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path: root/drivers/pci/controller/dwc/pci-imx6.c
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Diffstat (limited to 'drivers/pci/controller/dwc/pci-imx6.c')
-rw-r--r--drivers/pci/controller/dwc/pci-imx6.c871
1 files changed, 871 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
new file mode 100644
index 000000000000..80f604602783
--- /dev/null
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -0,0 +1,871 @@
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCIe host controller driver for Freescale i.MX6 SoCs
4 *
5 * Copyright (C) 2013 Kosagi
6 * http://www.kosagi.com
7 *
8 * Author: Sean Cross <xobs@kosagi.com>
9 */
10
11#include <linux/clk.h>
12#include <linux/delay.h>
13#include <linux/gpio.h>
14#include <linux/kernel.h>
15#include <linux/mfd/syscon.h>
16#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
17#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
18#include <linux/module.h>
19#include <linux/of_gpio.h>
20#include <linux/of_device.h>
21#include <linux/pci.h>
22#include <linux/platform_device.h>
23#include <linux/regmap.h>
24#include <linux/regulator/consumer.h>
25#include <linux/resource.h>
26#include <linux/signal.h>
27#include <linux/types.h>
28#include <linux/interrupt.h>
29#include <linux/reset.h>
30
31#include "pcie-designware.h"
32
33#define to_imx6_pcie(x) dev_get_drvdata((x)->dev)
34
35enum imx6_pcie_variants {
36 IMX6Q,
37 IMX6SX,
38 IMX6QP,
39 IMX7D,
40};
41
42struct imx6_pcie {
43 struct dw_pcie *pci;
44 int reset_gpio;
45 bool gpio_active_high;
46 struct clk *pcie_bus;
47 struct clk *pcie_phy;
48 struct clk *pcie_inbound_axi;
49 struct clk *pcie;
50 struct regmap *iomuxc_gpr;
51 struct reset_control *pciephy_reset;
52 struct reset_control *apps_reset;
53 enum imx6_pcie_variants variant;
54 u32 tx_deemph_gen1;
55 u32 tx_deemph_gen2_3p5db;
56 u32 tx_deemph_gen2_6db;
57 u32 tx_swing_full;
58 u32 tx_swing_low;
59 int link_gen;
60 struct regulator *vpcie;
61};
62
63/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
64#define PHY_PLL_LOCK_WAIT_MAX_RETRIES 2000
65#define PHY_PLL_LOCK_WAIT_USLEEP_MIN 50
66#define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200
67
68/* PCIe Root Complex registers (memory-mapped) */
69#define PCIE_RC_LCR 0x7c
70#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1
71#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2 0x2
72#define PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK 0xf
73
74#define PCIE_RC_LCSR 0x80
75
76/* PCIe Port Logic registers (memory-mapped) */
77#define PL_OFFSET 0x700
78#define PCIE_PL_PFLR (PL_OFFSET + 0x08)
79#define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16)
80#define PCIE_PL_PFLR_FORCE_LINK (1 << 15)
81#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
82#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
83#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING (1 << 29)
84#define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP (1 << 4)
85
86#define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
87#define PCIE_PHY_CTRL_DATA_LOC 0
88#define PCIE_PHY_CTRL_CAP_ADR_LOC 16
89#define PCIE_PHY_CTRL_CAP_DAT_LOC 17
90#define PCIE_PHY_CTRL_WR_LOC 18
91#define PCIE_PHY_CTRL_RD_LOC 19
92
93#define PCIE_PHY_STAT (PL_OFFSET + 0x110)
94#define PCIE_PHY_STAT_ACK_LOC 16
95
96#define PCIE_LINK_WIDTH_SPEED_CONTROL 0x80C
97#define PORT_LOGIC_SPEED_CHANGE (0x1 << 17)
98
99/* PHY registers (not memory-mapped) */
100#define PCIE_PHY_RX_ASIC_OUT 0x100D
101#define PCIE_PHY_RX_ASIC_OUT_VALID (1 << 0)
102
103#define PHY_RX_OVRD_IN_LO 0x1005
104#define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5)
105#define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3)
106
107static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, int exp_val)
108{
109 struct dw_pcie *pci = imx6_pcie->pci;
110 u32 val;
111 u32 max_iterations = 10;
112 u32 wait_counter = 0;
113
114 do {
115 val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT);
