Linux Audio

Check our new training course

Loading...
v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Intel MID Power Management Unit (PWRMU) device driver
  4 *
  5 * Copyright (C) 2016, Intel Corporation
  6 *
  7 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 
 
 
 
  8 *
  9 * Intel MID Power Management Unit device driver handles the South Complex PCI
 10 * devices such as GPDMA, SPI, I2C, PWM, and so on. By default PCI core
 11 * modifies bits in PMCSR register in the PCI configuration space. This is not
 12 * enough on some SoCs like Intel Tangier. In such case PCI core sets a new
 13 * power state of the device in question through a PM hook registered in struct
 14 * pci_platform_pm_ops (see drivers/pci/pci-mid.c).
 15 */
 16
 17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 18
 19#include <linux/delay.h>
 20#include <linux/errno.h>
 21#include <linux/interrupt.h>
 22#include <linux/kernel.h>
 23#include <linux/export.h>
 24#include <linux/mutex.h>
 25#include <linux/pci.h>
 26
 27#include <asm/intel-mid.h>
 28
 29/* Registers */
 30#define PM_STS			0x00
 31#define PM_CMD			0x04
 32#define PM_ICS			0x08
 33#define PM_WKC(x)		(0x10 + (x) * 4)
 34#define PM_WKS(x)		(0x18 + (x) * 4)
 35#define PM_SSC(x)		(0x20 + (x) * 4)
 36#define PM_SSS(x)		(0x30 + (x) * 4)
 37
 38/* Bits in PM_STS */
 39#define PM_STS_BUSY		(1 << 8)
 40
 41/* Bits in PM_CMD */
 42#define PM_CMD_CMD(x)		((x) << 0)
 43#define PM_CMD_IOC		(1 << 8)
 44#define PM_CMD_CM_NOP		(0 << 9)
 45#define PM_CMD_CM_IMMEDIATE	(1 << 9)
 46#define PM_CMD_CM_DELAY		(2 << 9)
 47#define PM_CMD_CM_TRIGGER	(3 << 9)
 48
 49/* System states */
 50#define PM_CMD_SYS_STATE_S5	(5 << 16)
 51
 52/* Trigger variants */
 53#define PM_CMD_CFG_TRIGGER_NC	(3 << 19)
 54
 55/* Message to wait for TRIGGER_NC case */
 56#define TRIGGER_NC_MSG_2	(2 << 22)
 57
 58/* List of commands */
 59#define CMD_SET_CFG		0x01
 60
 61/* Bits in PM_ICS */
 62#define PM_ICS_INT_STATUS(x)	((x) & 0xff)
 63#define PM_ICS_IE		(1 << 8)
 64#define PM_ICS_IP		(1 << 9)
 65#define PM_ICS_SW_INT_STS	(1 << 10)
 66
 67/* List of interrupts */
 68#define INT_INVALID		0
 69#define INT_CMD_COMPLETE	1
 70#define INT_CMD_ERR		2
 71#define INT_WAKE_EVENT		3
 72#define INT_LSS_POWER_ERR	4
 73#define INT_S0iX_MSG_ERR	5
 74#define INT_NO_C6		6
 75#define INT_TRIGGER_ERR		7
 76#define INT_INACTIVITY		8
 77
 78/* South Complex devices */
 79#define LSS_MAX_SHARED_DEVS	4
 80#define LSS_MAX_DEVS		64
 81
 82#define LSS_WS_BITS		1	/* wake state width */
 83#define LSS_PWS_BITS		2	/* power state width */
 84
 85/* Supported device IDs */
 86#define PCI_DEVICE_ID_PENWELL	0x0828
 87#define PCI_DEVICE_ID_TANGIER	0x11a1
 88
 89struct mid_pwr_dev {
 90	struct pci_dev *pdev;
 91	pci_power_t state;
 92};
 93
 94struct mid_pwr {
 95	struct device *dev;
 96	void __iomem *regs;
 97	int irq;
 98	bool available;
 99
100	struct mutex lock;
101	struct mid_pwr_dev lss[LSS_MAX_DEVS][LSS_MAX_SHARED_DEVS];
102};
103
104static struct mid_pwr *midpwr;
105
106static u32 mid_pwr_get_state(struct mid_pwr *pwr, int reg)
107{
108	return readl(pwr->regs + PM_SSS(reg));
109}
110
111static void mid_pwr_set_state(struct mid_pwr *pwr, int reg, u32 value)
112{
113	writel(value, pwr->regs + PM_SSC(reg));
114}
115
116static void mid_pwr_set_wake(struct mid_pwr *pwr, int reg, u32 value)
117{
118	writel(value, pwr->regs + PM_WKC(reg));
119}
120
121static void mid_pwr_interrupt_disable(struct mid_pwr *pwr)
122{
123	writel(~PM_ICS_IE, pwr->regs + PM_ICS);
