Pileus Git - ~andy/linux/blob - drivers/acpi/acpi_lpss.c

   1 /*
   2  * ACPI support for Intel Lynxpoint LPSS.
   3  *
   4  * Copyright (C) 2013, Intel Corporation
   5  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
   6  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/clk.h>
  15 #include <linux/clkdev.h>
  16 #include <linux/clk-provider.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/platform_data/clk-lpss.h>
  21 #include <linux/pm_runtime.h>
  22
  23 #include "internal.h"
  24
  25 ACPI_MODULE_NAME("acpi_lpss");
  26
  27 #define LPSS_CLK_SIZE   0x04
  28 #define LPSS_LTR_SIZE   0x18
  29
  30 /* Offsets relative to LPSS_PRIVATE_OFFSET */
  31 #define LPSS_GENERAL                    0x08
  32 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
  33 #define LPSS_SW_LTR                     0x10
  34 #define LPSS_AUTO_LTR                   0x14
  35
  36 struct lpss_device_desc {
  37         bool clk_required;
  38         const char *clk_parent;
  39         bool ltr_required;
  40         unsigned int prv_offset;
  41 };
  42
  43 struct lpss_private_data {
  44         void __iomem *mmio_base;
  45         resource_size_t mmio_size;
  46         struct clk *clk;
  47         const struct lpss_device_desc *dev_desc;
  48 };
  49
  50 static struct lpss_device_desc lpt_dev_desc = {
  51         .clk_required = true,
  52         .clk_parent = "lpss_clk",
  53         .prv_offset = 0x800,
  54         .ltr_required = true,
  55 };
  56
  57 static struct lpss_device_desc lpt_sdio_dev_desc = {
  58         .prv_offset = 0x1000,
  59         .ltr_required = true,
  60 };
  61
  62 static const struct acpi_device_id acpi_lpss_device_ids[] = {
  63         /* Lynxpoint LPSS devices */
  64         { "INT33C0", (unsigned long)&lpt_dev_desc },
  65         { "INT33C1", (unsigned long)&lpt_dev_desc },
  66         { "INT33C2", (unsigned long)&lpt_dev_desc },
  67         { "INT33C3", (unsigned long)&lpt_dev_desc },
  68         { "INT33C4", (unsigned long)&lpt_dev_desc },
  69         { "INT33C5", (unsigned long)&lpt_dev_desc },
  70         { "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
  71         { "INT33C7", },
  72
  73         { }
  74 };
  75
  76 static int is_memory(struct acpi_resource *res, void *not_used)
  77 {
  78         struct resource r;
  79         return !acpi_dev_resource_memory(res, &r);
  80 }
  81
  82 /* LPSS main clock device. */
  83 static struct platform_device *lpss_clk_dev;
  84
  85 static inline void lpt_register_clock_device(void)
  86 {
  87         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
  88 }
  89
  90 static int register_device_clock(struct acpi_device *adev,
  91                                  struct lpss_private_data *pdata)
  92 {
  93         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
  94
  95         if (!lpss_clk_dev)
  96                 lpt_register_clock_device();
  97
  98         if (!dev_desc->clk_parent || !pdata->mmio_base
  99             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 100                 return -ENODATA;
 101
 102         pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
 103                                        dev_desc->clk_parent, 0,
 104                                        pdata->mmio_base + dev_desc->prv_offset,
 105                                        0, 0, NULL);
 106         if (IS_ERR(pdata->clk))
 107                 return PTR_ERR(pdata->clk);
 108
 109         clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev));
 110         return 0;
 111 }
 112
 113 static int acpi_lpss_create_device(struct acpi_device *adev,
 114                                    const struct acpi_device_id *id)
 115 {
 116         struct lpss_device_desc *dev_desc;
 117         struct lpss_private_data *pdata;
 118         struct resource_list_entry *rentry;
 119         struct list_head resource_list;
 120         int ret;
 121
 122         dev_desc = (struct lpss_device_desc *)id->driver_data;
 123         if (!dev_desc)
 124                 return acpi_create_platform_device(adev, id);
 125
 126         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 127         if (!pdata)
 128                 return -ENOMEM;
 129
 130         INIT_LIST_HEAD(&resource_list);
 131         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 132         if (ret < 0)
 133                 goto err_out;
 134
 135         list_for_each_entry(rentry, &resource_list, node)
 136                 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
 137                         pdata->mmio_size = resource_size(&rentry->res);
 138                         pdata->mmio_base = ioremap(rentry->res.start,
 139                                                    pdata->mmio_size);
 140                         pdata->dev_desc = dev_desc;
 141                         break;
 142                 }
 143
 144         acpi_dev_free_resource_list(&resource_list);
 145
 146         if (dev_desc->clk_required) {
 147                 ret = register_device_clock(adev, pdata);
 148                 if (ret) {
 149                         /*
 150                          * Skip the device, but don't terminate the namespace
 151                          * scan.
