1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Intel Sunrisepoint LPSS core support.
4 *
5 * Copyright (C) 2015, Intel Corporation
6 *
7 * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
8 * Mika Westerberg <mika.westerberg@linux.intel.com>
9 * Heikki Krogerus <heikki.krogerus@linux.intel.com>
10 * Jarkko Nikula <jarkko.nikula@linux.intel.com>
11 */
12
13#include <linux/array_size.h>
14#include <linux/bits.h>
15#include <linux/clkdev.h>
16#include <linux/clk.h>
17#include <linux/clk-provider.h>
18#include <linux/debugfs.h>
19#include <linux/device.h>
20#include <linux/err.h>
21#include <linux/gfp_types.h>
22#include <linux/idr.h>
23#include <linux/io.h>
24#include <linux/ioport.h>
25#include <linux/mfd/core.h>
26#include <linux/module.h>
27#include <linux/pm.h>
28#include <linux/pm_qos.h>
29#include <linux/pm_runtime.h>
30#include <linux/sprintf.h>
31#include <linux/types.h>
32
33#include <linux/io-64-nonatomic-lo-hi.h>
34
35#include <linux/dma/idma64.h>
36
37#include "intel-lpss.h"
38
39struct dentry;
40
41#define LPSS_DEV_OFFSET 0x000
42#define LPSS_DEV_SIZE 0x200
43#define LPSS_PRIV_OFFSET 0x200
44#define LPSS_PRIV_SIZE 0x100
45#define LPSS_PRIV_REG_COUNT (LPSS_PRIV_SIZE / 4)
46#define LPSS_IDMA64_OFFSET 0x800
47#define LPSS_IDMA64_SIZE 0x800
48
49/* Offsets from lpss->priv */
50#define LPSS_PRIV_RESETS 0x04
51#define LPSS_PRIV_RESETS_IDMA BIT(2)
52#define LPSS_PRIV_RESETS_FUNC 0x3
53
54#define LPSS_PRIV_ACTIVELTR 0x10
55#define LPSS_PRIV_IDLELTR 0x14
56
57#define LPSS_PRIV_LTR_REQ BIT(15)
58#define LPSS_PRIV_LTR_SCALE_MASK GENMASK(11, 10)
59#define LPSS_PRIV_LTR_SCALE_1US (2 << 10)
60#define LPSS_PRIV_LTR_SCALE_32US (3 << 10)
61#define LPSS_PRIV_LTR_VALUE_MASK GENMASK(9, 0)
62
63#define LPSS_PRIV_SSP_REG 0x20
64#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN BIT(0)
65
66#define LPSS_PRIV_REMAP_ADDR 0x40
67
68#define LPSS_PRIV_CAPS 0xfc
69#define LPSS_PRIV_CAPS_NO_IDMA BIT(8)
70#define LPSS_PRIV_CAPS_TYPE_MASK GENMASK(7, 4)
71#define LPSS_PRIV_CAPS_TYPE_SHIFT 4
72
73/* This matches the type field in CAPS register */
74enum intel_lpss_dev_type {
75 LPSS_DEV_I2C = 0,
76 LPSS_DEV_UART,
77 LPSS_DEV_SPI,
78};
79
80struct intel_lpss {
81 const struct intel_lpss_platform_info *info;
82 enum intel_lpss_dev_type type;
83 struct clk *clk;
84 struct clk_lookup *clock;
85 struct mfd_cell *cell;
86 struct device *dev;
87 void __iomem *priv;
88 u32 priv_ctx[LPSS_PRIV_REG_COUNT];
89 int devid;
90 u32 caps;
91 u32 active_ltr;
92 u32 idle_ltr;
93 struct dentry *debugfs;
94};
95
96static const struct resource intel_lpss_dev_resources[] = {
97 DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
98 DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
99 DEFINE_RES_IRQ(0),
100};
101
102static const struct resource intel_lpss_idma64_resources[] = {
103 DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
104 DEFINE_RES_IRQ(0),
105};
106
107/*
108 * Cells needs to be ordered so that the iDMA is created first. This is
109 * because we need to be sure the DMA is available when the host controller
110 * driver is probed.
