ASIC3 driver

This is a patch for the Compaq ASIC3 multi function chip, found in many
PDAs (iPAQs, HTCs...).

It is a simplified version of Paul Sokolovsky's first proposal [1].  With
this code, it is basically a GPIO and IRQ expander.  My plan is to add more
features once this patch gets reviewed and accepted.

[1] http://lkml.org/lkml/2007/5/1/46Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>
Cc: Paul Sokolovsky <pmiscml@gmail.com>
Cc: Ben Dooks <ben@trinity.fluff.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/mfd/Kconfig

@@ -15,6 +15,13 @@ config MFD_SM501
 	  interface. The device may be connected by PCI or local bus with
 	  varying functions enabled.
 
+config MFD_ASIC3
+	bool "Support for Compaq ASIC3"
+	depends on GENERIC_HARDIRQS && ARM
+	 ---help---
+	  This driver supports the ASIC3 multifunction chip found on many
+	  PDAs (mainly iPAQ and HTC based ones)
+
 endmenu
 
 menu "Multimedia Capabilities Port drivers"

drivers/mfd/Makefile

@@ -3,6 +3,7 @@
 #
 
 obj-$(CONFIG_MFD_SM501)		+= sm501.o
+obj-$(CONFIG_MFD_ASIC3)		+= asic3.o
 
 obj-$(CONFIG_MCP)		+= mcp-core.o
 obj-$(CONFIG_MCP_SA11X0)	+= mcp-sa11x0.o

drivers/mfd/asic3.c

+/*
+ * driver/mfd/asic3.c
+ *
+ * Compaq ASIC3 support.
+ *
+ * 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.
+ *
+ * Copyright 2001 Compaq Computer Corporation.
+ * Copyright 2004-2005 Phil Blundell
+ * Copyright 2007 OpenedHand Ltd.
+ *
+ * Authors: Phil Blundell <pb@handhelds.org>,
+ *	    Samuel Ortiz <sameo@openedhand.com>
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+
+#include <linux/mfd/asic3.h>
+
+static inline void asic3_write_register(struct asic3 *asic,
+				 unsigned int reg, u32 value)
+{
+	iowrite16(value, (unsigned long)asic->mapping +
+		  (reg >> asic->bus_shift));
+}
+
+static inline u32 asic3_read_register(struct asic3 *asic,
+			       unsigned int reg)
+{
+	return ioread16((unsigned long)asic->mapping +
+			(reg >> asic->bus_shift));
+}
+
+/* IRQs */
+#define MAX_ASIC_ISR_LOOPS    20
+#define ASIC3_GPIO_Base_INCR \
+	(ASIC3_GPIO_B_Base - ASIC3_GPIO_A_Base)
+
+static void asic3_irq_flip_edge(struct asic3 *asic,
+				u32 base, int bit)
+{
+	u16 edge;
+	unsigned long flags;
+
+	spin_lock_irqsave(&asic->lock, flags);
+	edge = asic3_read_register(asic,
+				   base + ASIC3_GPIO_EdgeTrigger);
+	edge ^= bit;
+	asic3_write_register(asic,
+			     base + ASIC3_GPIO_EdgeTrigger, edge);
+	spin_unlock_irqrestore(&asic->lock, flags);
+}
+
+static void asic3_irq_demux(unsigned int irq, struct irq_desc *desc)
+{
+	int iter, i;
+	unsigned long flags;
+	struct asic3 *asic;
+
+	desc->chip->ack(irq);
+
+	asic = desc->handler_data;
+
+	for (iter = 0 ; iter < MAX_ASIC_ISR_LOOPS; iter++) {
+		u32 status;
+		int bank;
+
+		spin_lock_irqsave(&asic->lock, flags);
