1 // SPDX-License-Identifier: GPL-2.0
3 * PCIe host controller driver for Freescale i.MX6 SoCs
5 * Copyright (C) 2013 Kosagi
6 * http://www.kosagi.com
11 #include <linux/bitfield.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/gpio.h>
15 #include <linux/kernel.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
18 #include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
19 #include <linux/module.h>
20 #include <linux/of_gpio.h>
21 #include <linux/of_device.h>
22 #include <linux/of_address.h>
23 #include <linux/pci.h>
24 #include <linux/platform_device.h>
25 #include <linux/regmap.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/resource.h>
28 #include <linux/signal.h>
29 #include <linux/types.h>
30 #include <linux/interrupt.h>
31 #include <linux/reset.h>
32 #include <linux/pm_domain.h>
33 #include <linux/pm_runtime.h>
35 #include "pcie-designware.h"
37 #define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
38 #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN BIT(10)
39 #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11)
40 #define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE GENMASK(11, 8)
41 #define IMX8MQ_PCIE2_BASE_ADDR 0x33c00000
43 #define to_imx6_pcie(x) dev_get_drvdata((x)->dev)
45 enum imx6_pcie_variants {
53 #define IMX6_PCIE_FLAG_IMX6_PHY BIT(0)
54 #define IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE BIT(1)
55 #define IMX6_PCIE_FLAG_SUPPORTS_SUSPEND BIT(2)
57 struct imx6_pcie_drvdata {
58 enum imx6_pcie_variants variant;
65 bool gpio_active_high;
68 struct clk *pcie_inbound_axi;
71 struct regmap *iomuxc_gpr;
73 struct reset_control *pciephy_reset;
74 struct reset_control *apps_reset;
75 struct reset_control *turnoff_reset;
77 u32 tx_deemph_gen2_3p5db;
78 u32 tx_deemph_gen2_6db;
82 struct regulator *vpcie;
83 void __iomem *phy_base;
85 /* power domain for pcie */
86 struct device *pd_pcie;
87 /* power domain for pcie phy */
88 struct device *pd_pcie_phy;
89 const struct imx6_pcie_drvdata *drvdata;
92 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
93 #define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200
94 #define PHY_PLL_LOCK_WAIT_TIMEOUT (2000 * PHY_PLL_LOCK_WAIT_USLEEP_MAX)
96 /* PCIe Root Complex registers (memory-mapped) */
97 #define PCIE_RC_IMX6_MSI_CAP 0x50
98 #define PCIE_RC_LCR 0x7c
99 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1
100 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2 0x2
101 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK 0xf
103 #define PCIE_RC_LCSR 0x80
105 /* PCIe Port Logic registers (memory-mapped) */
106 #define PL_OFFSET 0x700
108 #define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
109 #define PCIE_PHY_CTRL_DATA(x) FIELD_PREP(GENMASK(15, 0), (x))
110 #define PCIE_PHY_CTRL_CAP_ADR BIT(16)
111 #define PCIE_PHY_CTRL_CAP_DAT BIT(17)
112 #define PCIE_PHY_CTRL_WR BIT(18)
113 #define PCIE_PHY_CTRL_RD BIT(19)
115 #define PCIE_PHY_STAT (PL_OFFSET + 0x110)
116 #define PCIE_PHY_STAT_ACK BIT(16)
118 #define PCIE_LINK_WIDTH_SPEED_CONTROL 0x80C
120 /* PHY registers (not memory-mapped) */
121 #define PCIE_PHY_ATEOVRD 0x10
122 #define PCIE_PHY_ATEOVRD_EN BIT(2)
123 #define PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT 0
124 #define PCIE_PHY_ATEOVRD_REF_CLKDIV_MASK 0x1
126 #define PCIE_PHY_MPLL_OVRD_IN_LO 0x11
127 #define PCIE_PHY_MPLL_MULTIPLIER_SHIFT 2
128 #define PCIE_PHY_MPLL_MULTIPLIER_MASK 0x7f
129 #define PCIE_PHY_MPLL_MULTIPLIER_OVRD BIT(9)
131 #define PCIE_PHY_RX_ASIC_OUT 0x100D
132 #define PCIE_PHY_RX_ASIC_OUT_VALID (1 << 0)
134 /* iMX7 PCIe PHY registers */
135 #define PCIE_PHY_CMN_REG4 0x14
136 /* These are probably the bits that *aren't* DCC_FB_EN */
137 #define PCIE_PHY_CMN_REG4_DCC_FB_EN 0x29
139 #define PCIE_PHY_CMN_REG15 0x54
140 #define PCIE_PHY_CMN_REG15_DLY_4 BIT(2)
141 #define PCIE_PHY_CMN_REG15_PLL_PD BIT(5)
