2 * ACPI support for Intel Lynxpoint LPSS.
4 * Copyright (C) 2013, Intel Corporation
5 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
6 * Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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.
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>
19 #include <linux/platform_device.h>
20 #include <linux/platform_data/clk-lpss.h>
21 #include <linux/pm_runtime.h>
25 ACPI_MODULE_NAME("acpi_lpss");
27 #define LPSS_CLK_SIZE 0x04
28 #define LPSS_LTR_SIZE 0x18
30 /* Offsets relative to LPSS_PRIVATE_OFFSET */
31 #define LPSS_GENERAL 0x08
32 #define LPSS_GENERAL_LTR_MODE_SW BIT(2)
33 #define LPSS_GENERAL_UART_RTS_OVRD BIT(3)
34 #define LPSS_SW_LTR 0x10
35 #define LPSS_AUTO_LTR 0x14
36 #define LPSS_TX_INT 0x20
37 #define LPSS_TX_INT_MASK BIT(1)
39 struct lpss_shared_clock {
45 struct lpss_private_data;
47 struct lpss_device_desc {
49 const char *clkdev_name;
51 unsigned int prv_offset;
52 size_t prv_size_override;
54 struct lpss_shared_clock *shared_clock;
55 void (*setup)(struct lpss_private_data *pdata);
58 static struct lpss_device_desc lpss_dma_desc = {
60 .clkdev_name = "hclk",
63 struct lpss_private_data {
64 void __iomem *mmio_base;
65 resource_size_t mmio_size;
67 const struct lpss_device_desc *dev_desc;
70 static void lpss_uart_setup(struct lpss_private_data *pdata)
75 offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
76 reg = readl(pdata->mmio_base + offset);
77 writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
79 offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
80 reg = readl(pdata->mmio_base + offset);
81 writel(reg | LPSS_GENERAL_UART_RTS_OVRD, pdata->mmio_base + offset);
84 static struct lpss_device_desc lpt_dev_desc = {
91 static struct lpss_device_desc lpt_uart_dev_desc = {
96 .setup = lpss_uart_setup,
99 static struct lpss_device_desc lpt_sdio_dev_desc = {
100 .prv_offset = 0x1000,
101 .prv_size_override = 0x1018,
102 .ltr_required = true,
105 static struct lpss_shared_clock uart_clock = {
110 static struct lpss_device_desc byt_uart_dev_desc = {
111 .clk_required = true,
114 .shared_clock = &uart_clock,
115 .setup = lpss_uart_setup,
118 static struct lpss_shared_clock spi_clock = {
123 static struct lpss_device_desc byt_spi_dev_desc = {
124 .clk_required = true,
127 .shared_clock = &spi_clock,
130 static struct lpss_device_desc byt_sdio_dev_desc = {
131 .clk_required = true,
134 static struct lpss_shared_clock i2c_clock = {
139 static struct lpss_device_desc byt_i2c_dev_desc = {
140 .clk_required = true,
142 .shared_clock = &i2c_clock,
145 static const struct acpi_device_id acpi_lpss_device_ids[] = {
146 /* Generic LPSS devices */
147 { "INTL9C60", (unsigned long)&lpss_dma_desc },
149 /* Lynxpoint LPSS devices */
150 { "INT33C0", (unsigned long)&lpt_dev_desc },
151 { "INT33C1", (unsigned long)&lpt_dev_desc },
152 { "INT33C2", (unsigned long)&lpt_dev_desc },
153 { "INT33C3", (unsigned long)&lpt_dev_desc },
154 { "INT33C4", (unsigned long)&lpt_uart_dev_desc },
155 { "INT33C5", (unsigned long)&lpt_uart_dev_desc },
156 { "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
159 /* BayTrail LPSS devices */
160 { "80860F0A", (unsigned long)&byt_uart_dev_desc },
161 { "80860F0E", (unsigned long)&byt_spi_dev_desc },
162 { "80860F14", (unsigned long)&byt_sdio_dev_desc },
163 { "80860F41", (unsigned long)&byt_i2c_dev_desc },
169 static int is_memory(struct acpi_resource *res, void *not_used)
172 return !acpi_dev_resource_memory(res, &r);
175 /* LPSS main clock device. */
176 static struct platform_device *lpss_clk_dev;
178 static inline void lpt_register_clock_device(void)
180 lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
183 static int register_device_clock(struct acpi_device *adev,
184 struct lpss_private_data *pdata)
186 const struct lpss_device_desc *dev_desc = pdata->dev_desc;
187 struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
188 struct clk *clk = ERR_PTR(-ENODEV);
189 struct lpss_clk_data *clk_data;
193 lpt_register_clock_device();
195 clk_data = platform_get_drvdata(lpss_clk_dev);
199 if (dev_desc->clkdev_name) {
200 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
201 dev_name(&adev->dev));
205 if (!pdata->mmio_base
206 || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
209 parent = clk_data->name;
212 clk = shared_clock->clk;