116 val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1;
117 wait_counter++;
118
119 if (val == exp_val)
120 return 0;
121
122 udelay(1);
123 } while (wait_counter < max_iterations);
124
125 return -ETIMEDOUT;
126}
127
128static int pcie_phy_wait_ack(struct imx6_pcie *imx6_pcie, int addr)
129{
130 struct dw_pcie *pci = imx6_pcie->pci;
131 u32 val;
132 int ret;
133
134 val = addr << PCIE_PHY_CTRL_DATA_LOC;
135 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
136
137 val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC);
138 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
139
140 ret = pcie_phy_poll_ack(imx6_pcie, 1);
141 if (ret)
142 return ret;
143
144 val = addr << PCIE_PHY_CTRL_DATA_LOC;
145 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
146
147 return pcie_phy_poll_ack(imx6_pcie, 0);
148}
149
150/* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
151static int pcie_phy_read(struct imx6_pcie *imx6_pcie, int addr, int *data)
152{
153 struct dw_pcie *pci = imx6_pcie->pci;
154 u32 val, phy_ctl;
155 int ret;
156
157 ret = pcie_phy_wait_ack(imx6_pcie, addr);
158 if (ret)
159 return ret;
160
161 /* assert Read signal */
162 phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC;
163 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, phy_ctl);
164
165 ret = pcie_phy_poll_ack(imx6_pcie, 1);
166 if (ret)
167 return ret;
168
169 val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT);
170 *data = val & 0xffff;
171
172 /* deassert Read signal */
173 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x00);
174
175 return pcie_phy_poll_ack(imx6_pcie, 0);
176}
177
178static int pcie_phy_write(struct imx6_pcie *imx6_pcie, int addr, int data)
179{
180 struct dw_pcie *pci = imx6_pcie->pci;
181 u32 var;
182 int ret;
183
184 /* write addr */
185 /* cap addr */
186 ret = pcie_phy_wait_ack(imx6_pcie, addr);
187 if (ret)
188 return ret;
189
190 var = data << PCIE_PHY_CTRL_DATA_LOC;
191 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
192
193 /* capture data */
194 var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC);
195 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
196
197 ret = pcie_phy_poll_ack(imx6_pcie, 1);
198 if (ret)
199 return ret;
200
201 /* deassert cap data */
202 var = data << PCIE_PHY_CTRL_DATA_LOC;
203 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
204
205 /* wait for ack de-assertion */
206 ret = pcie_phy_poll_ack(imx6_pcie, 0);
207 if (ret)
208 return ret;
209
210 /* assert wr signal */
211 var = 0x1 << PCIE_PHY_CTRL_WR_LOC;
212 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
213
214 /* wait for ack */
215 ret = pcie_phy_poll_ack(imx6_pcie, 1);
216 if (ret)
217 return ret;
218
219 /* deassert wr signal */
220 var = data << PCIE_PHY_CTRL_DATA_LOC;
221 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
222
223 /* wait for ack de-assertion */
224 ret = pcie_phy_poll_ack(imx6_pcie, 0);
225 if (ret)
226 return ret;
227
228 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x0);
229
230 return 0;
231}
232
233static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie)
234{
235 u32 tmp;
236
237 pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
238 tmp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN |
239 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
240 pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
241
242 usleep_range(2000, 3000);
243
244 pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
245 tmp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN |
246 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
247 pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
248}
249
250/* Added for PCI abort handling */
251static int imx6q_pcie_abort_handler(unsigned long addr,
252 unsigned int fsr, struct pt_regs *regs)
253{
254 unsigned long pc = instruction_pointer(regs);
255 unsigned long instr = *(unsigned long *)pc;
256 int reg = (instr >> 12) & 15;
257
258 /*
259 * If the instruction being executed was a read,
260 * make it look like it read all-ones.
