[mirror_ubuntu-bionic-kernel.git] / drivers / acpi / acpi_lpss.c

/*
 * ACPI support for Intel Lynxpoint LPSS.
 *
 * Copyright (C) 2013, Intel Corporation
 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/platform_data/clk-lpss.h>
#include <linux/pm_runtime.h>

#include "internal.h"

ACPI_MODULE_NAME("acpi_lpss");

#define LPSS_CLK_SIZE	0x04
#define LPSS_LTR_SIZE	0x18

/* Offsets relative to LPSS_PRIVATE_OFFSET */
#define LPSS_GENERAL			0x08
#define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
#define LPSS_SW_LTR			0x10
#define LPSS_AUTO_LTR			0x14
#define LPSS_TX_INT			0x20
#define LPSS_TX_INT_MASK		BIT(1)

struct lpss_shared_clock {
	const char *name;
	unsigned long rate;
	struct clk *clk;
};

struct lpss_private_data;

struct lpss_device_desc {
	bool clk_required;
	const char *clkdev_name;
	bool ltr_required;
	unsigned int prv_offset;
	size_t prv_size_override;
	bool clk_gate;
	struct lpss_shared_clock *shared_clock;
	void (*setup)(struct lpss_private_data *pdata);
};

static struct lpss_device_desc lpss_dma_desc = {
	.clk_required = true,
	.clkdev_name = "hclk",
};

struct lpss_private_data {
	void __iomem *mmio_base;
	resource_size_t mmio_size;
	struct clk *clk;
	const struct lpss_device_desc *dev_desc;
};

static void lpss_uart_setup(struct lpss_private_data *pdata)
{
	unsigned int tx_int_offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
	u32 reg;

	reg = readl(pdata->mmio_base + tx_int_offset);
	writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + tx_int_offset);
}

static struct lpss_device_desc lpt_dev_desc = {
	.clk_required = true,
	.prv_offset = 0x800,
	.ltr_required = true,
	.clk_gate = true,
};

static struct lpss_device_desc lpt_uart_dev_desc = {
	.clk_required = true,
	.prv_offset = 0x800,
	.ltr_required = true,
	.clk_gate = true,
	.setup = lpss_uart_setup,
};

static struct lpss_device_desc lpt_sdio_dev_desc = {
	.prv_offset = 0x1000,
	.prv_size_override = 0x1018,
	.ltr_required = true,
};

static struct lpss_shared_clock uart_clock = {
	.name = "uart_clk",
	.rate = 44236800,
};

static struct lpss_device_desc byt_uart_dev_desc = {
	.clk_required = true,
	.prv_offset = 0x800,
	.clk_gate = true,
	.shared_clock = &uart_clock,
	.setup = lpss_uart_setup,
};

static struct lpss_shared_clock spi_clock = {
	.name = "spi_clk",
	.rate = 50000000,
};

static struct lpss_device_desc byt_spi_dev_desc = {
	.clk_required = true,
	.prv_offset = 0x400,
	.clk_gate = true,
	.shared_clock = &spi_clock,
};

static struct lpss_device_desc byt_sdio_dev_desc = {
	.clk_required = true,
};

static struct lpss_shared_clock i2c_clock = {
	.name = "i2c_clk",
	.rate = 100000000,
};

static struct lpss_device_desc byt_i2c_dev_desc = {
	.clk_required = true,
	.prv_offset = 0x800,
	.shared_clock = &i2c_clock,
};

static const struct acpi_device_id acpi_lpss_device_ids[] = {
	/* Generic LPSS devices */
	{ "INTL9C60", (unsigned long)&lpss_dma_desc },

	/* Lynxpoint LPSS devices */
	{ "INT33C0", (unsigned long)&lpt_dev_desc },
	{ "INT33C1", (unsigned long)&lpt_dev_desc },
	{ "INT33C2", (unsigned long)&lpt_dev_desc },
	{ "INT33C3", (unsigned long)&lpt_dev_desc },
	{ "INT33C4", (unsigned long)&lpt_uart_dev_desc },
	{ "INT33C5", (unsigned long)&lpt_uart_dev_desc },
	{ "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
	{ "INT33C7", },

