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         .reset_recover_delay = 1,
 103 };
 104
 105 static struct resource ds1wm_resources[] __initdata = {
 106         [0] = {
 107                 .start  = 0,
 108                 .flags  = IORESOURCE_MEM,
 109         },
 110         [1] = {
 111                 .start  = 0,
 112                 .end    = 0,
 113                 .flags  = IORESOURCE_IRQ,
 114         },
 115 };
 116
 117 static const struct mfd_cell ds1wm_cell __initconst = {
 118         .name          = "ds1wm",
 119         .enable        = ds1wm_enable,
 120         .disable       = ds1wm_disable,
 121         .platform_data = &ds1wm_pdata,
 122         .pdata_size    = sizeof(ds1wm_pdata),
 123         .num_resources = 2,
 124         .resources     = ds1wm_resources,
 125 };
 126
 127 static int __init pasic3_probe(struct platform_device *pdev)
 128 {
 129         struct pasic3_platform_data *pdata = dev_get_platdata(&pdev->dev);
 130         struct device *dev = &pdev->dev;
 131         struct pasic3_data *asic;
 132         struct resource *r;
 133         int ret;
 134         int irq = 0;
 135
 136         r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 137         if (r) {
 138                 ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
 139                         (IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
 140                 irq = r->start;
 141         }
 142
 143         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 144         if (!r)
 145                 return -ENXIO;
 146
 147         if (!request_mem_region(r->start, resource_size(r), "pasic3"))
 148                 return -EBUSY;
 149
 150         asic = devm_kzalloc(dev, sizeof(struct pasic3_data), GFP_KERNEL);
 151         if (!asic)
 152                 return -ENOMEM;
 153
 154         platform_set_drvdata(pdev, asic);
 155
 156         asic->mapping = ioremap(r->start, resource_size(r));
 157         if (!asic->mapping) {
 158                 dev_err(dev, "couldn't ioremap PASIC3\n");
 159                 return -ENOMEM;
 160         }
 161
 162         /* calculate bus shift from mem resource */
 163         asic->bus_shift = (resource_size(r) - 5) >> 3;
 164
 165         if (pdata && pdata->clock_rate) {
 166                 ds1wm_pdata.clock_rate = pdata->clock_rate;
 167                 /* the first 5 PASIC3 registers control the DS1WM */
 168                 ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
 169                 ret = mfd_add_devices(&pdev->dev, pdev->id,
 170                                       &ds1wm_cell, 1, r, irq, NULL);
 171                 if (ret < 0)
 172                         dev_warn(dev, "failed to register DS1WM\n");
 173         }
 174
 175         if (pdata && pdata->led_pdata) {
 176                 led_cell.platform_data = pdata->led_pdata;
 177                 led_cell.pdata_size = sizeof(struct pasic3_leds_machinfo);
 178                 ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r,
 179                                       0, NULL);
 180                 if (ret < 0)
 181                         dev_warn(dev, "failed to register LED device\n");
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int pasic3_remove(struct platform_device *pdev)
 188 {
 189         struct pasic3_data *asic = platform_get_drvdata(pdev);
 190         struct resource *r;
 191
 192         mfd_remove_devices(&pdev->dev);
 193
 194         iounmap(asic->mapping);
 195         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 196         release_mem_region(r->start, resource_size(r));
 197         return 0;
 198 }
 199
 200 MODULE_ALIAS("platform:pasic3");
 201
 202 static struct platform_driver pasic3_driver = {
 203         .driver         = {
 204                 .name   = "pasic3",
 205         },
 206         .remove         = pasic3_remove,
 207 };
 208
 209 module_platform_driver_probe(pasic3_driver, pasic3_probe);
 210
 211 MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
 212 MODULE_DESCRIPTION("Core driver for HTC PASIC3");
 213 MODULE_LICENSE("GPL");