142 #define PCIE_PHY_CMN_REG15_OVRD_PLL_PD BIT(7)
144 #define PCIE_PHY_CMN_REG24 0x90
145 #define PCIE_PHY_CMN_REG24_RX_EQ BIT(6)
146 #define PCIE_PHY_CMN_REG24_RX_EQ_SEL BIT(3)
148 #define PCIE_PHY_CMN_REG26 0x98
149 #define PCIE_PHY_CMN_REG26_ATT_MODE 0xBC
151 #define PHY_RX_OVRD_IN_LO 0x1005
152 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN BIT(5)
153 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN BIT(3)
155 static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, bool exp_val)
157 struct dw_pcie *pci = imx6_pcie->pci;
159 u32 max_iterations = 10;
160 u32 wait_counter = 0;
163 val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT) &
171 } while (wait_counter < max_iterations);
176 static int pcie_phy_wait_ack(struct imx6_pcie *imx6_pcie, int addr)
178 struct dw_pcie *pci = imx6_pcie->pci;
182 val = PCIE_PHY_CTRL_DATA(addr);
183 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
185 val |= PCIE_PHY_CTRL_CAP_ADR;
186 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
188 ret = pcie_phy_poll_ack(imx6_pcie, true);
192 val = PCIE_PHY_CTRL_DATA(addr);
193 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
195 return pcie_phy_poll_ack(imx6_pcie, false);
198 /* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
199 static int pcie_phy_read(struct imx6_pcie *imx6_pcie, int addr, u16 *data)
201 struct dw_pcie *pci = imx6_pcie->pci;
205 ret = pcie_phy_wait_ack(imx6_pcie, addr);
209 /* assert Read signal */
210 phy_ctl = PCIE_PHY_CTRL_RD;
211 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, phy_ctl);
213 ret = pcie_phy_poll_ack(imx6_pcie, true);
217 *data = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT);
219 /* deassert Read signal */
220 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x00);
222 return pcie_phy_poll_ack(imx6_pcie, false);
225 static int pcie_phy_write(struct imx6_pcie *imx6_pcie, int addr, u16 data)
227 struct dw_pcie *pci = imx6_pcie->pci;
233 ret = pcie_phy_wait_ack(imx6_pcie, addr);
237 var = PCIE_PHY_CTRL_DATA(data);
238 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
241 var |= PCIE_PHY_CTRL_CAP_DAT;
242 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
244 ret = pcie_phy_poll_ack(imx6_pcie, true);
248 /* deassert cap data */
249 var = PCIE_PHY_CTRL_DATA(data);
250 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
252 /* wait for ack de-assertion */
253 ret = pcie_phy_poll_ack(imx6_pcie, false);
257 /* assert wr signal */
258 var = PCIE_PHY_CTRL_WR;
259 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
262 ret = pcie_phy_poll_ack(imx6_pcie, true);
266 /* deassert wr signal */
267 var = PCIE_PHY_CTRL_DATA(data);
268 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
270 /* wait for ack de-assertion */
271 ret = pcie_phy_poll_ack(imx6_pcie, false);
275 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x0);
280 static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie)
284 if (!(imx6_pcie->drvdata->flags & IMX6_PCIE_FLAG_IMX6_PHY))
287 pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
288 tmp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN |
289 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
290 pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
292 usleep_range(2000, 3000);
294 pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
295 tmp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN |
296 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
297 pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
301 /* Added for PCI abort handling */
302 static int imx6q_pcie_abort_handler(unsigned long addr,
303 unsigned int fsr, struct pt_regs *regs)
305 unsigned long pc = instruction_pointer(regs);
306 unsigned long instr = *(unsigned long *)pc;
307 int reg = (instr >> 12) & 15;
310 * If the instruction being executed was a read,
311 * make it look like it read all-ones.
