gpio: Add PMIC GPIO block support

Moorestown has PMIC chip which contains GPIO blocks. The PMIC chip is
connected to Langwell by SPI interface. So this GPIO driver will be regarded
as SPI GPIO expander though the actual GPIO access is through IPC and SRAM.
The SPI master contoller will probe this device driver by parsing SPIB table.

Cleaned up for new IPC, GPE removed and some printk and other tidying by
Alan Cox. Fixes for points noted by Matthew Garrett
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/Kconfig

@@ -540,6 +540,13 @@ config INTEL_SCU_IPC
 	  some embedded Intel x86 platforms. This is not needed for PC-type
 	  machines.
 
+config GPIO_INTEL_PMIC
+	bool "Intel PMIC GPIO support"
+	depends on INTEL_SCU_IPC && GPIOLIB
+	---help---
+	  Say Y here to support GPIO via the SCU IPC interface
+	  on Intel MID platforms.
+
 config RAR_REGISTER
 	bool "Restricted Access Region Register Driver"
 	depends on PCI && X86_MRST

drivers/platform/x86/Makefile

@@ -28,3 +28,5 @@ obj-$(CONFIG_TOSHIBA_BT_RFKILL)	+= toshiba_bluetooth.o
 obj-$(CONFIG_INTEL_SCU_IPC)	+= intel_scu_ipc.o
 obj-$(CONFIG_RAR_REGISTER)	+= intel_rar_register.o
 obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
+obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
+

