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 *clkdev_name; 39 bool ltr_required; 40 unsigned int prv_offset; 41 }; 42 43 static struct lpss_device_desc lpss_dma_desc = { 44 .clk_required = true, 45 .clkdev_name = "hclk", 46 }; 47 48 struct lpss_private_data { 49 void __iomem *mmio_base; 50 resource_size_t mmio_size; 51 struct clk *clk; 52 const struct lpss_device_desc *dev_desc; 53 }; 54 55 static struct lpss_device_desc lpt_dev_desc = { 56 .clk_required = true, 57 .prv_offset = 0x800, 58 .ltr_required = true, 59 }; 60 61 static struct lpss_device_desc lpt_sdio_dev_desc = { 62 .prv_offset = 0x1000, 63 .ltr_required = true, 64 }; 65 66 static const struct acpi_device_id acpi_lpss_device_ids[] = { 67 /* Generic LPSS devices */ 68 { "INTL9C60", (unsigned long)&lpss_dma_desc }, 69 70 /* Lynxpoint LPSS devices */ 71 { "INT33C0", (unsigned long)&lpt_dev_desc }, 72 { "INT33C1", (unsigned long)&lpt_dev_desc }, 73 { "INT33C2", (unsigned long)&lpt_dev_desc }, 74 { "INT33C3", (unsigned long)&lpt_dev_desc }, 75 { "INT33C4", (unsigned long)&lpt_dev_desc }, 76 { "INT33C5", (unsigned long)&lpt_dev_desc }, 77 { "INT33C6", (unsigned long)&lpt_sdio_dev_desc }, 78 { "INT33C7", }, 79 80 { } 81 }; 82 83 static int is_memory(struct acpi_resource *res, void *not_used) 84 { 85 struct resource r; 86 return !acpi_dev_resource_memory(res, &r); 87 } 88 89 /* LPSS main clock device. */ 90 static struct platform_device *lpss_clk_dev; 91 92 static inline void lpt_register_clock_device(void) 93 { 94 lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0); 95 } 96 97 static int register_device_clock(struct acpi_device *adev, 98 struct lpss_private_data *pdata) 99 { 100 const struct lpss_device_desc *dev_desc = pdata->dev_desc; 101 struct lpss_clk_data *clk_data; 102 103 if (!lpss_clk_dev) 104 lpt_register_clock_device(); 105 106 clk_data = platform_get_drvdata(lpss_clk_dev); 107 if (!clk_data) 108 return -ENODEV; 109 110 if (dev_desc->clkdev_name) { 111 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name, 112 dev_name(&adev->dev)); 113 return 0; 114 } 115 116 if (!pdata->mmio_base 117 || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE) 118 return -ENODATA; 119 120 pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev), 121 clk_data->name, 0, 122 pdata->mmio_base + dev_desc->prv_offset, 123 0, 0, NULL); 124 if (IS_ERR(pdata->clk)) 125 return PTR_ERR(pdata->clk); 126 127 clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev)); 128 return 0; 129 } 130 131 static int acpi_lpss_create_device(struct acpi_device *adev, 132 const struct acpi_device_id *id) 133 { 134 struct lpss_device_desc *dev_desc; 135 struct lpss_private_data *pdata; 136 struct resource_list_entry *rentry; 137 struct list_head resource_list; 138 int ret; 139 140 dev_desc = (struct lpss_device_desc *)id->driver_data; 141 if (!dev_desc) 142 return acpi_create_platform_device(adev, id); 143 144 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 145 if (!pdata) 146 return -ENOMEM; 147 148 INIT_LIST_HEAD(&resource_list); 149 ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL); 150 if (ret < 0) 151 goto err_out; 152 153 list_for_each_entry(rentry, &resource_list, node) 154 if (resource_type(&rentry->res) == IORESOURCE_MEM) { 155 pdata->mmio_size = resource_size(&rentry->res); 156 pdata->mmio_base = ioremap(rentry->res.start, 157 pdata->mmio_size); 158 pdata->dev_desc = dev_desc; 159 break; 160 } 161 162 acpi_dev_free_resource_list(&resource_list); 163 164 if (dev_desc->clk_required) { 165 ret = register_device_clock(adev, pdata); 166 if (ret) { 167 /* 168 * Skip the device, but don't terminate