313 if ((instr & 0x0c100000) == 0x04100000) {
316 if (instr & 0x00400000)
321 regs->uregs[reg] = val;
326 if ((instr & 0x0e100090) == 0x00100090) {
327 regs->uregs[reg] = -1;
336 static int imx6_pcie_attach_pd(struct device *dev)
338 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
339 struct device_link *link;
341 /* Do nothing when in a single power domain */
345 imx6_pcie->pd_pcie = dev_pm_domain_attach_by_name(dev, "pcie");
346 if (IS_ERR(imx6_pcie->pd_pcie))
347 return PTR_ERR(imx6_pcie->pd_pcie);
348 /* Do nothing when power domain missing */
349 if (!imx6_pcie->pd_pcie)
351 link = device_link_add(dev, imx6_pcie->pd_pcie,
356 dev_err(dev, "Failed to add device_link to pcie pd.\n");
360 imx6_pcie->pd_pcie_phy = dev_pm_domain_attach_by_name(dev, "pcie_phy");
361 if (IS_ERR(imx6_pcie->pd_pcie_phy))
362 return PTR_ERR(imx6_pcie->pd_pcie_phy);
364 link = device_link_add(dev, imx6_pcie->pd_pcie_phy,
369 dev_err(dev, "Failed to add device_link to pcie_phy pd.\n");
376 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
378 struct device *dev = imx6_pcie->pci->dev;
380 switch (imx6_pcie->drvdata->variant) {
383 reset_control_assert(imx6_pcie->pciephy_reset);
384 reset_control_assert(imx6_pcie->apps_reset);
387 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
388 IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
389 IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
390 /* Force PCIe PHY reset */
391 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
392 IMX6SX_GPR5_PCIE_BTNRST_RESET,
393 IMX6SX_GPR5_PCIE_BTNRST_RESET);
396 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
397 IMX6Q_GPR1_PCIE_SW_RST,
398 IMX6Q_GPR1_PCIE_SW_RST);
401 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
402 IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
403 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
404 IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
408 if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
409 int ret = regulator_disable(imx6_pcie->vpcie);
412 dev_err(dev, "failed to disable vpcie regulator: %d\n",
417 static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie)
419 WARN_ON(imx6_pcie->drvdata->variant != IMX8MQ);
420 return imx6_pcie->controller_id == 1 ? IOMUXC_GPR16 : IOMUXC_GPR14;
423 static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
425 struct dw_pcie *pci = imx6_pcie->pci;
426 struct device *dev = pci->dev;
430 switch (imx6_pcie->drvdata->variant) {
432 ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
434 dev_err(dev, "unable to enable pcie_axi clock\n");
438 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
439 IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
441 case IMX6QP: /* FALLTHROUGH */
443 /* power up core phy and enable ref clock */
444 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
445 IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
447 * the async reset input need ref clock to sync internally,
448 * when the ref clock comes after reset, internal synced
449 * reset time is too short, cannot meet the requirement.
450 * add one ~10us delay here.
452 usleep_range(10, 100);
453 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
454 IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
459 ret = clk_prepare_enable(imx6_pcie->pcie_aux);
461 dev_err(dev, "unable to enable pcie_aux clock\n");
465 offset = imx6_pcie_grp_offset(imx6_pcie);
467 * Set the over ride low and enabled
468 * make sure that REF_CLK is turned on.
