drivers/mfd/htc-pasic3.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Core driver for HTC PASIC3 LED/DS1WM chip.
   4  *
   5  * Copyright (C) 2006 Philipp Zabel <philipp.zabel@gmail.com>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/platform_device.h>
  11
  12 #include <linux/gpio.h>
  13 #include <linux/io.h>
  14 #include <linux/irq.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/mfd/core.h>
  17 #include <linux/mfd/ds1wm.h>
  18 #include <linux/mfd/htc-pasic3.h>
  19 #include <linux/slab.h>
  20
  21 struct pasic3_data {
  22         void __iomem *mapping;
  23         unsigned int bus_shift;
  24 };
  25
  26 #define REG_ADDR  5
  27 #define REG_DATA  6
  28
  29 #define READ_MODE 0x80
  30
  31 /*
  32  * write to a secondary register on the PASIC3
  33  */
  34 void pasic3_write_register(struct device *dev, u32 reg, u8 val)
  35 {
  36         struct pasic3_data *asic = dev_get_drvdata(dev);
  37         int bus_shift = asic->bus_shift;
  38         void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
  39         void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
  40
  41         __raw_writeb(~READ_MODE & reg, addr);
  42         __raw_writeb(val, data);
  43 }
  44 EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */
  45
  46 /*
  47  * read from a secondary register on the PASIC3
  48  */
  49 u8 pasic3_read_register(struct device *dev, u32 reg)
  50 {
  51         struct pasic3_data *asic = dev_get_drvdata(dev);
  52         int bus_shift = asic->bus_shift;
  53         void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
  54         void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
  55
  56         __raw_writeb(READ_MODE | reg, addr);
  57         return __raw_readb(data);
  58 }
  59 EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */
  60
  61 /*
  62  * LEDs
  63  */
  64
  65 static struct mfd_cell led_cell __initdata = {
  66         .name = "leds-pasic3",
  67 };
  68
  69 /*
  70  * DS1WM
  71  */
  72
  73 static int ds1wm_enable(struct platform_device *pdev)
  74 {
  75         struct device *dev = pdev->dev.parent;
  76         int c;
  77
  78         c = pasic3_read_register(dev, 0x28);
  79         pasic3_write_register(dev, 0x28, c & 0x7f);
  80
  81         dev_dbg(dev, "DS1WM OWM_EN low (active) %02x\n", c & 0x7f);
  82         return 0;
  83 }
  84
  85 static int ds1wm_disable(struct platform_device *pdev)
  86 {
  87         struct device *dev = pdev->dev.parent;
  88         int c;
  89
  90         c = pasic3_read_register(dev, 0x28);
  91         pasic3_write_register(dev, 0x28, c | 0x80);
  92
  93         dev_dbg(dev, "DS1WM OWM_EN high (inactive) %02x\n", c | 0x80);
  94         return 0;
  95 }
  96
  97 static struct ds1wm_driver_data ds1wm_pdata = {
  98         .active_high = 0,
  99         .reset_recover_delay = 1,
 100 };
 101
 102 static struct resource ds1wm_resources[] __initdata = {
 103         [0] = {
 104                 .start  = 0,
 105                 .flags  = IORESOURCE_MEM,
 106         },
 107         [1] = {
 108                 .start  = 0,
 109                 .end    = 0,
 110                 .flags  = IORESOURCE_IRQ,
 111         },
 112 };
 113
 114 static const struct mfd_cell ds1wm_cell __initconst = {
 115         .name          = "ds1wm",
 116         .enable        = ds1wm_enable,
 117         .disable       = ds1wm_disable,
 118         .platform_data = &ds1wm_pdata,
 119         .pdata_size    = sizeof(ds1wm_pdata),
 120         .num_resources = 2,
 121         .resources     = ds1wm_resources,
 122 };
 123
 124 static int __init pasic3_probe(struct platform_device *pdev)
 125 {
 126         struct pasic3_platform_data *pdata = dev_get_platdata(&pdev->dev);
 127         struct device *dev = &pdev->dev;
 128         struct pasic3_data *asic;
 129         struct resource *r;
 130         int ret;
 131         int irq = 0;
 132
 133         r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 134         if (r) {
 135                 ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
 136                         (IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
 137                 irq = r->start;
 138         }
 139
 140         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 141         if (!r)
 142                 return -ENXIO;
 143
 144         if (!request_mem_region(r->start, resource_size(r), "pasic3"))
 145                 return -EBUSY;
 146
 147         asic = devm_kzalloc(dev, sizeof(struct pasic3_data), GFP_KERNEL);
 148         if (!asic)
 149                 return -ENOMEM;
 150
 151         platform_set_drvdata(pdev, asic);
 152
 153         asic->mapping = ioremap(r->start, resource_size(r));
 154         if (!asic->mapping) {
 155                 dev_err(dev, "couldn't ioremap PASIC3\n");
 156                 return -ENOMEM;
 157         }
 158
 159         /* calculate bus shift from mem resource */
 160         asic->bus_shift = (resource_size(r) - 5) >> 3;
 161
 162         if (pdata && pdata->clock_rate) {
 163                 ds1wm_pdata.clock_rate = pdata->clock_rate;
 164                 /* the first 5 PASIC3 registers control the DS1WM */
 165                 ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
 166                 ret = mfd_add_devices(&pdev->dev, pdev->id,
 167                                       &ds1wm_cell, 1, r, irq, NULL);
 168                 if (ret < 0)
 169                         dev_warn(dev, "failed to register DS1WM\n");
 170         }
 171
 172         if (pdata && pdata->led_pdata) {
 173                 led_cell.platform_data = pdata->led_pdata;
 174                 led_cell.pdata_size = sizeof(struct pasic3_leds_machinfo);
 175                 ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r,
 176                                       0, NULL);
 177                 if (ret < 0)
 178                         dev_warn(dev, "failed to register LED device\n");
 179         }
 180
 181         return 0;
 182 }
 183
 184 static int pasic3_remove(struct platform_device *pdev)
 185 {
 186         struct pasic3_data *asic = platform_get_drvdata(pdev);
 187         struct resource *r;
 188
 189         mfd_remove_devices(&pdev->dev);
 190
 191         iounmap(asic->mapping);
 192         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 193         release_mem_region(r->start, resource_size(r));
 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 module_platform_driver_probe(pasic3_driver, pasic3_probe);
 207
 208 MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
 209 MODULE_DESCRIPTION("Core driver for HTC PASIC3");
 210 MODULE_LICENSE("GPL");