124}
125
126static bool mid_pwr_is_busy(struct mid_pwr *pwr)
127{
128	return !!(readl(pwr->regs + PM_STS) & PM_STS_BUSY);
129}
130
131/* Wait 500ms that the latest PWRMU command finished */
132static int mid_pwr_wait(struct mid_pwr *pwr)
133{
134	unsigned int count = 500000;
135	bool busy;
136
137	do {
138		busy = mid_pwr_is_busy(pwr);
139		if (!busy)
140			return 0;
141		udelay(1);
142	} while (--count);
143
144	return -EBUSY;
145}
146
147static int mid_pwr_wait_for_cmd(struct mid_pwr *pwr, u8 cmd)
148{
149	writel(PM_CMD_CMD(cmd) | PM_CMD_CM_IMMEDIATE, pwr->regs + PM_CMD);
150	return mid_pwr_wait(pwr);
151}
152
153static int __update_power_state(struct mid_pwr *pwr, int reg, int bit, int new)
154{
155	int curstate;
156	u32 power;
157	int ret;
158
159	/* Check if the device is already in desired state */
160	power = mid_pwr_get_state(pwr, reg);
161	curstate = (power >> bit) & 3;
162	if (curstate == new)
163		return 0;
164
165	/* Update the power state */
166	mid_pwr_set_state(pwr, reg, (power & ~(3 << bit)) | (new << bit));
167
168	/* Send command to SCU */
169	ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG);
170	if (ret)
171		return ret;
172
173	/* Check if the device is already in desired state */
174	power = mid_pwr_get_state(pwr, reg);
175	curstate = (power >> bit) & 3;
176	if (curstate != new)
177		return -EAGAIN;
178
179	return 0;
180}
181
182static pci_power_t __find_weakest_power_state(struct mid_pwr_dev *lss,
183					      struct pci_dev *pdev,
184					      pci_power_t state)
185{
186	pci_power_t weakest = PCI_D3hot;
187	unsigned int j;
188
189	/* Find device in cache or first free cell */
190	for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) {
191		if (lss[j].pdev == pdev || !lss[j].pdev)
192			break;
193	}
194
195	/* Store the desired state in cache */
196	if (j < LSS_MAX_SHARED_DEVS) {
197		lss[j].pdev = pdev;
198		lss[j].state = state;
199	} else {
200		dev_WARN(&pdev->dev, "No room for device in PWRMU LSS cache\n");
201		weakest = state;
202	}
203
204	/* Find the power state we may use */
205	for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) {
206		if (lss[j].state < weakest)
207			weakest = lss[j].state;
208	}
209
210	return weakest;
211}
212
213static int __set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev,
214			     pci_power_t state, int id, int reg, int bit)
215{
216	const char *name;
217	int ret;
218
219	state = __find_weakest_power_state(pwr->lss[id], pdev, state);
220	name = pci_power_name(state);
221
222	ret = __update_power_state(pwr, reg, bit, (__force int)state);
223	if (ret) {
224		dev_warn(&pdev->dev, "Can't set power state %s: %d\n", name, ret);
225		return ret;
226	}
227
228	dev_vdbg(&pdev->dev, "Set power state %s\n", name);
229	return 0;
230}
231
232static int mid_pwr_set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev,
233				   pci_power_t state)
234{
235	int id, reg, bit;
236	int ret;
237
238	id = intel_mid_pwr_get_lss_id(pdev);
239	if (id < 0)
240		return id;
241
242	reg = (id * LSS_PWS_BITS) / 32;
243	bit = (id * LSS_PWS_BITS) % 32;
244
245	/* We support states between PCI_D0 and PCI_D3hot */
246	if (state < PCI_D0)
247		state = PCI_D0;
248	if (state > PCI_D3hot)
249		state = PCI_D3hot;
250
251	mutex_lock(&pwr->lock);
252	ret = __set_power_state(pwr, pdev, state, id, reg, bit);
253	mutex_unlock(&pwr->lock);
254	return ret;
255}
256
257int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state)
258{
259	struct mid_pwr *pwr = midpwr;