	/* BayTrail LPSS devices */
	{ "80860F0A", (unsigned long)&byt_uart_dev_desc },
	{ "80860F0E", (unsigned long)&byt_spi_dev_desc },
	{ "80860F14", (unsigned long)&byt_sdio_dev_desc },
	{ "80860F41", (unsigned long)&byt_i2c_dev_desc },
	{ "INT33B2", },

	{ }
};

static int is_memory(struct acpi_resource *res, void *not_used)
{
	struct resource r;
	return !acpi_dev_resource_memory(res, &r);
}

/* LPSS main clock device. */
static struct platform_device *lpss_clk_dev;

static inline void lpt_register_clock_device(void)
{
	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
}

static int register_device_clock(struct acpi_device *adev,
				 struct lpss_private_data *pdata)
{
	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
	struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
	struct clk *clk = ERR_PTR(-ENODEV);
	struct lpss_clk_data *clk_data;
	const char *parent;

	if (!lpss_clk_dev)
		lpt_register_clock_device();

	clk_data = platform_get_drvdata(lpss_clk_dev);
	if (!clk_data)
		return -ENODEV;

	if (dev_desc->clkdev_name) {
		clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
				    dev_name(&adev->dev));
		return 0;
	}

	if (!pdata->mmio_base
	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
		return -ENODATA;

	parent = clk_data->name;

	if (shared_clock) {
		clk = shared_clock->clk;
		if (!clk) {
			clk = clk_register_fixed_rate(NULL, shared_clock->name,
						      "lpss_clk", 0,
						      shared_clock->rate);
			shared_clock->clk = clk;
		}
		parent = shared_clock->name;
	}

	if (dev_desc->clk_gate) {
		clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
					pdata->mmio_base + dev_desc->prv_offset,
					0, 0, NULL);
		pdata->clk = clk;
	}

	if (IS_ERR(clk))
		return PTR_ERR(clk);

	clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
	return 0;
}

static int acpi_lpss_create_device(struct acpi_device *adev,
				   const struct acpi_device_id *id)
{
	struct lpss_device_desc *dev_desc;
	struct lpss_private_data *pdata;
	struct resource_list_entry *rentry;
	struct list_head resource_list;
	int ret;

	dev_desc = (struct lpss_device_desc *)id->driver_data;
	if (!dev_desc)
		return acpi_create_platform_device(adev, id);

	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	INIT_LIST_HEAD(&resource_list);
	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
	if (ret < 0)
		goto err_out;

	list_for_each_entry(rentry, &resource_list, node)
		if (resource_type(&rentry->res) == IORESOURCE_MEM) {
			if (dev_desc->prv_size_override)
				pdata->mmio_size = dev_desc->prv_size_override;
			else
				pdata->mmio_size = resource_size(&rentry->res);
			pdata->mmio_base = ioremap(rentry->res.start,
						   pdata->mmio_size);
			break;
		}

	acpi_dev_free_resource_list(&resource_list);

	pdata->dev_desc = dev_desc;

	if (dev_desc->clk_required) {
		ret = register_device_clock(adev, pdata);
		if (ret) {
			/* Skip the device, but continue the namespace scan. */
			ret = 0;
			goto err_out;
		}
	}

	/*
	 * This works around a known issue in ACPI tables where LPSS devices
	 * have _PS0 and _PS3 without _PSC (and no power resources), so
	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
	 */
	ret = acpi_device_fix_up_power(adev);
	if (ret) {
		/* Skip the device, but continue the namespace scan. */
		ret = 0;
		goto err_out;
	}

	if (dev_desc->setup)
		dev_desc->setup(pdata);

	adev->driver_data = pdata;
	ret = acpi_create_platform_device(adev, id);
	if (ret > 0)
		return ret;

	adev->driver_data = NULL;

 err_out:
	kfree(pdata);
	return ret;
}

static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
{
	struct acpi_device *adev;
	struct lpss_private_data *pdata;
	unsigned long flags;
	int ret;

