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1/*
2 * Intel Sunrisepoint LPSS core support.
3 *
4 * Copyright (C) 2015, Intel Corporation
5 *
6 * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
7 * Mika Westerberg <mika.westerberg@linux.intel.com>
8 * Heikki Krogerus <heikki.krogerus@linux.intel.com>
9 * Jarkko Nikula <jarkko.nikula@linux.intel.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16#include <linux/clk.h>
17#include <linux/clkdev.h>
18#include <linux/clk-provider.h>
19#include <linux/debugfs.h>
20#include <linux/idr.h>
21#include <linux/ioport.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/mfd/core.h>
25#include <linux/pm_qos.h>
26#include <linux/pm_runtime.h>
27#include <linux/property.h>
28#include <linux/seq_file.h>
29#include <linux/io-64-nonatomic-lo-hi.h>
30
31#include "intel-lpss.h"
32
33#define LPSS_DEV_OFFSET 0x000
34#define LPSS_DEV_SIZE 0x200
35#define LPSS_PRIV_OFFSET 0x200
36#define LPSS_PRIV_SIZE 0x100
37#define LPSS_IDMA64_OFFSET 0x800
38#define LPSS_IDMA64_SIZE 0x800
39
40/* Offsets from lpss->priv */
41#define LPSS_PRIV_RESETS 0x04
42#define LPSS_PRIV_RESETS_FUNC BIT(2)
43#define LPSS_PRIV_RESETS_IDMA 0x3
44
45#define LPSS_PRIV_ACTIVELTR 0x10
46#define LPSS_PRIV_IDLELTR 0x14
47
48#define LPSS_PRIV_LTR_REQ BIT(15)
49#define LPSS_PRIV_LTR_SCALE_MASK 0xc00
50#define LPSS_PRIV_LTR_SCALE_1US 0x800
51#define LPSS_PRIV_LTR_SCALE_32US 0xc00
52#define LPSS_PRIV_LTR_VALUE_MASK 0x3ff
53
54#define LPSS_PRIV_SSP_REG 0x20
55#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN BIT(0)
56
57#define LPSS_PRIV_REMAP_ADDR 0x40
58
59#define LPSS_PRIV_CAPS 0xfc
60#define LPSS_PRIV_CAPS_NO_IDMA BIT(8)
61#define LPSS_PRIV_CAPS_TYPE_SHIFT 4
62#define LPSS_PRIV_CAPS_TYPE_MASK (0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
63
64/* This matches the type field in CAPS register */
65enum intel_lpss_dev_type {
66 LPSS_DEV_I2C = 0,
67 LPSS_DEV_UART,
68 LPSS_DEV_SPI,
69};
70
71struct intel_lpss {
72 const struct intel_lpss_platform_info *info;
73 enum intel_lpss_dev_type type;
74 struct clk *clk;
75 struct clk_lookup *clock;
76 struct mfd_cell *cell;
77 struct device *dev;
78 void __iomem *priv;
79 int devid;
80 u32 caps;
81 u32 active_ltr;
82 u32 idle_ltr;
83 struct dentry *debugfs;
84};
85
86static const struct resource intel_lpss_dev_resources[] = {
87 DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
88 DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
89 DEFINE_RES_IRQ(0),
90};
91
92static const struct resource intel_lpss_idma64_resources[] = {
93 DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
94 DEFINE_RES_IRQ(0),
95};
96
97#define LPSS_IDMA64_DRIVER_NAME "idma64"
98
99/*
100 * Cells needs to be ordered so that the iDMA is created first. This is
101 * because we need to be sure the DMA is available when the host controller
102 * driver is probed.
103 */
104static const struct mfd_cell intel_lpss_idma64_cell = {
105 .name = LPSS_IDMA64_DRIVER_NAME,
106 .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
107 .resources = intel_lpss_idma64_resources,
108};
109
110static const struct mfd_cell intel_lpss_i2c_cell = {
111 .name = "i2c_designware",
112 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
113 .resources = intel_lpss_dev_resources,
114};
115
116static const struct mfd_cell intel_lpss_uart_cell = {
117 .name = "dw-apb-uart",
118 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
119 .resources = intel_lpss_dev_resources,
120};
121
122static const struct mfd_cell intel_lpss_spi_cell = {
123 .name = "pxa2xx-spi",
124 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
125 .resources = intel_lpss_dev_resources,
126};
127
128static DEFINE_IDA(intel_lpss_devid_ida);
129static struct dentry *intel_lpss_debugfs;
130
131static int intel_lpss_request_dma_module(const char *name)
132{
133 static bool intel_lpss_dma_requested;
134
135 if (intel_lpss_dma_requested)
136 return 0;
137
138 intel_lpss_dma_requested = true;
139 return request_module("%s", name);
140}
141
142static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
143{
144 lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
145 lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
146}
147
148static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
149{
150 struct dentry *dir;
151
152 dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
153 if (IS_ERR(dir))
154 return PTR_ERR(dir);
155
156 /* Cache the values into lpss structure */
157 intel_lpss_cache_ltr(lpss);
158
159 debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
160 debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
161 debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
162
163 lpss->debugfs = dir;
164 return 0;
165}
166
167static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
168{
169 debugfs_remove_recursive(lpss->debugfs);
170}
171
172static void intel_lpss_ltr_set(struct device *dev, s32 val)
173{
174 struct intel_lpss *lpss = dev_get_drvdata(dev);
175 u32 ltr;
176
177 /*
178 * Program latency tolerance (LTR) accordingly what has been asked
179 * by the PM QoS layer or disable it in case we were passed
180 * negative value or PM_QOS_LATENCY_ANY.