260	int ret = 0;
261
262	might_sleep();
263
264	if (pwr && pwr->available)
265		ret = mid_pwr_set_power_state(pwr, pdev, state);
266	dev_vdbg(&pdev->dev, "set_power_state() returns %d\n", ret);
267
268	return 0;
269}
270
271pci_power_t intel_mid_pci_get_power_state(struct pci_dev *pdev)
272{
273	struct mid_pwr *pwr = midpwr;
274	int id, reg, bit;
275	u32 power;
276
277	if (!pwr || !pwr->available)
278		return PCI_UNKNOWN;
279
280	id = intel_mid_pwr_get_lss_id(pdev);
281	if (id < 0)
282		return PCI_UNKNOWN;
283
284	reg = (id * LSS_PWS_BITS) / 32;
285	bit = (id * LSS_PWS_BITS) % 32;
286	power = mid_pwr_get_state(pwr, reg);
287	return (__force pci_power_t)((power >> bit) & 3);
288}
289
290void intel_mid_pwr_power_off(void)
291{
292	struct mid_pwr *pwr = midpwr;
293	u32 cmd = PM_CMD_SYS_STATE_S5 |
294		  PM_CMD_CMD(CMD_SET_CFG) |
295		  PM_CMD_CM_TRIGGER |
296		  PM_CMD_CFG_TRIGGER_NC |
297		  TRIGGER_NC_MSG_2;
298
299	/* Send command to SCU */
300	writel(cmd, pwr->regs + PM_CMD);
301	mid_pwr_wait(pwr);
302}
303
304int intel_mid_pwr_get_lss_id(struct pci_dev *pdev)
305{
306	int vndr;
307	u8 id;
308
309	/*
310	 * Mapping to PWRMU index is kept in the Logical SubSystem ID byte of
311	 * Vendor capability.
312	 */
313	vndr = pci_find_capability(pdev, PCI_CAP_ID_VNDR);
314	if (!vndr)
315		return -EINVAL;
316
317	/* Read the Logical SubSystem ID byte */
318	pci_read_config_byte(pdev, vndr + INTEL_MID_PWR_LSS_OFFSET, &id);
319	if (!(id & INTEL_MID_PWR_LSS_TYPE))
320		return -ENODEV;
321
322	id &= ~INTEL_MID_PWR_LSS_TYPE;
323	if (id >= LSS_MAX_DEVS)
324		return -ERANGE;
325
326	return id;
327}
328
329static irqreturn_t mid_pwr_irq_handler(int irq, void *dev_id)
330{
331	struct mid_pwr *pwr = dev_id;
332	u32 ics;
333
334	ics = readl(pwr->regs + PM_ICS);
335	if (!(ics & PM_ICS_IP))
336		return IRQ_NONE;
337
338	writel(ics | PM_ICS_IP, pwr->regs + PM_ICS);
339
340	dev_warn(pwr->dev, "Unexpected IRQ: %#x\n", PM_ICS_INT_STATUS(ics));
341	return IRQ_HANDLED;
342}
343
344struct mid_pwr_device_info {
345	int (*set_initial_state)(struct mid_pwr *pwr);
346};
347
348static int mid_pwr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
349{
350	struct mid_pwr_device_info *info = (void *)id->driver_data;
351	struct device *dev = &pdev->dev;
352	struct mid_pwr *pwr;
353	int ret;
354
355	ret = pcim_enable_device(pdev);
356	if (ret < 0) {
357		dev_err(&pdev->dev, "error: could not enable device\n");
358		return ret;
359	}
360
361	ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
362	if (ret) {
363		dev_err(&pdev->dev, "I/O memory remapping failed\n");
364		return ret;
365	}
366
367	pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL);
368	if (!pwr)
369		return -ENOMEM;
370
371	pwr->dev = dev;
372	pwr->regs = pcim_iomap_table(pdev)[0];
373	pwr->irq = pdev->irq;
374
375	mutex_init(&pwr->lock);
376
377	/* Disable interrupts */
378	mid_pwr_interrupt_disable(pwr);
379
380	if (info && info->set_initial_state) {
381		ret = info->set_initial_state(pwr);
382		if (ret)
383			dev_warn(dev, "Can't set initial state: %d\n", ret);
384	}
385
386	ret = devm_request_irq(dev, pdev->irq, mid_pwr_irq_handler,
387			       IRQF_NO_SUSPEND, pci_name(pdev), pwr);
388	if (ret)
389		return ret;
390
391	pwr->available = true;
392	midpwr = pwr;
393
394	pci_set_drvdata(pdev, pwr);
395	return 0;
396}
397
398static int mid_set_initial_state(struct mid_pwr *pwr, const u32 *states)
399{
400	unsigned int i, j;
401	int ret;
402
403	/*
404	 * Enable wake events.
