x86/platform/intel-mid: Enable SD card detection on Merrifield
[deliverable/linux.git] / arch / x86 / platform / intel-mid / pwr.c
CommitLineData
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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>
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24#include <linux/interrupt.h>
25#include <linux/kernel.h>
cc3ae7b0 26#include <linux/export.h>
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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)
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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)
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51#define PM_CMD_D3cold (1 << 21)
52
53/* List of commands */
54#define CMD_SET_CFG 0x01
55
56/* Bits in PM_ICS */
57#define PM_ICS_INT_STATUS(x) ((x) & 0xff)
58#define PM_ICS_IE (1 << 8)
59#define PM_ICS_IP (1 << 9)
60#define PM_ICS_SW_INT_STS (1 << 10)
61
62/* List of interrupts */
63#define INT_INVALID 0
64#define INT_CMD_COMPLETE 1
65#define INT_CMD_ERR 2
66#define INT_WAKE_EVENT 3
67#define INT_LSS_POWER_ERR 4
68#define INT_S0iX_MSG_ERR 5
69#define INT_NO_C6 6
70#define INT_TRIGGER_ERR 7
71#define INT_INACTIVITY 8
72
73/* South Complex devices */
74#define LSS_MAX_SHARED_DEVS 4
75#define LSS_MAX_DEVS 64
76
77#define LSS_WS_BITS 1 /* wake state width */
78#define LSS_PWS_BITS 2 /* power state width */
79
80/* Supported device IDs */
ca22312d 81#define PCI_DEVICE_ID_PENWELL 0x0828
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82#define PCI_DEVICE_ID_TANGIER 0x11a1
83
84struct mid_pwr_dev {
85 struct pci_dev *pdev;
86 pci_power_t state;
87};
88
89struct mid_pwr {
90 struct device *dev;
91 void __iomem *regs;
92 int irq;
93 bool available;
94
95 struct mutex lock;
96 struct mid_pwr_dev lss[LSS_MAX_DEVS][LSS_MAX_SHARED_DEVS];
97};
98
99static struct mid_pwr *midpwr;
100
101static u32 mid_pwr_get_state(struct mid_pwr *pwr, int reg)
102{
103 return readl(pwr->regs + PM_SSS(reg));
104}
105
106static void mid_pwr_set_state(struct mid_pwr *pwr, int reg, u32 value)
107{
108 writel(value, pwr->regs + PM_SSC(reg));
109}
110
111static void mid_pwr_set_wake(struct mid_pwr *pwr, int reg, u32 value)
112{
113 writel(value, pwr->regs + PM_WKC(reg));
114}
115
116static void mid_pwr_interrupt_disable(struct mid_pwr *pwr)
117{
118 writel(~PM_ICS_IE, pwr->regs + PM_ICS);
119}
120
121static bool mid_pwr_is_busy(struct mid_pwr *pwr)
122{
123 return !!(readl(pwr->regs + PM_STS) & PM_STS_BUSY);
124}
125
126/* Wait 500ms that the latest PWRMU command finished */
127static int mid_pwr_wait(struct mid_pwr *pwr)
128{
129 unsigned int count = 500000;
130 bool busy;
131
132 do {
133 busy = mid_pwr_is_busy(pwr);
134 if (!busy)
135 return 0;
136 udelay(1);
137 } while (--count);
138
139 return -EBUSY;
140}
141
142static int mid_pwr_wait_for_cmd(struct mid_pwr *pwr, u8 cmd)
143{
70b5b18f 144 writel(PM_CMD_CMD(cmd) | PM_CMD_CM_IMMEDIATE, pwr->regs + PM_CMD);
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145 return mid_pwr_wait(pwr);
146}
147
148static int __update_power_state(struct mid_pwr *pwr, int reg, int bit, int new)
149{
150 int curstate;
151 u32 power;