181 */
182 ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
183
184 if (val == PM_QOS_LATENCY_ANY || val < 0) {
185 ltr &= ~LPSS_PRIV_LTR_REQ;
186 } else {
187 ltr |= LPSS_PRIV_LTR_REQ;
188 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
189 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
190
191 if (val > LPSS_PRIV_LTR_VALUE_MASK)
192 ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
193 else
194 ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
195 }
196
197 if (ltr == lpss->active_ltr)
198 return;
199
200 writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
201 writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
202
203 /* Cache the values into lpss structure */
204 intel_lpss_cache_ltr(lpss);
205}
206
207static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
208{
209 lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
210 dev_pm_qos_expose_latency_tolerance(lpss->dev);
211}
212
213static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
214{
215 dev_pm_qos_hide_latency_tolerance(lpss->dev);
216 lpss->dev->power.set_latency_tolerance = NULL;
217}
218
219static int intel_lpss_assign_devs(struct intel_lpss *lpss)
220{
221 const struct mfd_cell *cell;
222 unsigned int type;
223
224 type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
225 type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
226
227 switch (type) {
228 case LPSS_DEV_I2C:
229 cell = &intel_lpss_i2c_cell;
230 break;
231 case LPSS_DEV_UART:
232 cell = &intel_lpss_uart_cell;
233 break;
234 case LPSS_DEV_SPI:
235 cell = &intel_lpss_spi_cell;
236 break;
237 default:
238 return -ENODEV;
239 }
240
241 lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL);
242 if (!lpss->cell)
243 return -ENOMEM;
244
245 lpss->type = type;
246
247 return 0;
248}
249
250static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
251{
252 return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
253}
254
255static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
256{
257 resource_size_t addr = lpss->info->mem->start;
258
259 lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR);
260}
261
262static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
263{
264 u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
265
266 /* Bring out the device from reset */
267 writel(value, lpss->priv + LPSS_PRIV_RESETS);
268}
269
270static void intel_lpss_init_dev(const struct intel_lpss *lpss)
271{
272 u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
273
274 intel_lpss_deassert_reset(lpss);
275
276 if (!intel_lpss_has_idma(lpss))
277 return;
278
279 intel_lpss_set_remap_addr(lpss);
280
281 /* Make sure that SPI multiblock DMA transfers are re-enabled */
282 if (lpss->type == LPSS_DEV_SPI)
283 writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
284}
285
286static void intel_lpss_unregister_clock_tree(struct clk *clk)
287{
288 struct clk *parent;
289
290 while (clk) {
291 parent = clk_get_parent(clk);
292 clk_unregister(clk);
293 clk = parent;
294 }
295}
296
297static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
298 const char *devname,
299 struct clk **clk)
300{
301 char name[32];
302 struct clk *tmp = *clk;
303
304 snprintf(name, sizeof(name), "%s-enable", devname);
305 tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
306 lpss->priv, 0, 0, NULL);
307 if (IS_ERR(tmp))
308 return PTR_ERR(tmp);
309
310 snprintf(name, sizeof(name), "%s-div", devname);
311 tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
312 0, lpss->priv, 1, 15, 16, 15, 0,
313 NULL);
314 if (IS_ERR(tmp))
315 return PTR_ERR(tmp);
316 *clk = tmp;
317
318 snprintf(name, sizeof(name), "%s-update", devname);
319 tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
320 CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
321 if (IS_ERR(tmp))
322 return PTR_ERR(tmp);
323 *clk = tmp;
324
325 return 0;
326}
327
328static int intel_lpss_register_clock(struct intel_lpss *lpss)
329{
330 const struct mfd_cell *cell = lpss->cell;
331 struct clk *clk;
332 char devname[24];
333 int ret;
334
335 if (!lpss->info->clk_rate)
336 return 0;
337
338 /* Root clock */
339 clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
340 CLK_IS_ROOT, lpss->info->clk_rate);
341 if (IS_ERR(clk))
342 return PTR_ERR(clk);
343
344 snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
345
346 /*
347 * Support for clock divider only if it has some preset value.