261 */
262 if ((instr & 0x0c100000) == 0x04100000) {
263 unsigned long val;
264
265 if (instr & 0x00400000)
266 val = 255;
267 else
268 val = -1;
269
270 regs->uregs[reg] = val;
271 regs->ARM_pc += 4;
272 return 0;
273 }
274
275 if ((instr & 0x0e100090) == 0x00100090) {
276 regs->uregs[reg] = -1;
277 regs->ARM_pc += 4;
278 return 0;
279 }
280
281 return 1;
282}
283
284static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
285{
286 struct device *dev = imx6_pcie->pci->dev;
287
288 switch (imx6_pcie->variant) {
289 case IMX7D:
290 reset_control_assert(imx6_pcie->pciephy_reset);
291 reset_control_assert(imx6_pcie->apps_reset);
292 break;
293 case IMX6SX:
294 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
295 IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
296 IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
297 /* Force PCIe PHY reset */
298 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
299 IMX6SX_GPR5_PCIE_BTNRST_RESET,
300 IMX6SX_GPR5_PCIE_BTNRST_RESET);
301 break;
302 case IMX6QP:
303 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
304 IMX6Q_GPR1_PCIE_SW_RST,
305 IMX6Q_GPR1_PCIE_SW_RST);
306 break;
307 case IMX6Q:
308 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
309 IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
310 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
311 IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
312 break;
313 }
314
315 if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
316 int ret = regulator_disable(imx6_pcie->vpcie);
317
318 if (ret)
319 dev_err(dev, "failed to disable vpcie regulator: %d\n",
320 ret);
321 }
322}
323
324static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
325{
326 struct dw_pcie *pci = imx6_pcie->pci;
327 struct device *dev = pci->dev;
328 int ret = 0;
329
330 switch (imx6_pcie->variant) {
331 case IMX6SX:
332 ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
333 if (ret) {
334 dev_err(dev, "unable to enable pcie_axi clock\n");
335 break;
336 }
337
338 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
339 IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
340 break;
341 case IMX6QP: /* FALLTHROUGH */
342 case IMX6Q:
343 /* power up core phy and enable ref clock */
344 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
345 IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
346 /*
347 * the async reset input need ref clock to sync internally,
348 * when the ref clock comes after reset, internal synced
349 * reset time is too short, cannot meet the requirement.
350 * add one ~10us delay here.
351 */
352 udelay(10);
353 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
354 IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
355 break;
356 case IMX7D:
357 break;
358 }
359
360 return ret;
361}
362
363static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
364{
365 u32 val;
366 unsigned int retries;
367 struct device *dev = imx6_pcie->pci->dev;
368
369 for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) {
370 regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val);
371
372 if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED)
373 return;
374
375 usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN,
376 PHY_PLL_LOCK_WAIT_USLEEP_MAX);
377 }
378
379 dev_err(dev, "PCIe PLL lock timeout\n");
380}
381
382static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
383{
384 struct dw_pcie *pci = imx6_pcie->pci;
385 struct device *dev = pci->dev;
386 int ret;
387
388 if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
389 ret = regulator_enable(imx6_pcie->vpcie);
390 if (ret) {
391 dev_err(dev, "failed to enable vpcie regulator: %d\n",
392 ret);
393 return;
394 }
395 }
396
397 ret = clk_prepare_enable(imx6_pcie->pcie_phy);
398 if (ret) {
399 dev_err(dev, "unable to enable pcie_phy clock\n");
400 goto err_pcie_phy;
401 }
402
403 ret = clk_prepare_enable(imx6_pcie->pcie_bus);
404 if (ret) {
405 dev_err(dev, "unable to enable pcie_bus clock\n");
406 goto err_pcie_bus;
407 }
408
409 ret = clk_prepare_enable(imx6_pcie->pcie);
410 if (ret) {
411 dev_err(dev, "unable to enable pcie clock\n");
412 goto err_pcie;
413 }
414
415 ret = imx6_pcie_enable_ref_clk(imx6_pcie);
416 if (ret) {
417 dev_err(dev, "unable to enable pcie ref clock\n");
418 goto err_ref_clk;
419 }
420
421 /* allow the clocks to stabilize */
422 usleep_range(200, 500);
423
424 /* Some boards don't have PCIe reset GPIO. */
425 if (gpio_is_valid(imx6_pcie->reset_gpio)) {
426 gpio_set_value_cansleep(imx6_pcie->reset_gpio,
427 imx6_pcie->gpio_active_high);
428 msleep(100);
429 gpio_set_value_cansleep(imx6_pcie->reset_gpio,
430 !imx6_pcie->gpio_active_high);
431 }
432
433 switch (imx6_pcie->variant) {
434 case IMX7D:
435 reset_control_deassert(imx6_pcie->pciephy_reset);
436 imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
437 break;
438 case IMX6SX:
439 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
440 IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
441 break;
442 case IMX6QP:
443 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