 152                          */
 153                         kfree(pdata);
 154                         return 0;
 155                 }
 156         }
 157
 158         adev->driver_data = pdata;
 159         ret = acpi_create_platform_device(adev, id);
 160         if (ret > 0)
 161                 return ret;
 162
 163         adev->driver_data = NULL;
 164
 165  err_out:
 166         kfree(pdata);
 167         return ret;
 168 }
 169
 170 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 171 {
 172         struct acpi_device *adev;
 173         struct lpss_private_data *pdata;
 174         unsigned long flags;
 175         int ret;
 176
 177         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 178         if (WARN_ON(ret))
 179                 return ret;
 180
 181         spin_lock_irqsave(&dev->power.lock, flags);
 182         if (pm_runtime_suspended(dev)) {
 183                 ret = -EAGAIN;
 184                 goto out;
 185         }
 186         pdata = acpi_driver_data(adev);
 187         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 188                 ret = -ENODEV;
 189                 goto out;
 190         }
 191         *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 192
 193  out:
 194         spin_unlock_irqrestore(&dev->power.lock, flags);
 195         return ret;
 196 }
 197
 198 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 199                              char *buf)
 200 {
 201         u32 ltr_value = 0;
 202         unsigned int reg;
 203         int ret;
 204
 205         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 206         ret = lpss_reg_read(dev, reg, &ltr_value);
 207         if (ret)
 208                 return ret;
 209
 210         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 211 }
 212
 213 static ssize_t lpss_ltr_mode_show(struct device *dev,
 214                                   struct device_attribute *attr, char *buf)
 215 {
 216         u32 ltr_mode = 0;
 217         char *outstr;
 218         int ret;
 219
 220         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 221         if (ret)
 222                 return ret;
 223
 224         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 225         return sprintf(buf, "%s\n", outstr);
 226 }
 227
 228 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 229 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 230 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 231
 232 static struct attribute *lpss_attrs[] = {
 233         &dev_attr_auto_ltr.attr,
 234         &dev_attr_sw_ltr.attr,
 235         &dev_attr_ltr_mode.attr,
 236         NULL,
 237 };
 238
 239 static struct attribute_group lpss_attr_group = {
 240         .attrs = lpss_attrs,
 241         .name = "lpss_ltr",
 242 };
 243
 244 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 245                                      unsigned long action, void *data)
 246 {
 247         struct platform_device *pdev = to_platform_device(data);
 248         struct lpss_private_data *pdata;
 249         struct acpi_device *adev;
 250         const struct acpi_device_id *id;
 251         int ret = 0;
 252
 253         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 254         if (!id || !id->driver_data)
 255                 return 0;
 256
 257         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 258                 return 0;
 259
 260         pdata = acpi_driver_data(adev);
 261         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 262                 return 0;
 263
 264         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 265                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 266                 return 0;
 267         }
 268
 269         if (action == BUS_NOTIFY_ADD_DEVICE)
 270                 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
 271         else if (action == BUS_NOTIFY_DEL_DEVICE)
 272                 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 273
 274         return ret;
 275 }
 276
 277 static struct notifier_block acpi_lpss_nb = {
 278         .notifier_call = acpi_lpss_platform_notify,
 279 };
 280
 281 static struct acpi_scan_handler lpss_handler = {
 282         .ids = acpi_lpss_device_ids,
 283         .attach = acpi_lpss_create_device,
 284 };
 285
 286 void __init acpi_lpss_init(void)
 287 {
 288         if (!lpt_clk_init()) {
 289                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
 290                 acpi_scan_add_handler(&lpss_handler);
 291         }
 292 }