405	 *
406	 * PWRMU supports up to 32 sources for wake up the system. Ungate them
407	 * all here.
408	 */
409	mid_pwr_set_wake(pwr, 0, 0xffffffff);
410	mid_pwr_set_wake(pwr, 1, 0xffffffff);
411
412	/*
413	 * Power off South Complex devices.
414	 *
415	 * There is a map (see a note below) of 64 devices with 2 bits per each
416	 * on 32-bit HW registers. The following calls set all devices to one
417	 * known initial state, i.e. PCI_D3hot. This is done in conjunction
418	 * with PMCSR setting in arch/x86/pci/intel_mid_pci.c.
419	 *
420	 * NOTE: The actual device mapping is provided by a platform at run
421	 * time using vendor capability of PCI configuration space.
422	 */
423	mid_pwr_set_state(pwr, 0, states[0]);
424	mid_pwr_set_state(pwr, 1, states[1]);
425	mid_pwr_set_state(pwr, 2, states[2]);
426	mid_pwr_set_state(pwr, 3, states[3]);
427
428	/* Send command to SCU */
429	ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG);
430	if (ret)
431		return ret;
432
433	for (i = 0; i < LSS_MAX_DEVS; i++) {
434		for (j = 0; j < LSS_MAX_SHARED_DEVS; j++)
435			pwr->lss[i][j].state = PCI_D3hot;
436	}
437
438	return 0;
439}
440
441static int pnw_set_initial_state(struct mid_pwr *pwr)
442{
443	/* On Penwell SRAM must stay powered on */
444	static const u32 states[] = {
445		0xf00fffff,		/* PM_SSC(0) */
446		0xffffffff,		/* PM_SSC(1) */
447		0xffffffff,		/* PM_SSC(2) */
448		0xffffffff,		/* PM_SSC(3) */
449	};
450	return mid_set_initial_state(pwr, states);
451}
452
453static int tng_set_initial_state(struct mid_pwr *pwr)
454{
455	static const u32 states[] = {
456		0xffffffff,		/* PM_SSC(0) */
457		0xffffffff,		/* PM_SSC(1) */
458		0xffffffff,		/* PM_SSC(2) */
459		0xffffffff,		/* PM_SSC(3) */
460	};
461	return mid_set_initial_state(pwr, states);
462}
463
464static const struct mid_pwr_device_info pnw_info = {
465	.set_initial_state = pnw_set_initial_state,
466};
467
468static const struct mid_pwr_device_info tng_info = {
469	.set_initial_state = tng_set_initial_state,
470};
471
472/* This table should be in sync with the one in drivers/pci/pci-mid.c */
473static const struct pci_device_id mid_pwr_pci_ids[] = {
474	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL), (kernel_ulong_t)&pnw_info },
475	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER), (kernel_ulong_t)&tng_info },
476	{}
477};
478
479static struct pci_driver mid_pwr_pci_driver = {
480	.name		= "intel_mid_pwr",
481	.probe		= mid_pwr_probe,
482	.id_table	= mid_pwr_pci_ids,
483};
484
485builtin_pci_driver(mid_pwr_pci_driver);
v4.17
 
  1/*
  2 * Intel MID Power Management Unit (PWRMU) device driver
  3 *
  4 * Copyright (C) 2016, Intel Corporation
  5 *
  6 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
  7 *
  8 * This program is free software; you can redistribute it and/or modify it
  9 * under the terms and conditions of the GNU General Public License,
 10 * version 2, as published by the Free Software Foundation.