470 regmap_update_bits(imx6_pcie->iomuxc_gpr, offset,
471 IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE,
473 regmap_update_bits(imx6_pcie->iomuxc_gpr, offset,
474 IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN,
475 IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN);
482 static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
485 struct device *dev = imx6_pcie->pci->dev;
487 if (regmap_read_poll_timeout(imx6_pcie->iomuxc_gpr,
489 val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED,
490 PHY_PLL_LOCK_WAIT_USLEEP_MAX,
491 PHY_PLL_LOCK_WAIT_TIMEOUT))
492 dev_err(dev, "PCIe PLL lock timeout\n");
495 static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
497 struct dw_pcie *pci = imx6_pcie->pci;
498 struct device *dev = pci->dev;
501 if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
502 ret = regulator_enable(imx6_pcie->vpcie);
504 dev_err(dev, "failed to enable vpcie regulator: %d\n",
510 ret = clk_prepare_enable(imx6_pcie->pcie_phy);
512 dev_err(dev, "unable to enable pcie_phy clock\n");
516 ret = clk_prepare_enable(imx6_pcie->pcie_bus);
518 dev_err(dev, "unable to enable pcie_bus clock\n");
522 ret = clk_prepare_enable(imx6_pcie->pcie);
524 dev_err(dev, "unable to enable pcie clock\n");
528 ret = imx6_pcie_enable_ref_clk(imx6_pcie);
530 dev_err(dev, "unable to enable pcie ref clock\n");
534 /* allow the clocks to stabilize */
535 usleep_range(200, 500);
537 /* Some boards don't have PCIe reset GPIO. */
538 if (gpio_is_valid(imx6_pcie->reset_gpio)) {
539 gpio_set_value_cansleep(imx6_pcie->reset_gpio,
540 imx6_pcie->gpio_active_high);
542 gpio_set_value_cansleep(imx6_pcie->reset_gpio,
543 !imx6_pcie->gpio_active_high);
546 switch (imx6_pcie->drvdata->variant) {
548 reset_control_deassert(imx6_pcie->pciephy_reset);
551 reset_control_deassert(imx6_pcie->pciephy_reset);
553 /* Workaround for ERR010728, failure of PCI-e PLL VCO to
554 * oscillate, especially when cold. This turns off "Duty-cycle
555 * Corrector" and other mysterious undocumented things.
557 if (likely(imx6_pcie->phy_base)) {
558 /* De-assert DCC_FB_EN */
559 writel(PCIE_PHY_CMN_REG4_DCC_FB_EN,
560 imx6_pcie->phy_base + PCIE_PHY_CMN_REG4);
561 /* Assert RX_EQS and RX_EQS_SEL */
562 writel(PCIE_PHY_CMN_REG24_RX_EQ_SEL
563 | PCIE_PHY_CMN_REG24_RX_EQ,
564 imx6_pcie->phy_base + PCIE_PHY_CMN_REG24);
565 /* Assert ATT_MODE */
566 writel(PCIE_PHY_CMN_REG26_ATT_MODE,
567 imx6_pcie->phy_base + PCIE_PHY_CMN_REG26);
569 dev_warn(dev, "Unable to apply ERR010728 workaround. DT missing fsl,imx7d-pcie-phy phandle ?\n");
572 imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
575 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
576 IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
579 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
580 IMX6Q_GPR1_PCIE_SW_RST, 0);
582 usleep_range(200, 500);
584 case IMX6Q: /* Nothing to do */
591 clk_disable_unprepare(imx6_pcie->pcie);
593 clk_disable_unprepare(imx6_pcie->pcie_bus);
595 clk_disable_unprepare(imx6_pcie->pcie_phy);
597 if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
598 ret = regulator_disable(imx6_pcie->vpcie);
600 dev_err(dev, "failed to disable vpcie regulator: %d\n",
605 static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie)
607 unsigned int mask, val;
609 if (imx6_pcie->drvdata->variant == IMX8MQ &&
610 imx6_pcie->controller_id == 1) {
611 mask = IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE;
612 val = FIELD_PREP(IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE,
613 PCI_EXP_TYPE_ROOT_PORT);
615 mask = IMX6Q_GPR12_DEVICE_TYPE;
616 val = FIELD_PREP(IMX6Q_GPR12_DEVICE_TYPE,
617 PCI_EXP_TYPE_ROOT_PORT);
620 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, mask, val);
623 static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
625 switch (imx6_pcie->drvdata->variant) {
628 * TODO: Currently this code assumes external
629 * oscillator is being used
631 regmap_update_bits(imx6_pcie->iomuxc_gpr,
632 imx6_pcie_grp_offset(imx6_pcie),
633 IMX8MQ_GPR_PCIE_REF_USE_PAD,
634 IMX8MQ_GPR_PCIE_REF_USE_PAD);
637 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