111 */
112static const struct mfd_cell intel_lpss_idma64_cell = {
113 .name = LPSS_IDMA64_DRIVER_NAME,
114 .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
115 .resources = intel_lpss_idma64_resources,
116};
117
118static const struct mfd_cell intel_lpss_i2c_cell = {
119 .name = "i2c_designware",
120 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
121 .resources = intel_lpss_dev_resources,
122};
123
124static const struct mfd_cell intel_lpss_uart_cell = {
125 .name = "dw-apb-uart",
126 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
127 .resources = intel_lpss_dev_resources,
128};
129
130static const struct mfd_cell intel_lpss_spi_cell = {
131 .name = "pxa2xx-spi",
132 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
133 .resources = intel_lpss_dev_resources,
134};
135
136static DEFINE_IDA(intel_lpss_devid_ida);
137static struct dentry *intel_lpss_debugfs;
138
139static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
140{
141 lpss->active_ltr = readl(addr: lpss->priv + LPSS_PRIV_ACTIVELTR);
142 lpss->idle_ltr = readl(addr: lpss->priv + LPSS_PRIV_IDLELTR);
143}
144
145static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
146{
147 struct dentry *dir;
148
149 dir = debugfs_create_dir(name: dev_name(dev: lpss->dev), parent: intel_lpss_debugfs);
150 if (IS_ERR(ptr: dir))
151 return PTR_ERR(ptr: dir);
152
153 /* Cache the values into lpss structure */
154 intel_lpss_cache_ltr(lpss);
155
156 debugfs_create_x32(name: "capabilities", S_IRUGO, parent: dir, value: &lpss->caps);
157 debugfs_create_x32(name: "active_ltr", S_IRUGO, parent: dir, value: &lpss->active_ltr);
158 debugfs_create_x32(name: "idle_ltr", S_IRUGO, parent: dir, value: &lpss->idle_ltr);
159
160 lpss->debugfs = dir;
161 return 0;
162}
163
164static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
165{
166 debugfs_remove_recursive(dentry: lpss->debugfs);
167}
168
169static void intel_lpss_ltr_set(struct device *dev, s32 val)
170{
171 struct intel_lpss *lpss = dev_get_drvdata(dev);
172 u32 ltr;
173
174 /*
175 * Program latency tolerance (LTR) accordingly what has been asked
176 * by the PM QoS layer or disable it in case we were passed
177 * negative value or PM_QOS_LATENCY_ANY.
178 */
179 ltr = readl(addr: lpss->priv + LPSS_PRIV_ACTIVELTR);
180
181 if (val == PM_QOS_LATENCY_ANY || val < 0) {
182 ltr &= ~LPSS_PRIV_LTR_REQ;
183 } else {
184 ltr |= LPSS_PRIV_LTR_REQ;
185 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
186 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
187
188 if (val > LPSS_PRIV_LTR_VALUE_MASK)
189 ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
190 else
191 ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
192 }
193
194 if (ltr == lpss->active_ltr)
195 return;
196
197 writel(val: ltr, addr: lpss->priv + LPSS_PRIV_ACTIVELTR);
198 writel(val: ltr, addr: lpss->priv + LPSS_PRIV_IDLELTR);
199
200 /* Cache the values into lpss structure */
201 intel_lpss_cache_ltr(lpss);
202}
203
204static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
205{
206 lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
207 dev_pm_qos_expose_latency_tolerance(dev: lpss->dev);
208}
209
210static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
211{
212 dev_pm_qos_hide_latency_tolerance(dev: lpss->dev);
213 lpss->dev->power.set_latency_tolerance = NULL;
214}
215
216static int intel_lpss_assign_devs(struct intel_lpss *lpss)
217{
218 const struct mfd_cell *cell;
219 unsigned int type;
220