348 * Otherwise we assume that the divider is not used.
349 */
350 if (lpss->type != LPSS_DEV_I2C) {
351 ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
352 if (ret)
353 goto err_clk_register;
354 }
355
356 ret = -ENOMEM;
357
358 /* Clock for the host controller */
359 lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
360 if (!lpss->clock)
361 goto err_clk_register;
362
363 lpss->clk = clk;
364
365 return 0;
366
367err_clk_register:
368 intel_lpss_unregister_clock_tree(clk);
369
370 return ret;
371}
372
373static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
374{
375 if (IS_ERR_OR_NULL(lpss->clk))
376 return;
377
378 clkdev_drop(lpss->clock);
379 intel_lpss_unregister_clock_tree(lpss->clk);
380}
381
382int intel_lpss_probe(struct device *dev,
383 const struct intel_lpss_platform_info *info)
384{
385 struct intel_lpss *lpss;
386 int ret;
387
388 if (!info || !info->mem || info->irq <= 0)
389 return -EINVAL;
390
391 lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
392 if (!lpss)
393 return -ENOMEM;
394
395 lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
396 LPSS_PRIV_SIZE);
397 if (!lpss->priv)
398 return -ENOMEM;
399
400 lpss->info = info;
401 lpss->dev = dev;
402 lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
403
404 dev_set_drvdata(dev, lpss);
405
406 ret = intel_lpss_assign_devs(lpss);
407 if (ret)
408 return ret;
409
410 lpss->cell->pset = info->pset;
411
412 intel_lpss_init_dev(lpss);
413
414 lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
415 if (lpss->devid < 0)
416 return lpss->devid;
417
418 ret = intel_lpss_register_clock(lpss);
419 if (ret)
420 goto err_clk_register;
421
422 intel_lpss_ltr_expose(lpss);
423
424 ret = intel_lpss_debugfs_add(lpss);
425 if (ret)
426 dev_warn(dev, "Failed to create debugfs entries\n");
427
428 if (intel_lpss_has_idma(lpss)) {
429 /*
430 * Ensure the DMA driver is loaded before the host
431 * controller device appears, so that the host controller
432 * driver can request its DMA channels as early as
433 * possible.
434 *
435 * If the DMA module is not there that's OK as well.
436 */
437 intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
438
439 ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
440 1, info->mem, info->irq, NULL);
441 if (ret)
442 dev_warn(dev, "Failed to add %s, fallback to PIO\n",
443 LPSS_IDMA64_DRIVER_NAME);
444 }
445
446 ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
447 1, info->mem, info->irq, NULL);
448 if (ret)
449 goto err_remove_ltr;
450
451 return 0;
452
453err_remove_ltr:
454 intel_lpss_debugfs_remove(lpss);
455 intel_lpss_ltr_hide(lpss);
456 intel_lpss_unregister_clock(lpss);
457
458err_clk_register:
459 ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
460
461 return ret;
462}
463EXPORT_SYMBOL_GPL(intel_lpss_probe);
464
465void intel_lpss_remove(struct device *dev)
466{
467 struct intel_lpss *lpss = dev_get_drvdata(dev);
468
469 mfd_remove_devices(dev);
470 intel_lpss_debugfs_remove(lpss);
471 intel_lpss_ltr_hide(lpss);
472 intel_lpss_unregister_clock(lpss);
473 ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
474}
475EXPORT_SYMBOL_GPL(intel_lpss_remove);
476
477static int resume_lpss_device(struct device *dev, void *data)
478{
479 pm_runtime_resume(dev);
480 return 0;
481}
482
483int intel_lpss_prepare(struct device *dev)
484{
485 /*
486 * Resume both child devices before entering system sleep. This
487 * ensures that they are in proper state before they get suspended.
488 */
489 device_for_each_child_reverse(dev, NULL, resume_lpss_device);
490 return 0;
491}
492EXPORT_SYMBOL_GPL(intel_lpss_prepare);
493
494int intel_lpss_suspend(struct device *dev)
495{
496 return 0;
497}
498EXPORT_SYMBOL_GPL(intel_lpss_suspend);
499
500int intel_lpss_resume(struct device *dev)
501{
502 struct intel_lpss *lpss = dev_get_drvdata(dev);
503
504 intel_lpss_init_dev(lpss);
505
506 return 0;
507}
508EXPORT_SYMBOL_GPL(intel_lpss_resume);
509
510static int __init intel_lpss_init(void)
511{
512 intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
513 return 0;
514}
515module_init(intel_lpss_init);
516
517static void __exit intel_lpss_exit(void)
518{
519 debugfs_remove(intel_lpss_debugfs);
520}
521module_exit(intel_lpss_exit);
522
523MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
524MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
525MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
526MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
527MODULE_DESCRIPTION("Intel LPSS core driver");
528MODULE_LICENSE("GPL v2");