638 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
641 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
642 IMX6SX_GPR12_PCIE_RX_EQ_MASK,
643 IMX6SX_GPR12_PCIE_RX_EQ_2);
646 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
647 IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
649 /* configure constant input signal to the pcie ctrl and phy */
650 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
651 IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
653 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
654 IMX6Q_GPR8_TX_DEEMPH_GEN1,
655 imx6_pcie->tx_deemph_gen1 << 0);
656 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
657 IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
658 imx6_pcie->tx_deemph_gen2_3p5db << 6);
659 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
660 IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
661 imx6_pcie->tx_deemph_gen2_6db << 12);
662 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
663 IMX6Q_GPR8_TX_SWING_FULL,
664 imx6_pcie->tx_swing_full << 18);
665 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
666 IMX6Q_GPR8_TX_SWING_LOW,
667 imx6_pcie->tx_swing_low << 25);
671 imx6_pcie_configure_type(imx6_pcie);
674 static int imx6_setup_phy_mpll(struct imx6_pcie *imx6_pcie)
676 unsigned long phy_rate = clk_get_rate(imx6_pcie->pcie_phy);
680 if (!(imx6_pcie->drvdata->flags & IMX6_PCIE_FLAG_IMX6_PHY))
686 * The default settings of the MPLL are for a 125MHz input
687 * clock, so no need to reconfigure anything in that case.
699 dev_err(imx6_pcie->pci->dev,
700 "Unsupported PHY reference clock rate %lu\n", phy_rate);
704 pcie_phy_read(imx6_pcie, PCIE_PHY_MPLL_OVRD_IN_LO, &val);
705 val &= ~(PCIE_PHY_MPLL_MULTIPLIER_MASK <<
706 PCIE_PHY_MPLL_MULTIPLIER_SHIFT);
707 val |= mult << PCIE_PHY_MPLL_MULTIPLIER_SHIFT;
708 val |= PCIE_PHY_MPLL_MULTIPLIER_OVRD;
709 pcie_phy_write(imx6_pcie, PCIE_PHY_MPLL_OVRD_IN_LO, val);
711 pcie_phy_read(imx6_pcie, PCIE_PHY_ATEOVRD, &val);
712 val &= ~(PCIE_PHY_ATEOVRD_REF_CLKDIV_MASK <<
713 PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT);
714 val |= div << PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT;
715 val |= PCIE_PHY_ATEOVRD_EN;
716 pcie_phy_write(imx6_pcie, PCIE_PHY_ATEOVRD, val);
721 static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
723 struct dw_pcie *pci = imx6_pcie->pci;
724 struct device *dev = pci->dev;
726 unsigned int retries;
728 for (retries = 0; retries < 200; retries++) {
729 tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
730 /* Test if the speed change finished. */
731 if (!(tmp & PORT_LOGIC_SPEED_CHANGE))
733 usleep_range(100, 1000);
736 dev_err(dev, "Speed change timeout\n");
740 static void imx6_pcie_ltssm_enable(struct device *dev)
742 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
744 switch (imx6_pcie->drvdata->variant) {
748 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
749 IMX6Q_GPR12_PCIE_CTL_2,
750 IMX6Q_GPR12_PCIE_CTL_2);
754 reset_control_deassert(imx6_pcie->apps_reset);
759 static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
761 struct dw_pcie *pci = imx6_pcie->pci;
762 struct device *dev = pci->dev;
767 * Force Gen1 operation when starting the link. In case the link is
768 * started in Gen2 mode, there is a possibility the devices on the
769 * bus will not be detected at all. This happens with PCIe switches.
771 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
772 tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
773 tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
774 dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
777 imx6_pcie_ltssm_enable(dev);
779 ret = dw_pcie_wait_for_link(pci);
783 if (imx6_pcie->link_gen == 2) {
784 /* Allow Gen2 mode after the link is up. */
785 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
786 tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
787 tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
788 dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
791 * Start Directed Speed Change so the best possible
792 * speed both link partners support can be negotiated.