drivers/platform/x86/intel_pmic_gpio.c

+/* Moorestown PMIC GPIO (access through IPC) driver
+ * Copyright (c) 2008 - 2009, Intel Corporation.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* Supports:
+ * Moorestown platform PMIC chip
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/stddef.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <asm/intel_scu_ipc.h>
+#include <linux/device.h>
+#include <linux/intel_pmic_gpio.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME "pmic_gpio"
+
+/* register offset that IPC driver should use
+ * 8 GPIO + 8 GPOSW (6 controllable) + 8GPO
+ */
+enum pmic_gpio_register {
+	GPIO0		= 0xE0,
+	GPIO7		= 0xE7,
+	GPIOINT		= 0xE8,
+	GPOSWCTL0	= 0xEC,
+	GPOSWCTL5	= 0xF1,
+	GPO		= 0xF4,
+};
+
+/* bits definition for GPIO & GPOSW */
+#define GPIO_DRV 0x01
+#define GPIO_DIR 0x02
+#define GPIO_DIN 0x04
+#define GPIO_DOU 0x08
+#define GPIO_INTCTL 0x30
+#define GPIO_DBC 0xc0
+
+#define GPOSW_DRV 0x01
+#define GPOSW_DOU 0x08
+#define GPOSW_RDRV 0x30
+
+
+#define NUM_GPIO 24
+
+struct pmic_gpio_irq {
+	spinlock_t lock;
+	u32 trigger[NUM_GPIO];
+	u32 dirty;
+	struct work_struct work;
+};
+
+
+struct pmic_gpio {
+	struct gpio_chip	chip;
+	struct pmic_gpio_irq	irqtypes;
+	void			*gpiointr;
+	int			irq;
+	unsigned		irq_base;
+};
+
+static void pmic_program_irqtype(int gpio, int type)
+{
+	if (type & IRQ_TYPE_EDGE_RISING)
+		intel_scu_ipc_update_register(GPIO0 + gpio, 0x20, 0x20);
+	else
+		intel_scu_ipc_update_register(GPIO0 + gpio, 0x00, 0x20);
+
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		intel_scu_ipc_update_register(GPIO0 + gpio, 0x10, 0x10);
+	else
+		intel_scu_ipc_update_register(GPIO0 + gpio, 0x00, 0x10);
+};
+
+static void pmic_irqtype_work(struct work_struct *work)
+{
+	struct pmic_gpio_irq *t =
+		container_of(work, struct pmic_gpio_irq, work);
+	unsigned long flags;
+	int i;
+	u16 type;
+
+	spin_lock_irqsave(&t->lock, flags);
+	/* As we drop the lock, we may need multiple scans if we race the
+	   pmic_irq_type function */
+	while (t->dirty) {
+		/*
+		 *	For each pin that has the dirty bit set send an IPC
+		 *	message to configure the hardware via the PMIC
+		 */
+		for (i = 0; i < NUM_GPIO; i++) {
+			if (!(t->dirty & (1 << i)))
+				continue;
+			t->dirty &= ~(1 << i);
+			/* We can't trust the array entry or dirty
+			   once the lock is dropped */
+			type = t->trigger[i];
+			spin_unlock_irqrestore(&t->lock, flags);
+			pmic_program_irqtype(i, type);
+			spin_lock_irqsave(&t->lock, flags);
+		}
+	}
+	spin_unlock_irqrestore(&t->lock, flags);
+}
+
+static int pmic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	if (offset > 8) {
+		printk(KERN_ERR
+			"%s: only pin 0-7 support input\n", __func__);
+		return -1;/* we only have 8 GPIO can use as input */
+	}
+	return intel_scu_ipc_update_register(GPIO0 + offset,
+							GPIO_DIR, GPIO_DIR);
+}
+
+static int pmic_gpio_direction_output(struct gpio_chip *chip,
+			unsigned offset, int value)
+{
+	int rc = 0;
+
+	if (offset < 8)/* it is GPIO */
+		rc = intel_scu_ipc_update_register(GPIO0 + offset,
+				GPIO_DRV | GPIO_DOU | GPIO_DIR,
+				GPIO_DRV | (value ? GPIO_DOU : 0));
+	else if (offset < 16)/* it is GPOSW */
+		rc = intel_scu_ipc_update_register(GPOSWCTL0 + offset - 8,
+				GPOSW_DRV | GPOSW_DOU | GPOSW_RDRV,
+				GPOSW_DRV | (value ? GPOSW_DOU : 0));
+	else if (offset > 15 && offset < 24)/* it is GPO */
+		rc = intel_scu_ipc_update_register(GPO,
+				1 << (offset - 16),
+				value ? 1 << (offset - 16) : 0);
+	else {
+		printk(KERN_ERR
+			"%s: invalid PMIC GPIO pin %d!\n", __func__, offset);
+		WARN_ON(1);
+	}
+
+	return rc;
+}
+
+static int pmic_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	u8 r;
+	int ret;
+
+	/* we only have 8 GPIO pins we can use as input */
+	if (offset > 8)
+		return -EOPNOTSUPP;
+	ret = intel_scu_ipc_ioread8(GPIO0 + offset, &r);
+	if (ret < 0)
+		return ret;
+	return r & GPIO_DIN;
+}
+
+static void pmic_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	if (offset < 8)/* it is GPIO */
+		intel_scu_ipc_update_register(GPIO0 + offset,
+			GPIO_DRV | GPIO_DOU,
+			GPIO_DRV | (value ? GPIO_DOU : 0));
+	else if (offset < 16)/* it is GPOSW */
+		intel_scu_ipc_update_register(GPOSWCTL0 + offset - 8,
+			GPOSW_DRV | GPOSW_DOU | GPOSW_RDRV,
+			GPOSW_DRV | (value ? GPOSW_DOU : 0));