221 type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
222 type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
223
224 switch (type) {
225 case LPSS_DEV_I2C:
226 cell = &intel_lpss_i2c_cell;
227 break;
228 case LPSS_DEV_UART:
229 cell = &intel_lpss_uart_cell;
230 break;
231 case LPSS_DEV_SPI:
232 cell = &intel_lpss_spi_cell;
233 break;
234 default:
235 return -ENODEV;
236 }
237
238 lpss->cell = devm_kmemdup(dev: lpss->dev, src: cell, len: sizeof(*cell), GFP_KERNEL);
239 if (!lpss->cell)
240 return -ENOMEM;
241
242 lpss->type = type;
243
244 return 0;
245}
246
247static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
248{
249 return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
250}
251
252static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
253{
254 resource_size_t addr = lpss->info->mem->start;
255
256 lo_hi_writeq(val: addr, addr: lpss->priv + LPSS_PRIV_REMAP_ADDR);
257}
258
259static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
260{
261 u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
262
263 /* Bring out the device from reset */
264 writel(val: value, addr: lpss->priv + LPSS_PRIV_RESETS);
265}
266
267static void intel_lpss_init_dev(const struct intel_lpss *lpss)
268{
269 u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
270
271 /* Set the device in reset state */
272 writel(val: 0, addr: lpss->priv + LPSS_PRIV_RESETS);
273
274 intel_lpss_deassert_reset(lpss);
275
276 intel_lpss_set_remap_addr(lpss);
277
278 if (!intel_lpss_has_idma(lpss))
279 return;
280
281 /* Make sure that SPI multiblock DMA transfers are re-enabled */
282 if (lpss->type == LPSS_DEV_SPI)
283 writel(val: value, addr: 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 int ret;
304
305 snprintf(buf: name, size: sizeof(name), fmt: "%s-enable", devname);
306 tmp = clk_register_gate(NULL, name, parent_name: __clk_get_name(clk: tmp), flags: 0,
307 reg: lpss->priv, bit_idx: 0, clk_gate_flags: 0, NULL);
308 if (IS_ERR(ptr: tmp))
309 return PTR_ERR(ptr: tmp);
310
311 snprintf(buf: name, size: sizeof(name), fmt: "%s-div", devname);
312 tmp = clk_register_fractional_divider(NULL, name, parent_name: __clk_get_name(clk: tmp),
313 flags: 0, reg: lpss->priv, mshift: 1, mwidth: 15, nshift: 16, nwidth: 15,
314 CLK_FRAC_DIVIDER_POWER_OF_TWO_PS,
315 NULL);
316 if (IS_ERR(ptr: tmp))
317 return PTR_ERR(ptr: tmp);
318 *clk = tmp;
319
320 if (lpss->info->quirks & QUIRK_CLOCK_DIVIDER_UNITY) {
321 ret = clk_set_rate(clk: tmp, rate: lpss->info->clk_rate);
322 if (ret)
323 return ret;
324 }
325
326 snprintf(buf: name, size: sizeof(name), fmt: "%s-update", devname);
327 tmp = clk_register_gate(NULL, name, parent_name: __clk_get_name(clk: tmp),
328 CLK_SET_RATE_PARENT, reg: lpss->priv, bit_idx: 31, clk_gate_flags: 0, NULL);
329 if (IS_ERR(ptr: tmp))
330 return PTR_ERR(ptr: tmp);
331 *clk = tmp;
332
333 return 0;
334}
335
336static int intel_lpss_register_clock(struct intel_lpss *lpss)
337{
338 const struct mfd_cell *cell = lpss->cell;
339 struct clk *clk;
340 char devname[24];
341 int ret;
342
343 if (!lpss->info->clk_rate)
344 return 0;
345
346 /* Root clock */
347 clk = clk_register_fixed_rate(NULL, name: dev_name(dev: lpss->dev), NULL, flags: 0,
348 fixed_rate: lpss->info->clk_rate);
349 if (IS_ERR(ptr: clk))
350 return PTR_ERR(ptr: clk);
351
352 snprintf(buf: devname, size: sizeof(devname), fmt: "%s.%d", cell->name, lpss->devid);
353
354 /*
355 * Support for clock divider only if it has some preset value.