794 tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
795 tmp |= PORT_LOGIC_SPEED_CHANGE;
796 dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
798 if (imx6_pcie->drvdata->flags &
799 IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE) {
801 * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
802 * from i.MX6 family when no link speed transition
803 * occurs and we go Gen1 -> yep, Gen1. The difference
804 * is that, in such case, it will not be cleared by HW
805 * which will cause the following code to report false
809 ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
811 dev_err(dev, "Failed to bring link up!\n");
816 /* Make sure link training is finished as well! */
817 ret = dw_pcie_wait_for_link(pci);
819 dev_err(dev, "Failed to bring link up!\n");
823 dev_info(dev, "Link: Gen2 disabled\n");
826 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
827 dev_info(dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf);
831 dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
832 dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),
833 dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1));
834 imx6_pcie_reset_phy(imx6_pcie);
838 static int imx6_pcie_host_init(struct pcie_port *pp)
840 struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
841 struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci);
843 imx6_pcie_assert_core_reset(imx6_pcie);
844 imx6_pcie_init_phy(imx6_pcie);
845 imx6_pcie_deassert_core_reset(imx6_pcie);
846 imx6_setup_phy_mpll(imx6_pcie);
847 dw_pcie_setup_rc(pp);
848 imx6_pcie_establish_link(imx6_pcie);
850 if (IS_ENABLED(CONFIG_PCI_MSI))
851 dw_pcie_msi_init(pp);
856 static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
857 .host_init = imx6_pcie_host_init,
860 static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
861 struct platform_device *pdev)
863 struct dw_pcie *pci = imx6_pcie->pci;
864 struct pcie_port *pp = &pci->pp;
865 struct device *dev = &pdev->dev;
868 if (IS_ENABLED(CONFIG_PCI_MSI)) {
869 pp->msi_irq = platform_get_irq_byname(pdev, "msi");
870 if (pp->msi_irq <= 0) {
871 dev_err(dev, "failed to get MSI irq\n");
876 pp->ops = &imx6_pcie_host_ops;
878 ret = dw_pcie_host_init(pp);
880 dev_err(dev, "failed to initialize host\n");
887 static const struct dw_pcie_ops dw_pcie_ops = {
888 /* No special ops needed, but pcie-designware still expects this struct */
891 #ifdef CONFIG_PM_SLEEP
892 static void imx6_pcie_ltssm_disable(struct device *dev)
894 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
896 switch (imx6_pcie->drvdata->variant) {
899 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
900 IMX6Q_GPR12_PCIE_CTL_2, 0);
903 reset_control_assert(imx6_pcie->apps_reset);
906 dev_err(dev, "ltssm_disable not supported\n");
910 static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
912 struct device *dev = imx6_pcie->pci->dev;
914 /* Some variants have a turnoff reset in DT */
915 if (imx6_pcie->turnoff_reset) {
916 reset_control_assert(imx6_pcie->turnoff_reset);
917 reset_control_deassert(imx6_pcie->turnoff_reset);
918 goto pm_turnoff_sleep;
921 /* Others poke directly at IOMUXC registers */
922 switch (imx6_pcie->drvdata->variant) {
924 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
925 IMX6SX_GPR12_PCIE_PM_TURN_OFF,
926 IMX6SX_GPR12_PCIE_PM_TURN_OFF);
927 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
928 IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
931 dev_err(dev, "PME_Turn_Off not implemented\n");
936 * Components with an upstream port must respond to
937 * PME_Turn_Off with PME_TO_Ack but we can't check.
939 * The standard recommends a 1-10ms timeout after which to
940 * proceed anyway as if acks were received.