+		status = asic3_read_register(asic,
+					     ASIC3_OFFSET(INTR, PIntStat));
+		spin_unlock_irqrestore(&asic->lock, flags);
+
+		/* Check all ten register bits */
+		if ((status & 0x3ff) == 0)
+			break;
+
+		/* Handle GPIO IRQs */
+		for (bank = 0; bank < ASIC3_NUM_GPIO_BANKS; bank++) {
+			if (status & (1 << bank)) {
+				unsigned long base, istat;
+
+				base = ASIC3_GPIO_A_Base
+				       + bank * ASIC3_GPIO_Base_INCR;
+
+				spin_lock_irqsave(&asic->lock, flags);
+				istat = asic3_read_register(asic,
+							    base +
+							    ASIC3_GPIO_IntStatus);
+				/* Clearing IntStatus */
+				asic3_write_register(asic,
+						     base +
+						     ASIC3_GPIO_IntStatus, 0);
+				spin_unlock_irqrestore(&asic->lock, flags);
+
+				for (i = 0; i < ASIC3_GPIOS_PER_BANK; i++) {
+					int bit = (1 << i);
+					unsigned int irqnr;
+
+					if (!(istat & bit))
+						continue;
+
+					irqnr = asic->irq_base +
+						(ASIC3_GPIOS_PER_BANK * bank)
+						+ i;
+					desc = irq_desc + irqnr;
+					desc->handle_irq(irqnr, desc);
+					if (asic->irq_bothedge[bank] & bit)
+						asic3_irq_flip_edge(asic, base,
+								    bit);
+				}
+			}
+		}
+
+		/* Handle remaining IRQs in the status register */
+		for (i = ASIC3_NUM_GPIOS; i < ASIC3_NR_IRQS; i++) {
+			/* They start at bit 4 and go up */
+			if (status & (1 << (i - ASIC3_NUM_GPIOS + 4))) {
+				desc = irq_desc +  + i;
+				desc->handle_irq(asic->irq_base + i,
+						 desc);
+			}
+		}
+	}
+
+	if (iter >= MAX_ASIC_ISR_LOOPS)
+		printk(KERN_ERR "%s: interrupt processing overrun\n",
+		       __FUNCTION__);
+}
+
+static inline int asic3_irq_to_bank(struct asic3 *asic, int irq)
+{
+	int n;
+
+	n = (irq - asic->irq_base) >> 4;
+
+	return (n * (ASIC3_GPIO_B_Base - ASIC3_GPIO_A_Base));
+}
+
+static inline int asic3_irq_to_index(struct asic3 *asic, int irq)
+{
+	return (irq - asic->irq_base) & 0xf;
+}
+
+static void asic3_mask_gpio_irq(unsigned int irq)
+{
+	struct asic3 *asic = get_irq_chip_data(irq);
+	u32 val, bank, index;
+	unsigned long flags;
+
+	bank = asic3_irq_to_bank(asic, irq);
+	index = asic3_irq_to_index(asic, irq);
+
+	spin_lock_irqsave(&asic->lock, flags);
+	val = asic3_read_register(asic, bank + ASIC3_GPIO_Mask);
+	val |= 1 << index;
+	asic3_write_register(asic, bank + ASIC3_GPIO_Mask, val);
+	spin_unlock_irqrestore(&asic->lock, flags);
+}
+
+static void asic3_mask_irq(unsigned int irq)
+{
+	struct asic3 *asic = get_irq_chip_data(irq);
+	int regval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&asic->lock, flags);
+	regval = asic3_read_register(asic,
+				     ASIC3_INTR_Base +
+				     ASIC3_INTR_IntMask);
+
+	regval &= ~(ASIC3_INTMASK_MASK0 <<
+		    (irq - (asic->irq_base + ASIC3_NUM_GPIOS)));
+
+	asic3_write_register(asic,