356 * Otherwise we assume that the divider is not used.
357 */
358 if (lpss->type != LPSS_DEV_I2C) {
359 ret = intel_lpss_register_clock_divider(lpss, devname, clk: &clk);
360 if (ret)
361 goto err_clk_register;
362 }
363
364 ret = -ENOMEM;
365
366 /* Clock for the host controller */
367 lpss->clock = clkdev_create(clk, con_id: lpss->info->clk_con_id, dev_fmt: "%s", devname);
368 if (!lpss->clock)
369 goto err_clk_register;
370
371 lpss->clk = clk;
372
373 return 0;
374
375err_clk_register:
376 intel_lpss_unregister_clock_tree(clk);
377
378 return ret;
379}
380
381static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
382{
383 if (IS_ERR_OR_NULL(ptr: lpss->clk))
384 return;
385
386 clkdev_drop(cl: lpss->clock);
387 intel_lpss_unregister_clock_tree(clk: lpss->clk);
388}
389
390int intel_lpss_probe(struct device *dev,
391 const struct intel_lpss_platform_info *info)
392{
393 struct intel_lpss *lpss;
394 int ret;
395
396 if (!info || !info->mem)
397 return -EINVAL;
398
399 if (info->irq < 0)
400 return info->irq;
401
402 lpss = devm_kzalloc(dev, size: sizeof(*lpss), GFP_KERNEL);
403 if (!lpss)
404 return -ENOMEM;
405
406 lpss->priv = devm_ioremap_uc(dev, offset: info->mem->start + LPSS_PRIV_OFFSET,
407 LPSS_PRIV_SIZE);
408 if (!lpss->priv)
409 return -ENOMEM;
410
411 lpss->info = info;
412 lpss->dev = dev;
413 lpss->caps = readl(addr: lpss->priv + LPSS_PRIV_CAPS);
414
415 dev_set_drvdata(dev, data: lpss);
416
417 ret = intel_lpss_assign_devs(lpss);
418 if (ret)
419 return ret;
420
421 lpss->cell->swnode = info->swnode;
422 lpss->cell->ignore_resource_conflicts = info->quirks & QUIRK_IGNORE_RESOURCE_CONFLICTS;
423
424 intel_lpss_init_dev(lpss);
425
426 lpss->devid = ida_alloc(ida: &intel_lpss_devid_ida, GFP_KERNEL);
427 if (lpss->devid < 0)
428 return lpss->devid;
429
430 ret = intel_lpss_register_clock(lpss);
431 if (ret)
432 goto err_clk_register;
433
434 intel_lpss_ltr_expose(lpss);
435
436 ret = intel_lpss_debugfs_add(lpss);
437 if (ret)
438 dev_warn(dev, "Failed to create debugfs entries\n");
439
440 if (intel_lpss_has_idma(lpss)) {
441 ret = mfd_add_devices(parent: dev, id: lpss->devid, cells: &intel_lpss_idma64_cell,
442 n_devs: 1, mem_base: info->mem, irq_base: info->irq, NULL);
443 if (ret)
444 dev_warn(dev, "Failed to add %s, fallback to PIO\n",
445 LPSS_IDMA64_DRIVER_NAME);
446 }
447
448 ret = mfd_add_devices(parent: dev, id: lpss->devid, cells: lpss->cell,
449 n_devs: 1, mem_base: info->mem, irq_base: info->irq, NULL);
450 if (ret)
451 goto err_remove_ltr;
452
453 dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);
454
455 return 0;
456
457err_remove_ltr:
458 intel_lpss_debugfs_remove(lpss);
459 intel_lpss_ltr_hide(lpss);
460 intel_lpss_unregister_clock(lpss);
461
462err_clk_register:
463 ida_free(&intel_lpss_devid_ida, id: lpss->devid);
464
465 return ret;
466}
467EXPORT_SYMBOL_NS_GPL(intel_lpss_probe, "INTEL_LPSS");
468
469void intel_lpss_remove(struct device *dev)
470{
471 struct intel_lpss *lpss = dev_get_drvdata(dev);
