drivers/mfd/htc-pasic3.c

   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
  24 struct 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  */
  37 void 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 }
  47 EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */
  48
  49 /*
  50  * read from a secondary register on the PASIC3
  51  */
  52 u8 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 }
  62 EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */
  63
  64 /*
  65  * LEDs
  66  */
  67
  68 static struct mfd_cell led_cell __initdata = {
  69         .name = "leds-pasic3",
  70 };
  71
  72 /*
  73  * DS1WM
  74  */
  75
  76 static 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
  88 static 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
 100 static struct ds1wm_driver_data ds1wm_pdata = {
 101         .active_high = 0,
 102 };
 103
 104 static 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
 116 static 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
 125 static 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
 183 static 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
 197 MODULE_ALIAS("platform:pasic3");
 198
 199 static struct platform_driver pasic3_driver = {
 200         .driver         = {
 201                 .name   = "pasic3",
 202         },
 203         .remove         = pasic3_remove,
 204 };
 205
 206 static int __init pasic3_base_init(void)
 207 {
 208         return platform_driver_probe(&pasic3_driver, pasic3_probe);
 209 }
 210
 211 static void __exit pasic3_base_exit(void)
 212 {
 213         platform_driver_unregister(&pasic3_driver);
 214 }
 215
 216 module_init(pasic3_base_init);
 217 module_exit(pasic3_base_exit);
 218
 219 MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
 220 MODULE_DESCRIPTION("Core driver for HTC PASIC3");
 221 MODULE_LICENSE("GPL");