linux/drivers/mfd/htc-pasic3.c
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   1/*
   2 * Core driver for HTC PASIC3 LED/DS1WM chip.
   3 *
   4 * Copyright (C) 2006 Philipp Zabel <philipp.zabel@gmail.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; version 2 of the License.
   9 */
  10
  11#include <linux/init.h>
  12#include <linux/module.h>
  13#include <linux/platform_device.h>
  14
  15#include <linux/gpio.h>
  16#include <linux/io.h>
  17#include <linux/irq.h>
  18#include <linux/interrupt.h>
  19#include <linux/mfd/core.h>
  20#include <linux/mfd/ds1wm.h>
  21#include <linux/mfd/htc-pasic3.h>
  22#include <linux/slab.h>
  23
  24struct pasic3_data {
  25        void __iomem *mapping;
  26        unsigned int bus_shift;
  27};
  28
  29#define REG_ADDR  5
  30#define REG_DATA  6
  31
  32#define READ_MODE 0x80
  33
  34/*
  35 * write to a secondary register on the PASIC3
  36 */
  37void pasic3_write_register(struct device *dev, u32 reg, u8 val)
  38{
  39        struct pasic3_data *asic = dev_get_drvdata(dev);
  40        int bus_shift = asic->bus_shift;
  41        void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
  42        void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
  43
  44        __raw_writeb(~READ_MODE & reg, addr);
  45        __raw_writeb(val, data);
  46}
  47EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */
  48
  49/*
  50 * read from a secondary register on the PASIC3
  51 */
  52u8 pasic3_read_register(struct device *dev, u32 reg)
  53{
  54        struct pasic3_data *asic = dev_get_drvdata(dev);
  55        int bus_shift = asic->bus_shift;
  56        void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
  57        void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
  58
  59        __raw_writeb(READ_MODE | reg, addr);
  60        return __raw_readb(data);
  61}
  62EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */
  63
  64/*
  65 * LEDs
  66 */
  67
  68static struct mfd_cell led_cell __initdata = {
  69        .name = "leds-pasic3",
  70};
  71
  72/*
  73 * DS1WM
  74 */
  75
  76static int ds1wm_enable(struct platform_device *pdev)
  77{
  78        struct device *dev = pdev->dev.parent;
  79        int c;
  80
  81        c = pasic3_read_register(dev, 0x28);
  82        pasic3_write_register(dev, 0x28, c & 0x7f);
  83
  84        dev_dbg(dev, "DS1WM OWM_EN low (active) %02x\n", c & 0x7f);
  85        return 0;
  86}
  87
  88static int ds1wm_disable(struct platform_device *pdev)
  89{
  90        struct device *dev = pdev->dev.parent;
  91        int c;
  92
  93        c = pasic3_read_register(dev, 0x28);
  94        pasic3_write_register(dev, 0x28, c | 0x80);
  95
  96        dev_dbg(dev, "DS1WM OWM_EN high (inactive) %02x\n", c | 0x80);
  97        return 0;
  98}
  99
 100static struct ds1wm_driver_data ds1wm_pdata = {
 101        .active_high = 0,
 102};
 103
 104static struct resource ds1wm_resources[] __initdata = {
 105        [0] = {
 106                .start  = 0,
 107                .flags  = IORESOURCE_MEM,
 108        },
 109        [1] = {
 110                .start  = 0,
 111                .end    = 0,
 112                .flags  = IORESOURCE_IRQ,
 113        },
 114};
 115
 116static struct mfd_cell ds1wm_cell __initdata = {
 117        .name          = "ds1wm",
 118        .enable        = ds1wm_enable,
 119        .disable       = ds1wm_disable,
 120        .mfd_data      = &ds1wm_pdata,
 121        .num_resources = 2,
 122        .resources     = ds1wm_resources,
 123};
 124
 125static int __init pasic3_probe(struct platform_device *pdev)
 126{
 127        struct pasic3_platform_data *pdata = pdev->dev.platform_data;
 128        struct device *dev = &pdev->dev;
 129        struct pasic3_data *asic;
 130        struct resource *r;
 131        int ret;
 132        int irq = 0;
 133
 134        r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 135        if (r) {
 136                ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
 137                        (IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
 138                irq = r->start;
 139        }
 140
 141        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 142        if (!r)
 143                return -ENXIO;
 144
 145        if (!request_mem_region(r->start, resource_size(r), "pasic3"))
 146                return -EBUSY;
 147
 148        asic = kzalloc(sizeof(struct pasic3_data), GFP_KERNEL);
 149        if (!asic)
 150                return -ENOMEM;
 151
 152        platform_set_drvdata(pdev, asic);
 153
 154        asic->mapping = ioremap(r->start, resource_size(r));
 155        if (!asic->mapping) {
 156                dev_err(dev, "couldn't ioremap PASIC3\n");
 157                kfree(asic);
 158                return -ENOMEM;
 159        }
 160
 161        /* calculate bus shift from mem resource */
 162        asic->bus_shift = (resource_size(r) - 5) >> 3;
 163
 164        if (pdata && pdata->clock_rate) {
 165                ds1wm_pdata.clock_rate = pdata->clock_rate;
 166                /* the first 5 PASIC3 registers control the DS1WM */
 167                ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
 168                ret = mfd_add_devices(&pdev->dev, pdev->id,
 169                                &ds1wm_cell, 1, r, irq);
 170                if (ret < 0)
 171                        dev_warn(dev, "failed to register DS1WM\n");
 172        }
 173
 174        if (pdata && pdata->led_pdata) {
 175                ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r, 0);
 176                if (ret < 0)
 177                        dev_warn(dev, "failed to register LED device\n");
 178        }
 179
 180        return 0;
 181}
 182
 183static int pasic3_remove(struct platform_device *pdev)
 184{
 185        struct pasic3_data *asic = platform_get_drvdata(pdev);
 186        struct resource *r;
 187
 188        mfd_remove_devices(&pdev->dev);
 189
 190        iounmap(asic->mapping);
 191        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 192        release_mem_region(r->start, resource_size(r));
 193        kfree(asic);
 194        return 0;
 195}
 196
 197MODULE_ALIAS("platform:pasic3");
 198
 199static struct platform_driver pasic3_driver = {
 200        .driver         = {
 201                .name   = "pasic3",
 202        },
 203        .remove         = pasic3_remove,
 204};
 205
 206static int __init pasic3_base_init(void)
 207{
 208        return platform_driver_probe(&pasic3_driver, pasic3_probe);
 209}
 210
 211static void __exit pasic3_base_exit(void)
 212{
 213        platform_driver_unregister(&pasic3_driver);
 214}
 215
 216module_init(pasic3_base_init);
 217module_exit(pasic3_base_exit);
 218
 219MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
 220MODULE_DESCRIPTION("Core driver for HTC PASIC3");
 221MODULE_LICENSE("GPL");
 222