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5823d089 AS |
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> | |
5823d089 AS |
24 | #include <linux/interrupt.h> |
25 | #include <linux/kernel.h> | |
cc3ae7b0 | 26 | #include <linux/export.h> |
5823d089 AS |
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) | |
70b5b18f AS |
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) | |
5823d089 AS |
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 |
5823d089 AS |
82 | #define PCI_DEVICE_ID_TANGIER 0x11a1 |
83 | ||
84 | struct mid_pwr_dev { | |
85 | struct pci_dev *pdev; | |
86 | pci_power_t state; | |
87 | }; | |
88 | ||
89 | struct 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 | ||
99 | static struct mid_pwr *midpwr; | |
100 | ||
101 | static u32 mid_pwr_get_state(struct mid_pwr *pwr, int reg) | |
102 | { | |
103 | return readl(pwr->regs + PM_SSS(reg)); | |
104 | } | |
105 | ||
106 | static void mid_pwr_set_state(struct mid_pwr *pwr, int reg, u32 value) | |
107 | { | |
108 | writel(value, pwr->regs + PM_SSC(reg)); | |
109 | } | |
110 | ||
111 | static void mid_pwr_set_wake(struct mid_pwr *pwr, int reg, u32 value) | |
112 | { | |
113 | writel(value, pwr->regs + PM_WKC(reg)); | |
114 | } | |
115 | ||
116 | static void mid_pwr_interrupt_disable(struct mid_pwr *pwr) | |
117 | { | |
118 | writel(~PM_ICS_IE, pwr->regs + PM_ICS); | |
119 | } | |
120 | ||
121 | static 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 */ | |
127 | static 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 | ||
142 | static 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); |
5823d089 AS |
145 | return mid_pwr_wait(pwr); |
146 | } | |
147 | ||
148 | static 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 | ||
177 | static 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 | ||
208 | static 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 | ||
227 | static 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 | ||
252 | int 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 | } | |
265 | EXPORT_SYMBOL_GPL(intel_mid_pci_set_power_state); | |
266 | ||
267 | int 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 | ||
292 | static 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 | ||
307 | struct mid_pwr_device_info { | |
308 | int (*set_initial_state)(struct mid_pwr *pwr); | |
309 | }; | |
310 | ||
311 | static 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 | 361 | static int mid_set_initial_state(struct mid_pwr *pwr) |
5823d089 AS |
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 | ||
ca22312d AS |
404 | static const struct mid_pwr_device_info mid_info = { |
405 | .set_initial_state = mid_set_initial_state, | |
5823d089 AS |
406 | }; |
407 | ||
408 | static const struct pci_device_id mid_pwr_pci_ids[] = { | |
ca22312d AS |
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 }, | |
5823d089 AS |
411 | {} |
412 | }; | |
5823d089 AS |
413 | |
414 | static 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 | ||
420 | builtin_pci_driver(mid_pwr_pci_driver); |