 11 *
 12 * Intel MID Power Management Unit device driver handles the South Complex PCI
 13 * devices such as GPDMA, SPI, I2C, PWM, and so on. By default PCI core
 14 * modifies bits in PMCSR register in the PCI configuration space. This is not
 15 * enough on some SoCs like Intel Tangier. In such case PCI core sets a new
 16 * power state of the device in question through a PM hook registered in struct
 17 * pci_platform_pm_ops (see drivers/pci/pci-mid.c).
 18 */
 19
 20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 21
 22#include <linux/delay.h>
 23#include <linux/errno.h>
 24#include <linux/interrupt.h>
 25#include <linux/kernel.h>
 26#include <linux/export.h>
 27#include <linux/mutex.h>
 28#include <linux/pci.h>
 29
 30#include <asm/intel-mid.h>
 31
 32/* Registers */
 33#define PM_STS			0x00
 34#define PM_CMD			0x04
 35#define PM_ICS			0x08
 36#define PM_WKC(x)		(0x10 + (x) * 4)
 37#define PM_WKS(x)		(0x18 + (x) * 4)
 38#define PM_SSC(x)		(0x20 + (x) * 4)
 39#define PM_SSS(x)		(0x30 + (x) * 4)
 40
 41/* Bits in PM_STS */
 42#define PM_STS_BUSY		(1 << 8)
 43
 44/* Bits in PM_CMD */
 45#define PM_CMD_CMD(x)		((x) << 0)
 46#define PM_CMD_IOC		(1 << 8)
 47#define PM_CMD_CM_NOP		(0 << 9)
 48#define PM_CMD_CM_IMMEDIATE	(1 << 9)
 49#define PM_CMD_CM_DELAY		(2 << 9)
 50#define PM_CMD_CM_TRIGGER	(3 << 9)
 51
 52/* System states */
 53#define PM_CMD_SYS_STATE_S5	(5 << 16)
 54
 55/* Trigger variants */
 56#define PM_CMD_CFG_TRIGGER_NC	(3 << 19)
 57
 58/* Message to wait for TRIGGER_NC case */
 59#define TRIGGER_NC_MSG_2	(2 << 22)
 60
 61/* List of commands */
 62#define CMD_SET_CFG		0x01
 63
 64/* Bits in PM_ICS */
 65#define PM_ICS_INT_STATUS(x)	((x) & 0xff)
 66#define PM_ICS_IE		(1 << 8)
 67#define PM_ICS_IP		(1 << 9)
 68#define PM_ICS_SW_INT_STS	(1 << 10)
 69
 70/* List of interrupts */
 71#define INT_INVALID		0
 72#define INT_CMD_COMPLETE	1
 73#define INT_CMD_ERR		2
 74#define INT_WAKE_EVENT		3
 75#define INT_LSS_POWER_ERR	4
 76#define INT_S0iX_MSG_ERR	5
 77#define INT_NO_C6		6
 78#define INT_TRIGGER_ERR		7
 79#define INT_INACTIVITY		8
 80
 81/* South Complex devices */
 82#define LSS_MAX_SHARED_DEVS	4
 83#define LSS_MAX_DEVS		64
 84
 85#define LSS_WS_BITS		1	/* wake state width */
 86#define LSS_PWS_BITS		2	/* power state width */
 87
 88/* Supported device IDs */
 89#define PCI_DEVICE_ID_PENWELL	0x0828
 90#define PCI_DEVICE_ID_TANGIER	0x11a1
 91
 92struct mid_pwr_dev {
 93	struct pci_dev *pdev;
 94	pci_power_t state;
 95};
 96
 97struct mid_pwr {
 98	struct device *dev;
 99	void __iomem *regs;
100	int irq;
101	bool available;
102
103	struct mutex lock;
104	struct mid_pwr_dev lss[LSS_MAX_DEVS][LSS_MAX_SHARED_DEVS];
105};
106
107static struct mid_pwr *midpwr;
108
109static u32 mid_pwr_get_state(struct mid_pwr *pwr, int reg)
110{
111	return readl(pwr->regs + PM_SSS(reg));
112}
113
114static void mid_pwr_set_state(struct mid_pwr *pwr, int reg, u32 value)
115{
116	writel(value, pwr->regs + PM_SSC(reg));
117}
118
119static void mid_pwr_set_wake(struct mid_pwr *pwr, int reg, u32 value)
120{
121	writel(value, pwr->regs + PM_WKC(reg));
122}
123
124static void mid_pwr_interrupt_disable(struct mid_pwr *pwr)
125{
126	writel(~PM_ICS_IE, pwr->regs + PM_ICS);
127}
128
129static bool mid_pwr_is_busy(struct mid_pwr *pwr)
130{
131	return !!(readl(pwr->regs + PM_STS) & PM_STS_BUSY);
132}
133
134/* Wait 500ms that the latest PWRMU command finished */