	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
	if (WARN_ON(ret))
		return ret;

	spin_lock_irqsave(&dev->power.lock, flags);
	if (pm_runtime_suspended(dev)) {
		ret = -EAGAIN;
		goto out;
	}
	pdata = acpi_driver_data(adev);
	if (WARN_ON(!pdata || !pdata->mmio_base)) {
		ret = -ENODEV;
		goto out;
	}
	*val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);

 out:
	spin_unlock_irqrestore(&dev->power.lock, flags);
	return ret;
}

static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	u32 ltr_value = 0;
	unsigned int reg;
	int ret;

	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
	ret = lpss_reg_read(dev, reg, &ltr_value);
	if (ret)
		return ret;

	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
}

static ssize_t lpss_ltr_mode_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	u32 ltr_mode = 0;
	char *outstr;
	int ret;

	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
	if (ret)
		return ret;

	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
	return sprintf(buf, "%s\n", outstr);
}

static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);

static struct attribute *lpss_attrs[] = {
	&dev_attr_auto_ltr.attr,
	&dev_attr_sw_ltr.attr,
	&dev_attr_ltr_mode.attr,
	NULL,
};

static struct attribute_group lpss_attr_group = {
	.attrs = lpss_attrs,
	.name = "lpss_ltr",
};

static int acpi_lpss_platform_notify(struct notifier_block *nb,
				     unsigned long action, void *data)
{
	struct platform_device *pdev = to_platform_device(data);
	struct lpss_private_data *pdata;
	struct acpi_device *adev;
	const struct acpi_device_id *id;
	int ret = 0;

	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
	if (!id || !id->driver_data)
		return 0;

	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
		return 0;

	pdata = acpi_driver_data(adev);
	if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
		return 0;

	if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
		return 0;
	}

	if (action == BUS_NOTIFY_ADD_DEVICE)
		ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
	else if (action == BUS_NOTIFY_DEL_DEVICE)
		sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);

	return ret;
}

static struct notifier_block acpi_lpss_nb = {
	.notifier_call = acpi_lpss_platform_notify,
};

static struct acpi_scan_handler lpss_handler = {
	.ids = acpi_lpss_device_ids,
	.attach = acpi_lpss_create_device,
};

