->dbg_show = NULL;
+	gpio->base = gpio_base;
+	gpio->base = 0;
+	gpio->ngpio = GSTA_NR_GPIO;
+	gpio->can_sleep = 0;
+	gpio->to_irq = gsta_gpio_to_irq;
+
+
+	/*
+	 * After the first device, turn to dynamic gpio numbers.
+	 * With ARCH_NR_GPIOS = 256 we can fit for example two steval cards
+	 */
+	if (!gpio_base)
+		gpio_base = 1;
+}
+
+/*
+ * Special methods: alternate functins and pullup/pulldown
+ */
+
+/* FIXME */
+
+/*
+ * Irq methods
+ */
+
+static void gsta_irq_disable(struct irq_data *data)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+	struct gsta_gpio *chip = gc->private;
+	int nr = data->irq - chip->irq_base;
+	struct gsta_regs __iomem *regs = __regs(chip, nr);
+	u32 bit = __bit(nr);
+	u32 val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) {
+		val = readl(&regs->rimsc) & ~bit;
+		writel(val, &regs->rimsc);
+	}
+	if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) {
+		val = readl(&regs->fimsc) & ~bit;
+		writel(val, &regs->fimsc);
+	}
+	return;
+}
+
+static void gsta_irq_enable(struct irq_data *data)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+	struct gsta_gpio *chip = gc->private;
+	int nr = data->irq - chip->irq_base;
+	struct gsta_regs __iomem *regs = __regs(chip, nr);
+	u32 bit = __bit(nr);
+	u32 val;
+	int type;
+	unsigned long flags;
+
+	type = chip->irq_type[nr];
+
+	spin_lock_irqsave(&chip->lock, flags);
+	val = readl(&regs->rimsc);
+	if (type & IRQ_TYPE_EDGE_RISING)
+		writel(val | bit, &regs->rimsc);
+	else
+		writel(val & ~bit, &regs->rimsc);
+	val = readl(&regs->rimsc);
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		writel(val | bit, &regs->fimsc);
+	else
+		writel(val & ~bit, &regs->fimsc);
+	spin_unlock_irqrestore(&chip->lock, flags);
+	return;
+}
+
+static int gsta_irq_type(struct irq_data *d, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct gsta_gpio *chip = gc->private;
+	int nr = d->irq - chip->irq_base;
+
+	/* We only support edge interrupts */
+	if (!(type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))) {
+		pr_debug("%s: unsupported type 0x%x\n", __func__, type);
+		return -EINVAL;
+	}
+
+	chip->irq_type[nr] = type; /* used for enable/disable */
+
+	gsta_irq_enable(d);
+	return 0;
+}
+
+static irqreturn_t gsta_gpio_handler(int irq, void *dev_id)
+{
+	struct gsta_gpio *chip = dev_id;
+	struct gsta_regs __iomem *regs;
+	u32 is;
+	int i, nr, base;
+	irqreturn_t ret = IRQ_NONE;
+
+	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
+		regs = chip->regs[i];
+		base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK;
+		while ((is = readl(&regs->is))) {
+			nr = __ffs(is);
+			irq = base + nr;
+			generic_handle_irq(irq);
+			writel(1 << nr, &regs->ic);
+			ret = IRQ_HANDLED;
+		}
+	}
+	return ret;
+}
+
+static __devinit void gsta_alloc_irq_chip(struct gsta_gpio *chip)
+{
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+
+	gc = irq_alloc_generic_chip(KBUILD_MODNAME, 1, chip->irq_base,
+				     chip->reg_base, handle_simple_irq);
+	gc->private = chip;
+	ct = gc->chip_types;
+
+	ct->chip.irq_set_type = gsta_irq_type;
+	ct->chip.irq_disable = gsta_irq_disable;
+	ct->chip.irq_enable = gsta_irq_enable;
+
+	/* FIXME: this makes at most 32 interrupts. Request 0 by now */
+	irq_setup_generic_chip(gc, 0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */, 0,
+			       IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+
+	/* Set up all all 128 interrupts: code from setup_generic_chip */
+	{
+		struct irq_chip_type *ct = gc->chip_types;
+		int i, j;
+		for (j = 0; j < GSTA_NR_GPIO; j++) {
+			i = chip->irq_base + j;
+			irq_set_chip_and_handler(i, &ct->chip, ct->handler);
+			irq_set_chip_data(i, gc);
+			irq_modify_status(i, IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+		}
+		gc->irq_cnt = i - gc->irq_base;
+	}
+}
+
+/* The platform device used here is instantiated by the MFD device */
+static int __devinit gsta_probe(struct platform_device *dev)
+{
+	int i, err;
+	struct pci_dev *pdev;
+	struct sta2x11_gpio_pdata *gpio_data;
+	struct gsta_gpio *chip;
+	struct resource *res;
+
+	pdev = *(struct pci_dev **)(dev->dev.platform_data);
+	gpio_data = dev_get_platdata(&pdev->dev);
+
+	if (gpio_data == NULL)
+		dev_err(&dev->dev, "%s, NULL gpio config\n", __func__);
+	/* FIXME: use gpio_data */
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	request_mem_region(res->start, resource_size(res), KBUILD_MODNAME);
+
+
+	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+	chip->dev = &dev->dev;
+	chip->reg_base = ioremap(res->start, resource_size(res));
+	chip->irq_base = -1;
+	spin_lock_init(&chip->lock);
+	gsta_gpio_setup(chip);
+	err = gpiochip_add(&chip->gpio);
+	if (err < 0) {
+		dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n",
+			-err);
+		kfree(chip);
+		return err;
+	}
+	/* 384 was used in previous code: be compatible for other drivers */
+	err = irq_alloc_descs(-1, 384, GSTA_NR_GPIO, NUMA_NO_NODE);
+
+	if (err < 0) {
+		dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
+			 -err);
+		goto err_out;
+	}
+	chip->irq_base = err;
+	gsta_alloc_irq_chip(chip);
+
+	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
+		chip->regs[i] = chip->reg_base + i * 4096;
+		/* disable all irqs */
+		writel(0, &chip->regs[i]->rimsc);
+		writel(0, &chip->regs[i]->fimsc);
+		writel(~0, &chip->regs[i]->ic);
+	}
+
+	err = request_irq(pdev->irq, gsta_gpio_handler,
+			     IRQF_SHARED, KBUILD_MODNAME, chip);
+	if (err < 0) {
+		dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n",
+			-err);
+		goto err_out;
+	}
+
+	platform_set_drvdata(dev, chip);
+	return 0;
+
+err_out:
+	if (chip->irq_base > 0)
+		irq_free_descs(chip->irq_base, GSTA_NR_GPIO);
+	kfree(chip);
+	return err;
+}
+
+static struct platform_driver sta2x11_gpio_platform_driver = {
+	.driver = {
+		.name	= "sta2x11-gpio",
+		.owner	= THIS_MODULE,
+	},
+	.probe = gsta_probe,
+};
+
+static int __init sta2x11_gpio_init(void)
+{
+	return platform_driver_register(&sta2x11_gpio_platform_driver);
+}
+
+module_init(sta2x11_gpio_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("sta2x11_gpio GPIO driver");
-- 
1.7.7.2