135static int mid_pwr_wait(struct mid_pwr *pwr)
136{
137	unsigned int count = 500000;
138	bool busy;
139
140	do {
141		busy = mid_pwr_is_busy(pwr);
142		if (!busy)
143			return 0;
144		udelay(1);
145	} while (--count);
146
147	return -EBUSY;
148}
149
150static int mid_pwr_wait_for_cmd(struct mid_pwr *pwr, u8 cmd)
151{
152	writel(PM_CMD_CMD(cmd) | PM_CMD_CM_IMMEDIATE, pwr->regs + PM_CMD);
153	return mid_pwr_wait(pwr);
154}
155
156static int __update_power_state(struct mid_pwr *pwr, int reg, int bit, int new)
157{
158	int curstate;
159	u32 power;
160	int ret;
161
162	/* Check if the device is already in desired state */
163	power = mid_pwr_get_state(pwr, reg);
164	curstate = (power >> bit) & 3;
165	if (curstate == new)
166		return 0;
167
168	/* Update the power state */
169	mid_pwr_set_state(pwr, reg, (power & ~(3 << bit)) | (new << bit));
170
171	/* Send command to SCU */
172	ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG);
173	if (ret)
174		return ret;
175
176	/* Check if the device is already in desired state */
177	power = mid_pwr_get_state(pwr, reg);
178	curstate = (power >> bit) & 3;
179	if (curstate != new)
180		return -EAGAIN;
181
182	return 0;
183}
184
185static pci_power_t __find_weakest_power_state(struct mid_pwr_dev *lss,
186					      struct pci_dev *pdev,
187					      pci_power_t state)
188{
189	pci_power_t weakest = PCI_D3hot;
190	unsigned int j;
191
192	/* Find device in cache or first free cell */
193	for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) {
194		if (lss[j].pdev == pdev || !lss[j].pdev)
195			break;
196	}
197
198	/* Store the desired state in cache */
199	if (j < LSS_MAX_SHARED_DEVS) {
200		lss[j].pdev = pdev;
201		lss[j].state = state;
202	} else {
203		dev_WARN(&pdev->dev, "No room for device in PWRMU LSS cache\n");
204		weakest = state;
205	}
206
207	/* Find the power state we may use */
208	for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) {
209		if (lss[j].state < weakest)
210			weakest = lss[j].state;
211	}
212
213	return weakest;
214}
215
216static int __set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev,
217			     pci_power_t state, int id, int reg, int bit)
218{
219	const char *name;
220	int ret;
221
222	state = __find_weakest_power_state(pwr->lss[id], pdev, state);
223	name = pci_power_name(state);
224
225	ret = __update_power_state(pwr, reg, bit, (__force int)state);
226	if (ret) {
227		dev_warn(&pdev->dev, "Can't set power state %s: %d\n", name, ret);
228		return ret;
229	}
230
231	dev_vdbg(&pdev->dev, "Set power state %s\n", name);
232	return 0;
233}
234
235static int mid_pwr_set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev,
236				   pci_power_t state)
237{
238	int id, reg, bit;
239	int ret;
240
241	id = intel_mid_pwr_get_lss_id(pdev);
242	if (id < 0)
243		return id;
244
245	reg = (id * LSS_PWS_BITS) / 32;
246	bit = (id * LSS_PWS_BITS) % 32;
247
248	/* We support states between PCI_D0 and PCI_D3hot */
249	if (state < PCI_D0)
250		state = PCI_D0;
251	if (state > PCI_D3hot)
252		state = PCI_D3hot;
253
254	mutex_lock(&pwr->lock);
255	ret = __set_power_state(pwr, pdev, state, id, reg, bit);
256	mutex_unlock(&pwr->lock);
257	return ret;
258}
259
260int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state)
261{
262	struct mid_pwr *pwr = midpwr;
263	int ret = 0;
264
265	might_sleep();
266
267	if (pwr && pwr->available)