+	else if (offset > 15 && offset < 24) /* it is GPO */
+		intel_scu_ipc_update_register(GPO,
+			1 << (offset - 16),
+			value ? 1 << (offset - 16) : 0);
+}
+
+static int pmic_irq_type(unsigned irq, unsigned type)
+{
+	struct pmic_gpio *pg = get_irq_chip_data(irq);
+	u32 gpio = irq - pg->irq_base;
+	unsigned long flags;
+
+	if (gpio > pg->chip.ngpio)
+		return -EINVAL;
+
+	spin_lock_irqsave(&pg->irqtypes.lock, flags);
+	pg->irqtypes.trigger[gpio] = type;
+	pg->irqtypes.dirty |=  (1 << gpio);
+	spin_unlock_irqrestore(&pg->irqtypes.lock, flags);
+	schedule_work(&pg->irqtypes.work);
+	return 0;
+}
+
+
+
+static int pmic_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct pmic_gpio *pg = container_of(chip, struct pmic_gpio, chip);
+
+	return pg->irq_base + offset;
+}
+
+/* the gpiointr register is read-clear, so just do nothing. */
+static void pmic_irq_unmask(unsigned irq)
+{
+};
+
+static void pmic_irq_mask(unsigned irq)
+{
+};
+
+static struct irq_chip pmic_irqchip = {
+	.name		= "PMIC-GPIO",
+	.mask		= pmic_irq_mask,
+	.unmask		= pmic_irq_unmask,
+	.set_type	= pmic_irq_type,
+};
+
+static void pmic_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+	struct pmic_gpio *pg = (struct pmic_gpio *)get_irq_data(irq);
+	u8 intsts = *((u8 *)pg->gpiointr + 4);
+	int gpio;
+
+	for (gpio = 0; gpio < 8; gpio++) {
+		if (intsts & (1 << gpio)) {
+			pr_debug("pmic pin %d triggered\n", gpio);
+			generic_handle_irq(pg->irq_base + gpio);
+		}
+	}
+	desc->chip->eoi(irq);
+}
+
+static int __devinit platform_pmic_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int irq = platform_get_irq(pdev, 0);
+	struct intel_pmic_gpio_platform_data *pdata = dev->platform_data;
+
+	struct pmic_gpio *pg;
+	int retval;
+	int i;
+
+	if (irq < 0) {
+		dev_dbg(dev, "no IRQ line\n");
+		return -EINVAL;
+	}
+
+	if (!pdata || !pdata->gpio_base || !pdata->irq_base) {
+		dev_dbg(dev, "incorrect or missing platform data\n");
+		return -EINVAL;
+	}
+
+	pg = kzalloc(sizeof(*pg), GFP_KERNEL);
+	if (!pg)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, pg);
+
+	pg->irq = irq;
+	/* setting up SRAM mapping for GPIOINT register */
+	pg->gpiointr = ioremap_nocache(pdata->gpiointr, 8);
+	if (!pg->gpiointr) {
+		printk(KERN_ERR "%s: Can not map GPIOINT.\n", __func__);
+		retval = -EINVAL;
+		goto err2;
+	}
+	pg->irq_base = pdata->irq_base;
+	pg->chip.label = "intel_pmic";
+	pg->chip.direction_input = pmic_gpio_direction_input;
+	pg->chip.direction_output = pmic_gpio_direction_output;
+	pg->chip.get = pmic_gpio_get;
+	pg->chip.set = pmic_gpio_set;
+	pg->chip.to_irq = pmic_gpio_to_irq;
+	pg->chip.base = pdata->gpio_base;
+	pg->chip.ngpio = NUM_GPIO;
+	pg->chip.can_sleep = 1;
+	pg->chip.dev = dev;
+
+	INIT_WORK(&pg->irqtypes.work, pmic_irqtype_work);
+	spin_lock_init(&pg->irqtypes.lock);
+
+	pg->chip.dev = dev;
+	retval = gpiochip_add(&pg->chip);
+	if (retval) {
+		printk(KERN_ERR "%s: Can not add pmic gpio chip.\n", __func__);
+		goto err;
+	}
+	set_irq_data(pg->irq, pg);
+	set_irq_chained_handler(pg->irq, pmic_irq_handler);
+	for (i = 0; i < 8; i++) {
+		set_irq_chip_and_handler_name(i + pg->irq_base, &pmic_irqchip,
+					handle_simple_irq, "demux");
+		set_irq_chip_data(i + pg->irq_base, pg);
+	}
+	return 0;
+err:
+	iounmap(pg->gpiointr);
+err2:
+	kfree(pg);
+	return retval;
+}
+
+/* at the same time, register a platform driver
+ * this supports the sfi 0.81 fw */
+static struct platform_driver platform_pmic_gpio_driver = {
+	.driver = {
+		.name		= DRIVER_NAME,
+		.owner		= THIS_MODULE,
+	},
+	.probe		= platform_pmic_gpio_probe,
+};
+
+static int __init platform_pmic_gpio_init(void)
+{
+	return platform_driver_register(&platform_pmic_gpio_driver);
+}
+
+subsys_initcall(platform_pmic_gpio_init);
+
+MODULE_AUTHOR("Alek Du <alek.du@intel.com>");
+MODULE_DESCRIPTION("Intel Moorestown PMIC GPIO driver");
+MODULE_LICENSE("GPL v2");

include/linux/intel_pmic_gpio.h

+#ifndef LINUX_INTEL_PMIC_H
+#define LINUX_INTEL_PMIC_H
+
+struct intel_pmic_gpio_platform_data {
+	/* the first IRQ of the chip */
+	unsigned	irq_base;
+	/* number assigned to the first GPIO */
+	unsigned	gpio_base;
+	/* sram address for gpiointr register, the langwell chip will map
+	 * the PMIC spi GPIO expander's GPIOINTR register in sram.
+	 */
+	unsigned	gpiointr;
+};
+
+#endif