472
473 mfd_remove_devices(parent: dev);
474 intel_lpss_debugfs_remove(lpss);
475 intel_lpss_ltr_hide(lpss);
476 intel_lpss_unregister_clock(lpss);
477 ida_free(&intel_lpss_devid_ida, id: lpss->devid);
478}
479EXPORT_SYMBOL_NS_GPL(intel_lpss_remove, "INTEL_LPSS");
480
481static int resume_lpss_device(struct device *dev, void *data)
482{
483 if (!dev_pm_smart_suspend(dev))
484 pm_runtime_resume(dev);
485
486 return 0;
487}
488
489static int intel_lpss_prepare(struct device *dev)
490{
491 /*
492 * Resume both child devices before entering system sleep. This
493 * ensures that they are in proper state before they get suspended.
494 */
495 device_for_each_child_reverse(parent: dev, NULL, fn: resume_lpss_device);
496 return 0;
497}
498
499static int intel_lpss_suspend(struct device *dev)
500{
501 struct intel_lpss *lpss = dev_get_drvdata(dev);
502 unsigned int i;
503
504 /* Save device context */
505 for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
506 lpss->priv_ctx[i] = readl(addr: lpss->priv + i * 4);
507
508 /*
509 * If the device type is not UART, then put the controller into
510 * reset. UART cannot be put into reset since S3/S0ix fail when
511 * no_console_suspend flag is enabled.
512 */
513 if (lpss->type != LPSS_DEV_UART)
514 writel(val: 0, addr: lpss->priv + LPSS_PRIV_RESETS);
515
516 return 0;
517}
518
519static int intel_lpss_resume(struct device *dev)
520{
521 struct intel_lpss *lpss = dev_get_drvdata(dev);
522 unsigned int i;
523
524 intel_lpss_deassert_reset(lpss);
525
526 /* Restore device context */
527 for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
528 writel(val: lpss->priv_ctx[i], addr: lpss->priv + i * 4);
529
530 return 0;
531}
532
533EXPORT_NS_GPL_DEV_PM_OPS(intel_lpss_pm_ops, INTEL_LPSS) = {
534 .prepare = pm_sleep_ptr(&intel_lpss_prepare),
535 LATE_SYSTEM_SLEEP_PM_OPS(intel_lpss_suspend, intel_lpss_resume)
536 RUNTIME_PM_OPS(intel_lpss_suspend, intel_lpss_resume, NULL)
537};
538
539static int __init intel_lpss_init(void)
540{
541 intel_lpss_debugfs = debugfs_create_dir(name: "intel_lpss", NULL);
542 return 0;
543}
544module_init(intel_lpss_init);
545
546static void __exit intel_lpss_exit(void)
547{
548 ida_destroy(ida: &intel_lpss_devid_ida);
549 debugfs_remove(dentry: intel_lpss_debugfs);
550}
551module_exit(intel_lpss_exit);
552
553MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
554MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
555MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
556MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
557MODULE_DESCRIPTION("Intel LPSS core driver");
558MODULE_LICENSE("GPL v2");
559/*
560 * Ensure the DMA driver is loaded before the host controller device appears,
561 * so that the host controller driver can request its DMA channels as early
562 * as possible.
563 *
564 * If the DMA module is not there that's OK as well.
565 */
566MODULE_SOFTDEP("pre: platform:" LPSS_IDMA64_DRIVER_NAME);
567

source code of linux/drivers/mfd/intel-lpss.c