void __init acpi_lpss_init(void)
{
	if (!lpt_clk_init()) {
		bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
		acpi_scan_add_handler(&lpss_handler);
	}
}
Commit	Line	Data
f58b082a RW	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>
2e0f8822	21	#include <linux/pm_runtime.h>
f58b082a RW	22
	23	#include "internal.h"
	24
	25	ACPI_MODULE_NAME("acpi_lpss");
	26
f58b082a	27	#define LPSS_CLK_SIZE 0x04
2e0f8822 RW	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
06d86415 HK	35	#define LPSS_TX_INT 0x20
06d86415 HK	36	#define LPSS_TX_INT_MASK BIT(1)
f58b082a	37
f6272170 MW	38	struct lpss_shared_clock {
	39	const char *name;
	40	unsigned long rate;
	41	struct clk *clk;
	42	};
	43
06d86415	44	struct lpss_private_data;
f58b082a RW	45
	46	struct lpss_device_desc {
	47	bool clk_required;
b59cc200	48	const char *clkdev_name;
2e0f8822 RW	49	bool ltr_required;
2e0f8822 RW	50	unsigned int prv_offset;
958c4eb2	51	size_t prv_size_override;
f6272170 MW	52	bool clk_gate;
f6272170 MW	53	struct lpss_shared_clock *shared_clock;
06d86415	54	void (setup)(struct lpss_private_data pdata);
f58b082a RW	55	};
f58b082a RW	56
b59cc200 RW	57	static struct lpss_device_desc lpss_dma_desc = {
	58	.clk_required = true,
	59	.clkdev_name = "hclk",
	60	};
	61
f58b082a RW	62	struct lpss_private_data {
	63	void __iomem *mmio_base;
	64	resource_size_t mmio_size;
	65	struct clk *clk;
	66	const struct lpss_device_desc *dev_desc;
	67	};
	68
06d86415 HK	69	static void lpss_uart_setup(struct lpss_private_data *pdata)
	70	{
	71	unsigned int tx_int_offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
	72	u32 reg;
	73
	74	reg = readl(pdata->mmio_base + tx_int_offset);
	75	writel(reg \| LPSS_TX_INT_MASK, pdata->mmio_base + tx_int_offset);
	76	}
	77
f58b082a RW	78	static struct lpss_device_desc lpt_dev_desc = {
f58b082a RW	79	.clk_required = true,
2e0f8822 RW	80	.prv_offset = 0x800,
2e0f8822 RW	81	.ltr_required = true,
f6272170	82	.clk_gate = true,
2e0f8822 RW	83	};
2e0f8822 RW	84
06d86415 HK	85	static struct lpss_device_desc lpt_uart_dev_desc = {
	86	.clk_required = true,
	87	.prv_offset = 0x800,
	88	.ltr_required = true,
	89	.clk_gate = true,
	90	.setup = lpss_uart_setup,
2e0f8822 RW	91	};
	92
	93	static struct lpss_device_desc lpt_sdio_dev_desc = {
	94	.prv_offset = 0x1000,
958c4eb2	95	.prv_size_override = 0x1018,
2e0f8822	96	.ltr_required = true,
f58b082a RW	97	};
f58b082a RW	98
f6272170 MW	99	static struct lpss_shared_clock uart_clock = {
	100	.name = "uart_clk",
	101	.rate = 44236800,
	102	};
	103
	104	static struct lpss_device_desc byt_uart_dev_desc = {
	105	.clk_required = true,
	106	.prv_offset = 0x800,
	107	.clk_gate = true,
	108	.shared_clock = &uart_clock,
06d86415	109	.setup = lpss_uart_setup,
f6272170 MW	110	};
	111
	112	static struct lpss_shared_clock spi_clock = {
	113	.name = "spi_clk",
	114	.rate = 50000000,
	115	};
	116
	117	static struct lpss_device_desc byt_spi_dev_desc = {
	118	.clk_required = true,
	119	.prv_offset = 0x400,
	120	.clk_gate = true,
	121	.shared_clock = &spi_clock,
	122	};
	123
	124	static struct lpss_device_desc byt_sdio_dev_desc = {
	125	.clk_required = true,
	126	};
	127
	128	static struct lpss_shared_clock i2c_clock = {
	129	.name = "i2c_clk",
	130	.rate = 100000000,
	131	};
	132
	133	static struct lpss_device_desc byt_i2c_dev_desc = {
	134	.clk_required = true,
	135	.prv_offset = 0x800,
	136	.shared_clock = &i2c_clock,
	137	};
	138
f58b082a	139	static const struct acpi_device_id acpi_lpss_device_ids[] = {
b59cc200 RW	140	/* Generic LPSS devices */
	141	{ "INTL9C60", (unsigned long)&lpss_dma_desc },
	142
f58b082a RW	143	/* Lynxpoint LPSS devices */
	144	{ "INT33C0", (unsigned long)&lpt_dev_desc },
	145	{ "INT33C1", (unsigned long)&lpt_dev_desc },
	146	{ "INT33C2", (unsigned long)&lpt_dev_desc },
	147	{ "INT33C3", (unsigned long)&lpt_dev_desc },
06d86415 HK	148	{ "INT33C4", (unsigned long)&lpt_uart_dev_desc },
06d86415 HK	149	{ "INT33C5", (unsigned long)&lpt_uart_dev_desc },
