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/2007/5/1/46

Signed-off-by: Samuel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 596 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 25716193a534..0c886c882385 100644
--- a/drivers/mfd/Kconfig
+++ b/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"
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 51432091b323..521cd5cb68af 100644
--- a/drivers/mfd/Makefile
+++ b/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
diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
new file mode 100644
index 000000000000..63fb1ff3ad10
--- /dev/null
+++ b/drivers/mfd/asic3.c
@@ -0,0 +1,588 @@
+/*
+ * 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);