444 IMX6Q_GPR1_PCIE_SW_RST, 0);
445
446 usleep_range(200, 500);
447 break;
448 case IMX6Q: /* Nothing to do */
449 break;
450 }
451
452 return;
453
454err_ref_clk:
455 clk_disable_unprepare(imx6_pcie->pcie);
456err_pcie:
457 clk_disable_unprepare(imx6_pcie->pcie_bus);
458err_pcie_bus:
459 clk_disable_unprepare(imx6_pcie->pcie_phy);
460err_pcie_phy:
461 if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
462 ret = regulator_disable(imx6_pcie->vpcie);
463 if (ret)
464 dev_err(dev, "failed to disable vpcie regulator: %d\n",
465 ret);
466 }
467}
468
469static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
470{
471 switch (imx6_pcie->variant) {
472 case IMX7D:
473 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
474 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
475 break;
476 case IMX6SX:
477 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
478 IMX6SX_GPR12_PCIE_RX_EQ_MASK,
479 IMX6SX_GPR12_PCIE_RX_EQ_2);
480 /* FALLTHROUGH */
481 default:
482 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
483 IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
484
485 /* configure constant input signal to the pcie ctrl and phy */
486 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
487 IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
488
489 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
490 IMX6Q_GPR8_TX_DEEMPH_GEN1,
491 imx6_pcie->tx_deemph_gen1 << 0);
492 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
493 IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
494 imx6_pcie->tx_deemph_gen2_3p5db << 6);
495 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
496 IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
497 imx6_pcie->tx_deemph_gen2_6db << 12);
498 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
499 IMX6Q_GPR8_TX_SWING_FULL,
500 imx6_pcie->tx_swing_full << 18);
501 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
502 IMX6Q_GPR8_TX_SWING_LOW,
503 imx6_pcie->tx_swing_low << 25);
504 break;
505 }
506
507 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
508 IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
509}
510
511static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie)
512{
513 struct dw_pcie *pci = imx6_pcie->pci;
514 struct device *dev = pci->dev;
515
516 /* check if the link is up or not */
517 if (!dw_pcie_wait_for_link(pci))
518 return 0;
519
520 dev_dbg(dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
521 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
522 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
523 return -ETIMEDOUT;
524}
525
526static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
527{
528 struct dw_pcie *pci = imx6_pcie->pci;
529 struct device *dev = pci->dev;
530 u32 tmp;
531 unsigned int retries;
532
533 for (retries = 0; retries < 200; retries++) {
534 tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
535 /* Test if the speed change finished. */
536 if (!(tmp & PORT_LOGIC_SPEED_CHANGE))
537 return 0;
538 usleep_range(100, 1000);
539 }
540
541 dev_err(dev, "Speed change timeout\n");
542 return -EINVAL;
543}
544
545static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
546{
547 struct dw_pcie *pci = imx6_pcie->pci;
548 struct device *dev = pci->dev;
549 u32 tmp;
550 int ret;
551
552 /*
553 * Force Gen1 operation when starting the link. In case the link is
554 * started in Gen2 mode, there is a possibility the devices on the
555 * bus will not be detected at all. This happens with PCIe switches.
556 */
557 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
558 tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
559 tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
560 dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
561
562 /* Start LTSSM. */
563 if (imx6_pcie->variant == IMX7D)
564 reset_control_deassert(imx6_pcie->apps_reset);
565 else
566 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
567 IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
568
569 ret = imx6_pcie_wait_for_link(imx6_pcie);
570 if (ret)
571 goto err_reset_phy;
572
573 if (imx6_pcie->link_gen == 2) {
574 /* Allow Gen2 mode after the link is up. */
575 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
576 tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
577 tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
578 dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
579
580 /*
581 * Start Directed Speed Change so the best possible
582 * speed both link partners support can be negotiated.
583 */
584 tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
585 tmp |= PORT_LOGIC_SPEED_CHANGE;
586 dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
587
588 if (imx6_pcie->variant != IMX7D) {
589 /*
590 * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
591 * from i.MX6 family when no link speed transition
592 * occurs and we go Gen1 -> yep, Gen1. The difference
593 * is that, in such case, it will not be cleared by HW
594 * which will cause the following code to report false
595 * failure.