2e0f8822	150	{ "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
f58b082a RW	151	{ "INT33C7", },
f58b082a RW	152
f6272170 MW	153	/* BayTrail LPSS devices */
	154	{ "80860F0A", (unsigned long)&byt_uart_dev_desc },
	155	{ "80860F0E", (unsigned long)&byt_spi_dev_desc },
	156	{ "80860F14", (unsigned long)&byt_sdio_dev_desc },
	157	{ "80860F41", (unsigned long)&byt_i2c_dev_desc },
	158	{ "INT33B2", },
	159
f58b082a RW	160	{ }
	161	};
	162
	163	static int is_memory(struct acpi_resource res, void not_used)
	164	{
	165	struct resource r;
	166	return !acpi_dev_resource_memory(res, &r);
	167	}
	168
	169	/* LPSS main clock device. */
	170	static struct platform_device *lpss_clk_dev;
	171
	172	static inline void lpt_register_clock_device(void)
	173	{
	174	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
	175	}
	176
	177	static int register_device_clock(struct acpi_device *adev,
	178	struct lpss_private_data *pdata)
	179	{
	180	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
f6272170 MW	181	struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
f6272170 MW	182	struct clk *clk = ERR_PTR(-ENODEV);
b59cc200	183	struct lpss_clk_data *clk_data;
f6272170	184	const char *parent;
f58b082a RW	185
	186	if (!lpss_clk_dev)
	187	lpt_register_clock_device();
	188
b59cc200 RW	189	clk_data = platform_get_drvdata(lpss_clk_dev);
	190	if (!clk_data)
	191	return -ENODEV;
	192
	193	if (dev_desc->clkdev_name) {
	194	clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
	195	dev_name(&adev->dev));
	196	return 0;
	197	}
	198
	199	if (!pdata->mmio_base
2e0f8822	200	\|\| pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
f58b082a RW	201	return -ENODATA;
f58b082a RW	202
f6272170 MW	203	parent = clk_data->name;
	204
	205	if (shared_clock) {
	206	clk = shared_clock->clk;
	207	if (!clk) {
	208	clk = clk_register_fixed_rate(NULL, shared_clock->name,
	209	"lpss_clk", 0,
	210	shared_clock->rate);
	211	shared_clock->clk = clk;
	212	}
	213	parent = shared_clock->name;
	214	}
	215
	216	if (dev_desc->clk_gate) {
	217	clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
	218	pdata->mmio_base + dev_desc->prv_offset,
	219	0, 0, NULL);
	220	pdata->clk = clk;
	221	}
f58b082a	222
f6272170 MW	223	if (IS_ERR(clk))
f6272170 MW	224	return PTR_ERR(clk);
f58b082a	225
f6272170	226	clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
f58b082a RW	227	return 0;
	228	}
	229
	230	static int acpi_lpss_create_device(struct acpi_device *adev,
	231	const struct acpi_device_id *id)
	232	{
	233	struct lpss_device_desc *dev_desc;
	234	struct lpss_private_data *pdata;
	235	struct resource_list_entry *rentry;
	236	struct list_head resource_list;
	237	int ret;
	238
	239	dev_desc = (struct lpss_device_desc *)id->driver_data;
	240	if (!dev_desc)
	241	return acpi_create_platform_device(adev, id);
	242
	243	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	244	if (!pdata)
	245	return -ENOMEM;
	246
	247	INIT_LIST_HEAD(&resource_list);
	248	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
	249	if (ret < 0)
	250	goto err_out;
	251
	252	list_for_each_entry(rentry, &resource_list, node)
	253	if (resource_type(&rentry->res) == IORESOURCE_MEM) {
958c4eb2 MW	254	if (dev_desc->prv_size_override)
	255	pdata->mmio_size = dev_desc->prv_size_override;
	256	else
	257	pdata->mmio_size = resource_size(&rentry->res);
f58b082a RW	258	pdata->mmio_base = ioremap(rentry->res.start,
f58b082a RW	259	pdata->mmio_size);
f58b082a RW	260	break;
	261	}
	262
	263	acpi_dev_free_resource_list(&resource_list);
	264
af65cfe9 MW	265	pdata->dev_desc = dev_desc;
af65cfe9 MW	266
f58b082a RW	267	if (dev_desc->clk_required) {
	268	ret = register_device_clock(adev, pdata);
	269	if (ret) {
b9e95fc6 RW	270	/* Skip the device, but continue the namespace scan. */
	271	ret = 0;
	272	goto err_out;
f58b082a RW	273	}
	274	}
	275
b9e95fc6 RW	276	/*
	277	* This works around a known issue in ACPI tables where LPSS devices
	278	* have _PS0 and _PS3 without _PSC (and no power resources), so