214 clk = clk_register_fixed_rate(NULL, shared_clock->name,
217 shared_clock->clk = clk;
219 parent = shared_clock->name;
222 if (dev_desc->clk_gate) {
223 clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
224 pdata->mmio_base + dev_desc->prv_offset,
232 clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
236 static int acpi_lpss_create_device(struct acpi_device *adev,
237 const struct acpi_device_id *id)
239 struct lpss_device_desc *dev_desc;
240 struct lpss_private_data *pdata;
241 struct resource_list_entry *rentry;
242 struct list_head resource_list;
245 dev_desc = (struct lpss_device_desc *)id->driver_data;
247 return acpi_create_platform_device(adev, id);
249 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
253 INIT_LIST_HEAD(&resource_list);
254 ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
258 list_for_each_entry(rentry, &resource_list, node)
259 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
260 if (dev_desc->prv_size_override)
261 pdata->mmio_size = dev_desc->prv_size_override;
263 pdata->mmio_size = resource_size(&rentry->res);
264 pdata->mmio_base = ioremap(rentry->res.start,
269 acpi_dev_free_resource_list(&resource_list);
271 pdata->dev_desc = dev_desc;
273 if (dev_desc->clk_required) {
274 ret = register_device_clock(adev, pdata);
276 /* Skip the device, but continue the namespace scan. */
283 * This works around a known issue in ACPI tables where LPSS devices
284 * have _PS0 and _PS3 without _PSC (and no power resources), so
285 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
287 ret = acpi_device_fix_up_power(adev);
289 /* Skip the device, but continue the namespace scan. */
295 dev_desc->setup(pdata);
297 adev->driver_data = pdata;
298 ret = acpi_create_platform_device(adev, id);
302 adev->driver_data = NULL;
309 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
311 struct acpi_device *adev;
312 struct lpss_private_data *pdata;
316 ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
320 spin_lock_irqsave(&dev->power.lock, flags);
321 if (pm_runtime_suspended(dev)) {
325 pdata = acpi_driver_data(adev);
326 if (WARN_ON(!pdata || !pdata->mmio_base)) {
330 *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
333 spin_unlock_irqrestore(&dev->power.lock, flags);
337 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
344 reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
345 ret = lpss_reg_read(dev, reg, <r_value);
349 return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
352 static ssize_t lpss_ltr_mode_show(struct device *dev,
353 struct device_attribute *attr, char *buf)
359 ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode);
363 outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
364 return sprintf(buf, "%s\n", outstr);
367 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
368 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
369 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
371 static struct attribute *lpss_attrs[] = {
372 &dev_attr_auto_ltr.attr,
373 &dev_attr_sw_ltr.attr,
374 &dev_attr_ltr_mode.attr,
378 static struct attribute_group lpss_attr_group = {
383 static int acpi_lpss_platform_notify(struct notifier_block *nb,
384 unsigned long action, void *data)
386 struct platform_device *pdev = to_platform_device(data);
387 struct lpss_private_data *pdata;
388 struct acpi_device *adev;
389 const struct acpi_device_id *id;
392 id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
393 if (!id || !id->driver_data)
396 if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
399 pdata = acpi_driver_data(adev);
400 if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
403 if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
404 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
408 if (action == BUS_NOTIFY_ADD_DEVICE)
409 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
410 else if (action == BUS_NOTIFY_DEL_DEVICE)
411 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
416 static struct notifier_block acpi_lpss_nb = {
417 .notifier_call = acpi_lpss_platform_notify,
420 static struct acpi_scan_handler lpss_handler = {
421 .ids = acpi_lpss_device_ids,
422 .attach = acpi_lpss_create_device,
425 void __init acpi_lpss_init(void)
427 if (!lpt_clk_init()) {
428 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
429 acpi_scan_add_handler(&lpss_handler);