943 usleep_range(1000, 10000);
946 static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
948 clk_disable_unprepare(imx6_pcie->pcie);
949 clk_disable_unprepare(imx6_pcie->pcie_phy);
950 clk_disable_unprepare(imx6_pcie->pcie_bus);
952 switch (imx6_pcie->drvdata->variant) {
954 clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
957 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
958 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
959 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
962 clk_disable_unprepare(imx6_pcie->pcie_aux);
969 static int imx6_pcie_suspend_noirq(struct device *dev)
971 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
973 if (!(imx6_pcie->drvdata->flags & IMX6_PCIE_FLAG_SUPPORTS_SUSPEND))
976 imx6_pcie_pm_turnoff(imx6_pcie);
977 imx6_pcie_clk_disable(imx6_pcie);
978 imx6_pcie_ltssm_disable(dev);
983 static int imx6_pcie_resume_noirq(struct device *dev)
986 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
987 struct pcie_port *pp = &imx6_pcie->pci->pp;
989 if (!(imx6_pcie->drvdata->flags & IMX6_PCIE_FLAG_SUPPORTS_SUSPEND))
992 imx6_pcie_assert_core_reset(imx6_pcie);
993 imx6_pcie_init_phy(imx6_pcie);
994 imx6_pcie_deassert_core_reset(imx6_pcie);
995 dw_pcie_setup_rc(pp);
997 ret = imx6_pcie_establish_link(imx6_pcie);
999 dev_info(dev, "pcie link is down after resume.\n");
1005 static const struct dev_pm_ops imx6_pcie_pm_ops = {
1006 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq,
1007 imx6_pcie_resume_noirq)
1010 static int imx6_pcie_probe(struct platform_device *pdev)
1012 struct device *dev = &pdev->dev;
1013 struct dw_pcie *pci;
1014 struct imx6_pcie *imx6_pcie;
1015 struct device_node *np;
1016 struct resource *dbi_base;
1017 struct device_node *node = dev->of_node;
1021 imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL);
1025 pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
1030 pci->ops = &dw_pcie_ops;
1032 imx6_pcie->pci = pci;
1033 imx6_pcie->drvdata = of_device_get_match_data(dev);
1035 /* Find the PHY if one is defined, only imx7d uses it */
1036 np = of_parse_phandle(node, "fsl,imx7d-pcie-phy", 0);
1038 struct resource res;
1040 ret = of_address_to_resource(np, 0, &res);
1042 dev_err(dev, "Unable to map PCIe PHY\n");
1045 imx6_pcie->phy_base = devm_ioremap_resource(dev, &res);
1046 if (IS_ERR(imx6_pcie->phy_base)) {
1047 dev_err(dev, "Unable to map PCIe PHY\n");
1048 return PTR_ERR(imx6_pcie->phy_base);
1052 dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1053 pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
1054 if (IS_ERR(pci->dbi_base))
1055 return PTR_ERR(pci->dbi_base);
1058 imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0);
1059 imx6_pcie->gpio_active_high = of_property_read_bool(node,
1060 "reset-gpio-active-high");
1061 if (gpio_is_valid(imx6_pcie->reset_gpio)) {
1062 ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio,
1063 imx6_pcie->gpio_active_high ?
1064 GPIOF_OUT_INIT_HIGH :
1068 dev_err(dev, "unable to get reset gpio\n");
1071 } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) {
1072 return imx6_pcie->reset_gpio;
1076 imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
1077 if (IS_ERR(imx6_pcie->pcie_phy)) {
1078 dev_err(dev, "pcie_phy clock source missing or invalid\n");
1079 return PTR_ERR(imx6_pcie->pcie_phy);
1082 imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
1083 if (IS_ERR(imx6_pcie->pcie_bus)) {
1084 dev_err(dev, "pcie_bus clock source missing or invalid\n");
1085 return PTR_ERR(imx6_pcie->pcie_bus);
1088 imx6_pcie->pcie = devm_clk_get(dev, "pcie");
1089 if (IS_ERR(imx6_pcie->pcie)) {
1090 dev_err(dev, "pcie clock source missing or invalid\n");
1091 return PTR_ERR(imx6_pcie->pcie);
1094 switch (imx6_pcie->drvdata->variant) {
1096 imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
1097 "pcie_inbound_axi");
1098 if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