+			     ASIC3_INTR_Base +
+			     ASIC3_INTR_IntMask,
+			     regval);
+	spin_unlock_irqrestore(&asic->lock, flags);
+}
+
+static void asic3_unmask_gpio_irq(unsigned int irq)
+{
+	struct asic3 *asic = get_irq_chip_data(irq);
+	u32 val, bank, index;
+	unsigned long flags;
+
+	bank = asic3_irq_to_bank(asic, irq);
+	index = asic3_irq_to_index(asic, irq);
+
+	spin_lock_irqsave(&asic->lock, flags);
+	val = asic3_read_register(asic, bank + ASIC3_GPIO_Mask);
+	val &= ~(1 << index);
+	asic3_write_register(asic, bank + ASIC3_GPIO_Mask, val);
+	spin_unlock_irqrestore(&asic->lock, flags);
+}
+
+static void asic3_unmask_irq(unsigned int irq)
+{
+	struct asic3 *asic = get_irq_chip_data(irq);
+	int regval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&asic->lock, flags);
+	regval = asic3_read_register(asic,
+				     ASIC3_INTR_Base +
+				     ASIC3_INTR_IntMask);
+
+	regval |= (ASIC3_INTMASK_MASK0 <<
+		   (irq - (asic->irq_base + ASIC3_NUM_GPIOS)));
+
+	asic3_write_register(asic,
+			     ASIC3_INTR_Base +
+			     ASIC3_INTR_IntMask,
+			     regval);
+	spin_unlock_irqrestore(&asic->lock, flags);
+}
+
+static int asic3_gpio_irq_type(unsigned int irq, unsigned int type)
+{
+	struct asic3 *asic = get_irq_chip_data(irq);
+	u32 bank, index;
+	u16 trigger, level, edge, bit;
+	unsigned long flags;
+
+	bank = asic3_irq_to_bank(asic, irq);
+	index = asic3_irq_to_index(asic, irq);
+	bit = 1<<index;
+
+	spin_lock_irqsave(&asic->lock, flags);
+	level = asic3_read_register(asic,
+				    bank + ASIC3_GPIO_LevelTrigger);
+	edge = asic3_read_register(asic,
+				   bank + ASIC3_GPIO_EdgeTrigger);
+	trigger = asic3_read_register(asic,
+				      bank + ASIC3_GPIO_TriggerType);
+	asic->irq_bothedge[(irq - asic->irq_base) >> 4] &= ~bit;
+
+	if (type == IRQT_RISING) {
+		trigger |= bit;
+		edge |= bit;
+	} else if (type == IRQT_FALLING) {
+		trigger |= bit;
+		edge &= ~bit;
+	} else if (type == IRQT_BOTHEDGE) {
+		trigger |= bit;
+		if (asic3_gpio_get_value(asic, irq - asic->irq_base))
+			edge &= ~bit;
+		else
+			edge |= bit;
+		asic->irq_bothedge[(irq - asic->irq_base) >> 4] |= bit;
+	} else if (type == IRQT_LOW) {
+		trigger &= ~bit;
+		level &= ~bit;
+	} else if (type == IRQT_HIGH) {
+		trigger &= ~bit;
+		level |= bit;
+	} else {
+		/*
+		 * if type == IRQT_NOEDGE, we should mask interrupts, but
+		 * be careful to not unmask them if mask was also called.
+		 * Probably need internal state for mask.
+		 */
+		printk(KERN_NOTICE "asic3: irq type not changed.\n");
+	}
+	asic3_write_register(asic, bank + ASIC3_GPIO_LevelTrigger,
+			     level);
+	asic3_write_register(asic, bank + ASIC3_GPIO_EdgeTrigger,
+			     edge);
+	asic3_write_register(asic, bank + ASIC3_GPIO_TriggerType,
+			     trigger);
+	spin_unlock_irqrestore(&asic->lock, flags);