the namespace 169 * scan. 170 */ 171 kfree(pdata); 172 return 0; 173 } 174 } 175 176 adev->driver_data = pdata; 177 ret = acpi_create_platform_device(adev, id); 178 if (ret > 0) 179 return ret; 180 181 adev->driver_data = NULL; 182 183 err_out: 184 kfree(pdata); 185 return ret; 186 } 187 188 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val) 189 { 190 struct acpi_device *adev; 191 struct lpss_private_data *pdata; 192 unsigned long flags; 193 int ret; 194 195 ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev); 196 if (WARN_ON(ret)) 197 return ret; 198 199 spin_lock_irqsave(&dev->power.lock, flags); 200 if (pm_runtime_suspended(dev)) { 201 ret = -EAGAIN; 202 goto out; 203 } 204 pdata = acpi_driver_data(adev); 205 if (WARN_ON(!pdata || !pdata->mmio_base)) { 206 ret = -ENODEV; 207 goto out; 208 } 209 *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg); 210 211 out: 212 spin_unlock_irqrestore(&dev->power.lock, flags); 213 return ret; 214 } 215 216 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr, 217 char *buf) 218 { 219 u32 ltr_value = 0; 220 unsigned int reg; 221 int ret; 222 223 reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR; 224 ret = lpss_reg_read(dev, reg, <r_value); 225 if (ret) 226 return ret; 227 228 return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value); 229 } 230 231 static ssize_t lpss_ltr_mode_show(struct device *dev, 232 struct device_attribute *attr, char *buf) 233 { 234 u32 ltr_mode = 0; 235 char *outstr; 236 int ret; 237 238 ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode); 239 if (ret) 240 return ret; 241 242 outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto"; 243 return sprintf(buf, "%s\n", outstr); 244 } 245 246 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL); 247 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL); 248 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL); 249 250 static struct attribute *lpss_attrs[] = { 251 &dev_attr_auto_ltr.attr, 252 &dev_attr_sw_ltr.attr, 253 &dev_attr_ltr_mode.attr, 254 NULL, 255 }; 256 257 static struct attribute_group lpss_attr_group = { 258 .attrs = lpss_attrs, 259 .name = "lpss_ltr", 260 }; 261 262 static int acpi_lpss_platform_notify(struct notifier_block *nb, 263 unsigned long action, void *data) 264 { 265 struct platform_device *pdev = to_platform_device(data); 266 struct lpss_private_data *pdata; 267 struct acpi_device *adev; 268 const struct acpi_device_id *id; 269 int ret = 0; 270 271 id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev); 272 if (!id || !id->driver_data) 273 return 0; 274 275 if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev)) 276 return 0; 277 278 pdata = acpi_driver_data(adev); 279 if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required) 280 return 0; 281 282 if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) { 283 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n"); 284 return 0; 285 } 286 287 if (action == BUS_NOTIFY_ADD_DEVICE) 288 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group); 289 else if (action == BUS_NOTIFY_DEL_DEVICE) 290 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group); 291 292 return ret; 293 } 294 295 static struct notifier_block acpi_lpss_nb = { 296 .notifier_call = acpi_lpss_platform_notify, 297 }; 298 299 static struct acpi_scan_handler lpss_handler = { 300 .ids = acpi_lpss_device_ids, 301 .attach = acpi_lpss_create_device, 302 }; 303 304 void __init acpi_lpss_init(void) 305 { 306 if (!lpt_clk_init()) { 307 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb); 308 acpi_scan_add_handler(&lpss_handler); 309 } 310 } 311