268		ret = mid_pwr_set_power_state(pwr, pdev, state);
269	dev_vdbg(&pdev->dev, "set_power_state() returns %d\n", ret);
270
271	return 0;
272}
273
274pci_power_t intel_mid_pci_get_power_state(struct pci_dev *pdev)
275{
276	struct mid_pwr *pwr = midpwr;
277	int id, reg, bit;
278	u32 power;
279
280	if (!pwr || !pwr->available)
281		return PCI_UNKNOWN;
282
283	id = intel_mid_pwr_get_lss_id(pdev);
284	if (id < 0)
285		return PCI_UNKNOWN;
286
287	reg = (id * LSS_PWS_BITS) / 32;
288	bit = (id * LSS_PWS_BITS) % 32;
289	power = mid_pwr_get_state(pwr, reg);
290	return (__force pci_power_t)((power >> bit) & 3);
291}
292
293void intel_mid_pwr_power_off(void)
294{
295	struct mid_pwr *pwr = midpwr;
296	u32 cmd = PM_CMD_SYS_STATE_S5 |
297		  PM_CMD_CMD(CMD_SET_CFG) |
298		  PM_CMD_CM_TRIGGER |
299		  PM_CMD_CFG_TRIGGER_NC |
300		  TRIGGER_NC_MSG_2;
301
302	/* Send command to SCU */
303	writel(cmd, pwr->regs + PM_CMD);
304	mid_pwr_wait(pwr);
305}
306
307int intel_mid_pwr_get_lss_id(struct pci_dev *pdev)
308{
309	int vndr;
310	u8 id;
311
312	/*
313	 * Mapping to PWRMU index is kept in the Logical SubSystem ID byte of
314	 * Vendor capability.
315	 */
316	vndr = pci_find_capability(pdev, PCI_CAP_ID_VNDR);
317	if (!vndr)
318		return -EINVAL;
319
320	/* Read the Logical SubSystem ID byte */
321	pci_read_config_byte(pdev, vndr + INTEL_MID_PWR_LSS_OFFSET, &id);
322	if (!(id & INTEL_MID_PWR_LSS_TYPE))
323		return -ENODEV;
324
325	id &= ~INTEL_MID_PWR_LSS_TYPE;
326	if (id >= LSS_MAX_DEVS)
327		return -ERANGE;
328
329	return id;
330}
331
332static irqreturn_t mid_pwr_irq_handler(int irq, void *dev_id)
333{
334	struct mid_pwr *pwr = dev_id;
335	u32 ics;
336
337	ics = readl(pwr->regs + PM_ICS);
338	if (!(ics & PM_ICS_IP))
339		return IRQ_NONE;
340
341	writel(ics | PM_ICS_IP, pwr->regs + PM_ICS);
342
343	dev_warn(pwr->dev, "Unexpected IRQ: %#x\n", PM_ICS_INT_STATUS(ics));
344	return IRQ_HANDLED;
345}
346
347struct mid_pwr_device_info {
348	int (*set_initial_state)(struct mid_pwr *pwr);
349};
350
351static int mid_pwr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
352{
353	struct mid_pwr_device_info *info = (void *)id->driver_data;
354	struct device *dev = &pdev->dev;
355	struct mid_pwr *pwr;
356	int ret;
357
358	ret = pcim_enable_device(pdev);
359	if (ret < 0) {
360		dev_err(&pdev->dev, "error: could not enable device\n");
361		return ret;
362	}
363
364	ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
365	if (ret) {
366		dev_err(&pdev->dev, "I/O memory remapping failed\n");
367		return ret;
368	}
369
370	pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL);
371	if (!pwr)
372		return -ENOMEM;
373
374	pwr->dev = dev;
375	pwr->regs = pcim_iomap_table(pdev)[0];
376	pwr->irq = pdev->irq;
377
378	mutex_init(&pwr->lock);
379
380	/* Disable interrupts */
381	mid_pwr_interrupt_disable(pwr);
382
383	if (info && info->set_initial_state) {
384		ret = info->set_initial_state(pwr);
385		if (ret)
386			dev_warn(dev, "Can't set initial state: %d\n", ret);
387	}
388
389	ret = devm_request_irq(dev, pdev->irq, mid_pwr_irq_handler,
390			       IRQF_NO_SUSPEND, pci_name(pdev), pwr);
391	if (ret)
392		return ret;
393
394	pwr->available = true;
395	midpwr = pwr;
396
397	pci_set_drvdata(pdev, pwr);
398	return 0;
399}
400
401static int mid_set_initial_state(struct mid_pwr *pwr, const u32 *states)
402{
403	unsigned int i, j;
404	int ret;
405
406	/*
407	 * Enable wake events.