+	return 0;
+}
+
+static struct irq_chip asic3_gpio_irq_chip = {
+	.name		= "ASIC3-GPIO",
+	.ack		= asic3_mask_gpio_irq,
+	.mask		= asic3_mask_gpio_irq,
+	.unmask		= asic3_unmask_gpio_irq,
+	.set_type	= asic3_gpio_irq_type,
+};
+
+static struct irq_chip asic3_irq_chip = {
+	.name		= "ASIC3",
+	.ack		= asic3_mask_irq,
+	.mask		= asic3_mask_irq,
+	.unmask		= asic3_unmask_irq,
+};
+
+static int asic3_irq_probe(struct platform_device *pdev)
+{
+	struct asic3 *asic = platform_get_drvdata(pdev);
+	unsigned long clksel = 0;
+	unsigned int irq, irq_base;
+
+	asic->irq_nr = platform_get_irq(pdev, 0);
+	if (asic->irq_nr < 0)
+		return asic->irq_nr;
+
+	/* turn on clock to IRQ controller */
+	clksel |= CLOCK_SEL_CX;
+	asic3_write_register(asic, ASIC3_OFFSET(CLOCK, SEL),
+			     clksel);
+
+	irq_base = asic->irq_base;
+
+	for (irq = irq_base; irq < irq_base + ASIC3_NR_IRQS; irq++) {
+		if (irq < asic->irq_base + ASIC3_NUM_GPIOS)
+			set_irq_chip(irq, &asic3_gpio_irq_chip);
+		else
+			set_irq_chip(irq, &asic3_irq_chip);
+
+		set_irq_chip_data(irq, asic);
+		set_irq_handler(irq, handle_level_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+
+	asic3_write_register(asic, ASIC3_OFFSET(INTR, IntMask),
+			     ASIC3_INTMASK_GINTMASK);
+
+	set_irq_chained_handler(asic->irq_nr, asic3_irq_demux);
+	set_irq_type(asic->irq_nr, IRQT_RISING);
+	set_irq_data(asic->irq_nr, asic);
+
+	return 0;
+}
+
+static void asic3_irq_remove(struct platform_device *pdev)
+{
+	struct asic3 *asic = platform_get_drvdata(pdev);
+	unsigned int irq, irq_base;
+
+	irq_base = asic->irq_base;
+
+	for (irq = irq_base; irq < irq_base + ASIC3_NR_IRQS; irq++) {
+		set_irq_flags(irq, 0);
+		set_irq_handler(irq, NULL);
+		set_irq_chip(irq, NULL);
+		set_irq_chip_data(irq, NULL);
+	}
+	set_irq_chained_handler(asic->irq_nr, NULL);
+}
+
+/* GPIOs */
+static inline u32 asic3_get_gpio(struct asic3 *asic, unsigned int base,
+				 unsigned int function)
+{
+	return asic3_read_register(asic, base + function);
+}
+
+static void asic3_set_gpio(struct asic3 *asic, unsigned int base,
+			   unsigned int function, u32 bits, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&asic->lock, flags);
+	val |= (asic3_read_register(asic, base + function) & ~bits);
+
+	asic3_write_register(asic, base + function, val);
+	spin_unlock_irqrestore(&asic->lock, flags);
+}
+
+#define asic3_get_gpio_a(asic, fn) \
+	asic3_get_gpio(asic, ASIC3_GPIO_A_Base, ASIC3_GPIO_##fn)
+#define asic3_get_gpio_b(asic, fn) \
+	asic3_get_gpio(asic, ASIC3_GPIO_B_Base, ASIC3_GPIO_##fn)
+#define asic3_get_gpio_c(asic, fn) \
+	asic3_get_gpio(asic, ASIC3_GPIO_C_Base, ASIC3_GPIO_##fn)
+#define asic3_get_gpio_d(asic, fn) \
+	asic3_get_gpio(asic, ASIC3_GPIO_D_Base, ASIC3_GPIO_##fn)
+