152 int ret;
153
154 /* Check if the device is already in desired state */
155 power = mid_pwr_get_state(pwr, reg);
156 curstate = (power >> bit) & 3;
157 if (curstate == new)
158 return 0;
159
160 /* Update the power state */
161 mid_pwr_set_state(pwr, reg, (power & ~(3 << bit)) | (new << bit));
162
163 /* Send command to SCU */
164 ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG);
165 if (ret)
166 return ret;
167
168 /* Check if the device is already in desired state */
169 power = mid_pwr_get_state(pwr, reg);
170 curstate = (power >> bit) & 3;
171 if (curstate != new)
172 return -EAGAIN;
173
174 return 0;
175}
176
177static pci_power_t __find_weakest_power_state(struct mid_pwr_dev *lss,
178 struct pci_dev *pdev,
179 pci_power_t state)
180{
181 pci_power_t weakest = PCI_D3hot;
182 unsigned int j;
183
184 /* Find device in cache or first free cell */
185 for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) {
186 if (lss[j].pdev == pdev || !lss[j].pdev)
187 break;
188 }
189
190 /* Store the desired state in cache */
191 if (j < LSS_MAX_SHARED_DEVS) {
192 lss[j].pdev = pdev;
193 lss[j].state = state;
194 } else {
195 dev_WARN(&pdev->dev, "No room for device in PWRMU LSS cache\n");
196 weakest = state;
197 }
198
199 /* Find the power state we may use */
200 for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) {
201 if (lss[j].state < weakest)
202 weakest = lss[j].state;
203 }
204
205 return weakest;
206}
207
208static int __set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev,
209 pci_power_t state, int id, int reg, int bit)
210{
211 const char *name;
212 int ret;
213
214 state = __find_weakest_power_state(pwr->lss[id], pdev, state);
215 name = pci_power_name(state);
216
217 ret = __update_power_state(pwr, reg, bit, (__force int)state);
218 if (ret) {
219 dev_warn(&pdev->dev, "Can't set power state %s: %d\n", name, ret);
220 return ret;
221 }
222
223 dev_vdbg(&pdev->dev, "Set power state %s\n", name);
224 return 0;
225}
226
227static int mid_pwr_set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev,
228 pci_power_t state)
229{
230 int id, reg, bit;
231 int ret;
232
233 id = intel_mid_pwr_get_lss_id(pdev);
234 if (id < 0)
235 return id;
236
237 reg = (id * LSS_PWS_BITS) / 32;
238 bit = (id * LSS_PWS_BITS) % 32;
239
240 /* We support states between PCI_D0 and PCI_D3hot */
241 if (state < PCI_D0)
242 state = PCI_D0;
243 if (state > PCI_D3hot)
244 state = PCI_D3hot;
245
246 mutex_lock(&pwr->lock);
247 ret = __set_power_state(pwr, pdev, state, id, reg, bit);
248 mutex_unlock(&pwr->lock);
249 return ret;
250}
251
252int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state)
253{
254 struct mid_pwr *pwr = midpwr;
255 int ret = 0;
256
257 might_sleep();
258
259 if (pwr && pwr->available)
260 ret = mid_pwr_set_power_state(pwr, pdev, state);
261 dev_vdbg(&pdev->dev, "set_power_state() returns %d\n", ret);
262
263 return 0;
264}
265EXPORT_SYMBOL_GPL(intel_mid_pci_set_power_state);
266
267int intel_mid_pwr_get_lss_id(struct pci_dev *pdev)
268{
269 int vndr;
270 u8 id;
271
272 /*
273 * Mapping to PWRMU index is kept in the Logical SubSystem ID byte of
274 * Vendor capability.