408	 *
409	 * PWRMU supports up to 32 sources for wake up the system. Ungate them
410	 * all here.
411	 */
412	mid_pwr_set_wake(pwr, 0, 0xffffffff);
413	mid_pwr_set_wake(pwr, 1, 0xffffffff);
414
415	/*
416	 * Power off South Complex devices.
417	 *
418	 * There is a map (see a note below) of 64 devices with 2 bits per each
419	 * on 32-bit HW registers. The following calls set all devices to one
420	 * known initial state, i.e. PCI_D3hot. This is done in conjunction
421	 * with PMCSR setting in arch/x86/pci/intel_mid_pci.c.
422	 *
423	 * NOTE: The actual device mapping is provided by a platform at run
424	 * time using vendor capability of PCI configuration space.
425	 */
426	mid_pwr_set_state(pwr, 0, states[0]);
427	mid_pwr_set_state(pwr, 1, states[1]);
428	mid_pwr_set_state(pwr, 2, states[2]);
429	mid_pwr_set_state(pwr, 3, states[3]);
430
431	/* Send command to SCU */
432	ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG);
433	if (ret)
434		return ret;
435
436	for (i = 0; i < LSS_MAX_DEVS; i++) {
437		for (j = 0; j < LSS_MAX_SHARED_DEVS; j++)
438			pwr->lss[i][j].state = PCI_D3hot;
439	}
440
441	return 0;
442}
443
444static int pnw_set_initial_state(struct mid_pwr *pwr)
445{
446	/* On Penwell SRAM must stay powered on */
447	static const u32 states[] = {
448		0xf00fffff,		/* PM_SSC(0) */
449		0xffffffff,		/* PM_SSC(1) */
450		0xffffffff,		/* PM_SSC(2) */
451		0xffffffff,		/* PM_SSC(3) */
452	};
453	return mid_set_initial_state(pwr, states);
454}
455
456static int tng_set_initial_state(struct mid_pwr *pwr)
457{
458	static const u32 states[] = {
459		0xffffffff,		/* PM_SSC(0) */
460		0xffffffff,		/* PM_SSC(1) */
461		0xffffffff,		/* PM_SSC(2) */
462		0xffffffff,		/* PM_SSC(3) */
463	};
464	return mid_set_initial_state(pwr, states);
465}
466
467static const struct mid_pwr_device_info pnw_info = {
468	.set_initial_state = pnw_set_initial_state,
469};
470
471static const struct mid_pwr_device_info tng_info = {
472	.set_initial_state = tng_set_initial_state,
473};
474
475/* This table should be in sync with the one in drivers/pci/pci-mid.c */
476static const struct pci_device_id mid_pwr_pci_ids[] = {
477	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL), (kernel_ulong_t)&pnw_info },
478	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER), (kernel_ulong_t)&tng_info },
479	{}
480};
481
482static struct pci_driver mid_pwr_pci_driver = {
483	.name		= "intel_mid_pwr",
484	.probe		= mid_pwr_probe,
485	.id_table	= mid_pwr_pci_ids,
486};
487
488builtin_pci_driver(mid_pwr_pci_driver);