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, <r_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, <r_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 } 293