+#define asic3_set_gpio_a(asic, fn, bits, val) \
+	asic3_set_gpio(asic, ASIC3_GPIO_A_Base, ASIC3_GPIO_##fn, bits, val)
+#define asic3_set_gpio_b(asic, fn, bits, val) \
+	asic3_set_gpio(asic, ASIC3_GPIO_B_Base, ASIC3_GPIO_##fn, bits, val)
+#define asic3_set_gpio_c(asic, fn, bits, val) \
+	asic3_set_gpio(asic, ASIC3_GPIO_C_Base, ASIC3_GPIO_##fn, bits, val)
+#define asic3_set_gpio_d(asic, fn, bits, val) \
+	asic3_set_gpio(asic, ASIC3_GPIO_D_Base, ASIC3_GPIO_##fn, bits, val)
+
+#define asic3_set_gpio_banks(asic, fn, bits, pdata, field) 		  \
+	do {								  \
+	     asic3_set_gpio_a((asic), fn, (bits), (pdata)->gpio_a.field); \
+	     asic3_set_gpio_b((asic), fn, (bits), (pdata)->gpio_b.field); \
+	     asic3_set_gpio_c((asic), fn, (bits), (pdata)->gpio_c.field); \
+	     asic3_set_gpio_d((asic), fn, (bits), (pdata)->gpio_d.field); \
+	} while (0)
+
+int asic3_gpio_get_value(struct asic3 *asic, unsigned gpio)
+{
+	u32 mask = ASIC3_GPIO_bit(gpio);
+
+	switch (gpio >> 4) {
+	case ASIC3_GPIO_BANK_A:
+		return asic3_get_gpio_a(asic, Status) & mask;
+	case ASIC3_GPIO_BANK_B:
+		return asic3_get_gpio_b(asic, Status) & mask;
+	case ASIC3_GPIO_BANK_C:
+		return asic3_get_gpio_c(asic, Status) & mask;
+	case ASIC3_GPIO_BANK_D:
+		return asic3_get_gpio_d(asic, Status) & mask;
+	default:
+		printk(KERN_ERR "%s: invalid GPIO value 0x%x",
+		       __FUNCTION__, gpio);
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL(asic3_gpio_get_value);
+
+void asic3_gpio_set_value(struct asic3 *asic, unsigned gpio, int val)
+{
+	u32 mask = ASIC3_GPIO_bit(gpio);
+	u32 bitval = 0;
+	if (val)
+		bitval = mask;
+
+	switch (gpio >> 4) {
+	case ASIC3_GPIO_BANK_A:
+		asic3_set_gpio_a(asic, Out, mask, bitval);
+		return;
+	case ASIC3_GPIO_BANK_B:
+		asic3_set_gpio_b(asic, Out, mask, bitval);
+		return;
+	case ASIC3_GPIO_BANK_C:
+		asic3_set_gpio_c(asic, Out, mask, bitval);
+		return;
+	case ASIC3_GPIO_BANK_D:
+		asic3_set_gpio_d(asic, Out, mask, bitval);
+		return;
+	default:
+		printk(KERN_ERR "%s: invalid GPIO value 0x%x",
+		       __FUNCTION__, gpio);
+		return;
+	}
+}
+EXPORT_SYMBOL(asic3_gpio_set_value);
+
+static int asic3_gpio_probe(struct platform_device *pdev)
+{
+	struct asic3_platform_data *pdata = pdev->dev.platform_data;
+	struct asic3 *asic = platform_get_drvdata(pdev);
+
+	asic3_write_register(asic, ASIC3_GPIO_OFFSET(A, Mask), 0xffff);
+	asic3_write_register(asic, ASIC3_GPIO_OFFSET(B, Mask), 0xffff);
+	asic3_write_register(asic, ASIC3_GPIO_OFFSET(C, Mask), 0xffff);
+	asic3_write_register(asic, ASIC3_GPIO_OFFSET(D, Mask), 0xffff);
+
+	asic3_set_gpio_a(asic, SleepMask, 0xffff, 0xffff);
+	asic3_set_gpio_b(asic, SleepMask, 0xffff, 0xffff);
+	asic3_set_gpio_c(asic, SleepMask, 0xffff, 0xffff);
+	asic3_set_gpio_d(asic, SleepMask, 0xffff, 0xffff);
+