596 */
597
598 ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
599 if (ret) {
600 dev_err(dev, "Failed to bring link up!\n");
601 goto err_reset_phy;
602 }
603 }
604
605 /* Make sure link training is finished as well! */
606 ret = imx6_pcie_wait_for_link(imx6_pcie);
607 if (ret) {
608 dev_err(dev, "Failed to bring link up!\n");
609 goto err_reset_phy;
610 }
611 } else {
612 dev_info(dev, "Link: Gen2 disabled\n");
613 }
614
615 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
616 dev_info(dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf);
617 return 0;
618
619err_reset_phy:
620 dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
621 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
622 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
623 imx6_pcie_reset_phy(imx6_pcie);
624 return ret;
625}
626
627static int imx6_pcie_host_init(struct pcie_port *pp)
628{
629 struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
630 struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci);
631
632 imx6_pcie_assert_core_reset(imx6_pcie);
633 imx6_pcie_init_phy(imx6_pcie);
634 imx6_pcie_deassert_core_reset(imx6_pcie);
635 dw_pcie_setup_rc(pp);
636 imx6_pcie_establish_link(imx6_pcie);
637
638 if (IS_ENABLED(CONFIG_PCI_MSI))
639 dw_pcie_msi_init(pp);
640
641 return 0;
642}
643
644static int imx6_pcie_link_up(struct dw_pcie *pci)
645{
646 return dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1) &
647 PCIE_PHY_DEBUG_R1_XMLH_LINK_UP;
648}
649
650static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
651 .host_init = imx6_pcie_host_init,
652};
653
654static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
655 struct platform_device *pdev)
656{
657 struct dw_pcie *pci = imx6_pcie->pci;
658 struct pcie_port *pp = &pci->pp;
659 struct device *dev = &pdev->dev;
660 int ret;
661
662 if (IS_ENABLED(CONFIG_PCI_MSI)) {
663 pp->msi_irq = platform_get_irq_byname(pdev, "msi");
664 if (pp->msi_irq <= 0) {
665 dev_err(dev, "failed to get MSI irq\n");
666 return -ENODEV;
667 }
668 }
669
670 pp->root_bus_nr = -1;
671 pp->ops = &imx6_pcie_host_ops;
672
673 ret = dw_pcie_host_init(pp);
674 if (ret) {
675 dev_err(dev, "failed to initialize host\n");
676 return ret;
677 }
678
679 return 0;
680}
681
682static const struct dw_pcie_ops dw_pcie_ops = {
683 .link_up = imx6_pcie_link_up,
684};
685
686static int imx6_pcie_probe(struct platform_device *pdev)
687{
688 struct device *dev = &pdev->dev;
689 struct dw_pcie *pci;
690 struct imx6_pcie *imx6_pcie;
691 struct resource *dbi_base;
692 struct device_node *node = dev->of_node;
693 int ret;
694
695 imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL);
696 if (!imx6_pcie)
697 return -ENOMEM;
698
699 pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
700 if (!pci)
701 return -ENOMEM;
702
703 pci->dev = dev;
704 pci->ops = &dw_pcie_ops;
705
706 imx6_pcie->pci = pci;
707 imx6_pcie->variant =
708 (enum imx6_pcie_variants)of_device_get_match_data(dev);
709
710 dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
711 pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
712 if (IS_ERR(pci->dbi_base))
713 return PTR_ERR(pci->dbi_base);
714
715 /* Fetch GPIOs */
716 imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0);
717 imx6_pcie->gpio_active_high = of_property_read_bool(node,
718 "reset-gpio-active-high");
719 if (gpio_is_valid(imx6_pcie->reset_gpio)) {
720 ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio,
721 imx6_pcie->gpio_active_high ?