	279	* acpi_bus_init_power() will assume that the BIOS has put them into D0.
	280	*/
	281	ret = acpi_device_fix_up_power(adev);
	282	if (ret) {
	283	/* Skip the device, but continue the namespace scan. */
	284	ret = 0;
	285	goto err_out;
	286	}
	287
06d86415 HK	288	if (dev_desc->setup)
	289	dev_desc->setup(pdata);
	290
f58b082a RW	291	adev->driver_data = pdata;
	292	ret = acpi_create_platform_device(adev, id);
	293	if (ret > 0)
	294	return ret;
	295
	296	adev->driver_data = NULL;
	297
	298	err_out:
	299	kfree(pdata);
	300	return ret;
	301	}
	302
2e0f8822 RW	303	static int lpss_reg_read(struct device dev, unsigned int reg, u32 val)
	304	{
	305	struct acpi_device *adev;
	306	struct lpss_private_data *pdata;
	307	unsigned long flags;
	308	int ret;
	309
	310	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
	311	if (WARN_ON(ret))
	312	return ret;
	313
	314	spin_lock_irqsave(&dev->power.lock, flags);
	315	if (pm_runtime_suspended(dev)) {
	316	ret = -EAGAIN;
	317	goto out;
	318	}
	319	pdata = acpi_driver_data(adev);
	320	if (WARN_ON(!pdata \|\| !pdata->mmio_base)) {
	321	ret = -ENODEV;
	322	goto out;
	323	}
	324	*val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
	325
	326	out:
	327	spin_unlock_irqrestore(&dev->power.lock, flags);
	328	return ret;
	329	}
	330
	331	static ssize_t lpss_ltr_show(struct device dev, struct device_attribute attr,
	332	char *buf)
	333	{
	334	u32 ltr_value = 0;
	335	unsigned int reg;
	336	int ret;
	337
	338	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
	339	ret = lpss_reg_read(dev, reg, &ltr_value);
	340	if (ret)
	341	return ret;
	342
	343	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
	344	}
	345
	346	static ssize_t lpss_ltr_mode_show(struct device *dev,
	347	struct device_attribute attr, char buf)
	348	{
	349	u32 ltr_mode = 0;
	350	char *outstr;
	351	int ret;
	352
	353	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
	354	if (ret)
	355	return ret;
	356
	357	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
	358	return sprintf(buf, "%s\n", outstr);
	359	}
	360
	361	static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
	362	static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
	363	static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
	364
	365	static struct attribute *lpss_attrs[] = {
	366	&dev_attr_auto_ltr.attr,
367	&dev_attr_sw_ltr.attr,
368	&dev_attr_ltr_mode.attr,
369	NULL,
370	};
371
372	static struct attribute_group lpss_attr_group = {
373	.attrs = lpss_attrs,
374	.name = "lpss_ltr",
375	};
376
377	static int acpi_lpss_platform_notify(struct notifier_block *nb,
378	unsigned long action, void *data)
379	{
380	struct platform_device *pdev = to_platform_device(data);
381	struct lpss_private_data *pdata;
382	struct acpi_device *adev;
383	const struct acpi_device_id *id;
384	int ret = 0;
385
386	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
387	if (!id \|\| !id->driver_data)
388	return 0;
389
390	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
391	return 0;
392
393	pdata = acpi_driver_data(adev);
394	if (!pdata \|\| !pdata->mmio_base \|\| !pdata->dev_desc->ltr_required)
395	return 0;
396
397	if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
398	dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
399	return 0;
400	}
401
402	if (action == BUS_NOTIFY_ADD_DEVICE)
403	ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
404	else if (action == BUS_NOTIFY_DEL_DEVICE)
405	sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
406
407	return ret;
408	}
409
410	static struct notifier_block acpi_lpss_nb = {
411	.notifier_call = acpi_lpss_platform_notify,
412	};
413
f58b082a RW	414	static struct acpi_scan_handler lpss_handler = {
	415	.ids = acpi_lpss_device_ids,
	416	.attach = acpi_lpss_create_device,
	417	};
	418
	419	void __init acpi_lpss_init(void)
	420	{
2e0f8822 RW	421	if (!lpt_clk_init()) {
2e0f8822 RW	422	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
f58b082a	423	acpi_scan_add_handler(&lpss_handler);
2e0f8822	424	}
f58b082a	425	}