+	if (pdata) {
+		asic3_set_gpio_banks(asic, Out, 0xffff, pdata, init);
+		asic3_set_gpio_banks(asic, Direction, 0xffff, pdata, dir);
+		asic3_set_gpio_banks(asic, SleepMask, 0xffff, pdata,
+				     sleep_mask);
+		asic3_set_gpio_banks(asic, SleepOut, 0xffff, pdata, sleep_out);
+		asic3_set_gpio_banks(asic, BattFaultOut, 0xffff, pdata,
+				     batt_fault_out);
+		asic3_set_gpio_banks(asic, SleepConf, 0xffff, pdata,
+				     sleep_conf);
+		asic3_set_gpio_banks(asic, AltFunction, 0xffff, pdata,
+				     alt_function);
+	}
+
+	return 0;
+}
+
+static void asic3_gpio_remove(struct platform_device *pdev)
+{
+	return;
+}
+
+
+/* Core */
+static int asic3_probe(struct platform_device *pdev)
+{
+	struct asic3_platform_data *pdata = pdev->dev.platform_data;
+	struct asic3 *asic;
+	struct resource *mem;
+	unsigned long clksel;
+	int ret;
+
+	asic = kzalloc(sizeof(struct asic3), GFP_KERNEL);
+	if (!asic)
+		return -ENOMEM;
+
+	spin_lock_init(&asic->lock);
+	platform_set_drvdata(pdev, asic);
+	asic->dev = &pdev->dev;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		ret = -ENOMEM;
+		printk(KERN_ERR "asic3: no MEM resource\n");
+		goto err_out_1;
+	}
+
+	asic->mapping = ioremap(mem->start, PAGE_SIZE);
+	if (!asic->mapping) {
+		ret = -ENOMEM;
+		printk(KERN_ERR "asic3: couldn't ioremap\n");
+		goto err_out_1;
+	}
+
+	asic->irq_base = pdata->irq_base;
+
+	if (pdata && pdata->bus_shift)
+		asic->bus_shift = 2 - pdata->bus_shift;
+	else
+		asic->bus_shift = 0;
+
+	clksel = 0;
+	asic3_write_register(asic, ASIC3_OFFSET(CLOCK, SEL), clksel);
+
+	ret = asic3_irq_probe(pdev);
+	if (ret < 0) {
+		printk(KERN_ERR "asic3: couldn't probe IRQs\n");
+		goto err_out_2;
+	}
+	asic3_gpio_probe(pdev);
+
+	if (pdata->children) {
+		int i;
+		for (i = 0; i < pdata->n_children; i++) {
+			pdata->children[i]->dev.parent = &pdev->dev;
+			platform_device_register(pdata->children[i]);
+		}
+	}
+
+	printk(KERN_INFO "ASIC3 Core driver\n");
+
+	return 0;
+
+ err_out_2:
+	iounmap(asic->mapping);
+ err_out_1:
+	kfree(asic);
+
+	return ret;
+}
+
+static int asic3_remove(struct platform_device *pdev)
+{
+	struct asic3 *asic = platform_get_drvdata(pdev);
+
+	asic3_gpio_remove(pdev);
+	asic3_irq_remove(pdev);
+
+	asic3_write_register(asic, ASIC3_OFFSET(CLOCK, SEL), 0);
+
+	iounmap(asic->mapping);
+
+	kfree(asic);
+
+	return 0;
+}
+
+static void asic3_shutdown(struct platform_device *pdev)
+{
+}
+
+static struct platform_driver asic3_device_driver = {
+	.driver		= {
+		.name	= "asic3",
+	},
+	.probe		= asic3_probe,
+	.remove		= __devexit_p(asic3_remove),
+	.shutdown	= asic3_shutdown,
+};
+
+static int __init asic3_init(void)
+{
+	int retval = 0;
+	retval = platform_driver_register(&asic3_device_driver);
+	return retval;
+}
+
+subsys_initcall(asic3_init);