275 */
276 vndr = pci_find_capability(pdev, PCI_CAP_ID_VNDR);
277 if (!vndr)
278 return -EINVAL;
279
280 /* Read the Logical SubSystem ID byte */
281 pci_read_config_byte(pdev, vndr + INTEL_MID_PWR_LSS_OFFSET, &id);
282 if (!(id & INTEL_MID_PWR_LSS_TYPE))
283 return -ENODEV;
284
285 id &= ~INTEL_MID_PWR_LSS_TYPE;
286 if (id >= LSS_MAX_DEVS)
287 return -ERANGE;
288
289 return id;
290}
291
292static irqreturn_t mid_pwr_irq_handler(int irq, void *dev_id)
293{
294 struct mid_pwr *pwr = dev_id;
295 u32 ics;
296
297 ics = readl(pwr->regs + PM_ICS);
298 if (!(ics & PM_ICS_IP))
299 return IRQ_NONE;
300
301 writel(ics | PM_ICS_IP, pwr->regs + PM_ICS);
302
303 dev_warn(pwr->dev, "Unexpected IRQ: %#x\n", PM_ICS_INT_STATUS(ics));
304 return IRQ_HANDLED;
305}
306
307struct mid_pwr_device_info {
308 int (*set_initial_state)(struct mid_pwr *pwr);
309};
310
311static int mid_pwr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
312{
313 struct mid_pwr_device_info *info = (void *)id->driver_data;
314 struct device *dev = &pdev->dev;
315 struct mid_pwr *pwr;
316 int ret;
317
318 ret = pcim_enable_device(pdev);
319 if (ret < 0) {
320 dev_err(&pdev->dev, "error: could not enable device\n");
321 return ret;
322 }
323
324 ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
325 if (ret) {
326 dev_err(&pdev->dev, "I/O memory remapping failed\n");
327 return ret;
328 }
329
330 pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL);
331 if (!pwr)
332 return -ENOMEM;
333
334 pwr->dev = dev;
335 pwr->regs = pcim_iomap_table(pdev)[0];
336 pwr->irq = pdev->irq;
337
338 mutex_init(&pwr->lock);
339
340 /* Disable interrupts */
341 mid_pwr_interrupt_disable(pwr);
342
343 if (info && info->set_initial_state) {
344 ret = info->set_initial_state(pwr);
345 if (ret)
346 dev_warn(dev, "Can't set initial state: %d\n", ret);
347 }
348
349 ret = devm_request_irq(dev, pdev->irq, mid_pwr_irq_handler,
350 IRQF_NO_SUSPEND, pci_name(pdev), pwr);
351 if (ret)
352 return ret;
353
354 pwr->available = true;
355 midpwr = pwr;
356
357 pci_set_drvdata(pdev, pwr);
358 return 0;
359}
360
ca22312d 361static int mid_set_initial_state(struct mid_pwr *pwr)
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362{
363 unsigned int i, j;
364 int ret;
365
366 /*
367 * Enable wake events.
368 *
369 * PWRMU supports up to 32 sources for wake up the system. Ungate them
370 * all here.
371 */
372 mid_pwr_set_wake(pwr, 0, 0xffffffff);
373 mid_pwr_set_wake(pwr, 1, 0xffffffff);
374
375 /*
376 * Power off South Complex devices.
377 *
378 * There is a map (see a note below) of 64 devices with 2 bits per each
379 * on 32-bit HW registers. The following calls set all devices to one
380 * known initial state, i.e. PCI_D3hot. This is done in conjunction
381 * with PMCSR setting in arch/x86/pci/intel_mid_pci.c.
382 *
383 * NOTE: The actual device mapping is provided by a platform at run
384 * time using vendor capability of PCI configuration space.
385 */
386 mid_pwr_set_state(pwr, 0, 0xffffffff);
387 mid_pwr_set_state(pwr, 1, 0xffffffff);
388 mid_pwr_set_state(pwr, 2, 0xffffffff);
389 mid_pwr_set_state(pwr, 3, 0xffffffff);
390
391 /* Send command to SCU */
392 ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG);
393 if (ret)
394 return ret;
395
396 for (i = 0; i < LSS_MAX_DEVS; i++) {
397 for (j = 0; j < LSS_MAX_SHARED_DEVS; j++)
398 pwr->lss[i][j].state = PCI_D3hot;
399 }
400
401 return 0;
402}
403
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404static const struct mid_pwr_device_info mid_info = {
405 .set_initial_state = mid_set_initial_state,
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406};
407
408static const struct pci_device_id mid_pwr_pci_ids[] = {
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409 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL), (kernel_ulong_t)&mid_info },
410 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER), (kernel_ulong_t)&mid_info },
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411 {}
412};
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413
414static struct pci_driver mid_pwr_pci_driver = {
415 .name = "intel_mid_pwr",
416 .probe = mid_pwr_probe,
417 .id_table = mid_pwr_pci_ids,
418};
419
420builtin_pci_driver(mid_pwr_pci_driver);
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