722 GPIOF_OUT_INIT_HIGH :
723 GPIOF_OUT_INIT_LOW,
724 "PCIe reset");
725 if (ret) {
726 dev_err(dev, "unable to get reset gpio\n");
727 return ret;
728 }
729 } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) {
730 return imx6_pcie->reset_gpio;
731 }
732
733 /* Fetch clocks */
734 imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
735 if (IS_ERR(imx6_pcie->pcie_phy)) {
736 dev_err(dev, "pcie_phy clock source missing or invalid\n");
737 return PTR_ERR(imx6_pcie->pcie_phy);
738 }
739
740 imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
741 if (IS_ERR(imx6_pcie->pcie_bus)) {
742 dev_err(dev, "pcie_bus clock source missing or invalid\n");
743 return PTR_ERR(imx6_pcie->pcie_bus);
744 }
745
746 imx6_pcie->pcie = devm_clk_get(dev, "pcie");
747 if (IS_ERR(imx6_pcie->pcie)) {
748 dev_err(dev, "pcie clock source missing or invalid\n");
749 return PTR_ERR(imx6_pcie->pcie);
750 }
751
752 switch (imx6_pcie->variant) {
753 case IMX6SX:
754 imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
755 "pcie_inbound_axi");
756 if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
757 dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
758 return PTR_ERR(imx6_pcie->pcie_inbound_axi);
759 }
760 break;
761 case IMX7D:
762 imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev,
763 "pciephy");
764 if (IS_ERR(imx6_pcie->pciephy_reset)) {
765 dev_err(dev, "Failed to get PCIEPHY reset control\n");
766 return PTR_ERR(imx6_pcie->pciephy_reset);
767 }
768
769 imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
770 "apps");
771 if (IS_ERR(imx6_pcie->apps_reset)) {
772 dev_err(dev, "Failed to get PCIE APPS reset control\n");
773 return PTR_ERR(imx6_pcie->apps_reset);
774 }
775 break;
776 default:
777 break;
778 }
779
780 /* Grab GPR config register range */
781 imx6_pcie->iomuxc_gpr =
782 syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
783 if (IS_ERR(imx6_pcie->iomuxc_gpr)) {
784 dev_err(dev, "unable to find iomuxc registers\n");
785 return PTR_ERR(imx6_pcie->iomuxc_gpr);
786 }
787
788 /* Grab PCIe PHY Tx Settings */
789 if (of_property_read_u32(node, "fsl,tx-deemph-gen1",
790 &imx6_pcie->tx_deemph_gen1))
791 imx6_pcie->tx_deemph_gen1 = 0;
792
793 if (of_property_read_u32(node, "fsl,tx-deemph-gen2-3p5db",
794 &imx6_pcie->tx_deemph_gen2_3p5db))
795 imx6_pcie->tx_deemph_gen2_3p5db = 0;
796
797 if (of_property_read_u32(node, "fsl,tx-deemph-gen2-6db",
798 &imx6_pcie->tx_deemph_gen2_6db))
799 imx6_pcie->tx_deemph_gen2_6db = 20;
800
801 if (of_property_read_u32(node, "fsl,tx-swing-full",
802 &imx6_pcie->tx_swing_full))
803 imx6_pcie->tx_swing_full = 127;
804
805 if (of_property_read_u32(node, "fsl,tx-swing-low",
806 &imx6_pcie->tx_swing_low))
807 imx6_pcie->tx_swing_low = 127;
808
809 /* Limit link speed */
810 ret = of_property_read_u32(node, "fsl,max-link-speed",
811 &imx6_pcie->link_gen);
812 if (ret)
813 imx6_pcie->link_gen = 1;
814
815 imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
816 if (IS_ERR(imx6_pcie->vpcie)) {
817 if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
818 return -EPROBE_DEFER;
819 imx6_pcie->vpcie = NULL;
820 }
821
822 platform_set_drvdata(pdev, imx6_pcie);
823
824 ret = imx6_add_pcie_port(imx6_pcie, pdev);
825 if (ret < 0)
826 return ret;
827
828 return 0;
829}
830
831static void imx6_pcie_shutdown(struct platform_device *pdev)
832{
833 struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev);
834
835 /* bring down link, so bootloader gets clean state in case of reboot */
836 imx6_pcie_assert_core_reset(imx6_pcie);
837}
838
839static const struct of_device_id imx6_pcie_of_match[] = {
840 { .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, },
841 { .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
842 { .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
843 { .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, },
844 {},
845};
846
847static struct platform_driver imx6_pcie_driver = {
848 .driver = {
849 .name = "imx6q-pcie",
850 .of_match_table = imx6_pcie_of_match,
851 .suppress_bind_attrs = true,
852 },
853 .probe = imx6_pcie_probe,
854 .shutdown = imx6_pcie_shutdown,
855};
856
857static int __init imx6_pcie_init(void)
858{
859 /*
860 * Since probe() can be deferred we need to make sure that
861 * hook_fault_code is not called after __init memory is freed
862 * by kernel and since imx6q_pcie_abort_handler() is a no-op,
863 * we can install the handler here without risking it
864 * accessing some uninitialized driver state.
865 */
866 hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
867 "external abort on non-linefetch");
868
869 return platform_driver_register(&imx6_pcie_driver);
870}
871device_initcall(imx6_pcie_init);
generated by cgit v1.2.2 (git 2.25.0) at 2025-06-03 02:57:19 -0400