1099 dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
1100 return PTR_ERR(imx6_pcie->pcie_inbound_axi);
1104 imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux");
1105 if (IS_ERR(imx6_pcie->pcie_aux)) {
1106 dev_err(dev, "pcie_aux clock source missing or invalid\n");
1107 return PTR_ERR(imx6_pcie->pcie_aux);
1111 if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
1112 imx6_pcie->controller_id = 1;
1114 imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev,
1116 if (IS_ERR(imx6_pcie->pciephy_reset)) {
1117 dev_err(dev, "Failed to get PCIEPHY reset control\n");
1118 return PTR_ERR(imx6_pcie->pciephy_reset);
1121 imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
1123 if (IS_ERR(imx6_pcie->apps_reset)) {
1124 dev_err(dev, "Failed to get PCIE APPS reset control\n");
1125 return PTR_ERR(imx6_pcie->apps_reset);
1132 /* Grab turnoff reset */
1133 imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
1134 if (IS_ERR(imx6_pcie->turnoff_reset)) {
1135 dev_err(dev, "Failed to get TURNOFF reset control\n");
1136 return PTR_ERR(imx6_pcie->turnoff_reset);
1139 /* Grab GPR config register range */
1140 imx6_pcie->iomuxc_gpr =
1141 syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
1142 if (IS_ERR(imx6_pcie->iomuxc_gpr)) {
1143 dev_err(dev, "unable to find iomuxc registers\n");
1144 return PTR_ERR(imx6_pcie->iomuxc_gpr);
1147 /* Grab PCIe PHY Tx Settings */
1148 if (of_property_read_u32(node, "fsl,tx-deemph-gen1",
1149 &imx6_pcie->tx_deemph_gen1))
1150 imx6_pcie->tx_deemph_gen1 = 0;
1152 if (of_property_read_u32(node, "fsl,tx-deemph-gen2-3p5db",
1153 &imx6_pcie->tx_deemph_gen2_3p5db))
1154 imx6_pcie->tx_deemph_gen2_3p5db = 0;
1156 if (of_property_read_u32(node, "fsl,tx-deemph-gen2-6db",
1157 &imx6_pcie->tx_deemph_gen2_6db))
1158 imx6_pcie->tx_deemph_gen2_6db = 20;
1160 if (of_property_read_u32(node, "fsl,tx-swing-full",
1161 &imx6_pcie->tx_swing_full))
1162 imx6_pcie->tx_swing_full = 127;
1164 if (of_property_read_u32(node, "fsl,tx-swing-low",
1165 &imx6_pcie->tx_swing_low))
1166 imx6_pcie->tx_swing_low = 127;
1168 /* Limit link speed */
1169 ret = of_property_read_u32(node, "fsl,max-link-speed",
1170 &imx6_pcie->link_gen);
1172 imx6_pcie->link_gen = 1;
1174 imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
1175 if (IS_ERR(imx6_pcie->vpcie)) {
1176 if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
1177 return -EPROBE_DEFER;
1178 imx6_pcie->vpcie = NULL;
1181 platform_set_drvdata(pdev, imx6_pcie);
1183 ret = imx6_pcie_attach_pd(dev);
1187 ret = imx6_add_pcie_port(imx6_pcie, pdev);
1191 if (pci_msi_enabled()) {
1192 val = dw_pcie_readw_dbi(pci, PCIE_RC_IMX6_MSI_CAP +
1194 val |= PCI_MSI_FLAGS_ENABLE;
1195 dw_pcie_writew_dbi(pci, PCIE_RC_IMX6_MSI_CAP + PCI_MSI_FLAGS,
1202 static void imx6_pcie_shutdown(struct platform_device *pdev)
1204 struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev);
1206 /* bring down link, so bootloader gets clean state in case of reboot */
1207 imx6_pcie_assert_core_reset(imx6_pcie);
1210 static const struct imx6_pcie_drvdata drvdata[] = {
1213 .flags = IMX6_PCIE_FLAG_IMX6_PHY |
1214 IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE,
1218 .flags = IMX6_PCIE_FLAG_IMX6_PHY |
1219 IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE |
1220 IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
1224 .flags = IMX6_PCIE_FLAG_IMX6_PHY |
1225 IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE,
1229 .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
1236 static const struct of_device_id imx6_pcie_of_match[] = {
1237 { .compatible = "fsl,imx6q-pcie", .data = &drvdata[IMX6Q], },
1238 { .compatible = "fsl,imx6sx-pcie", .data = &drvdata[IMX6SX], },
1239 { .compatible = "fsl,imx6qp-pcie", .data = &drvdata[IMX6QP], },
1240 { .compatible = "fsl,imx7d-pcie", .data = &drvdata[IMX7D], },
1241 { .compatible = "fsl,imx8mq-pcie", .data = &drvdata[IMX8MQ], } ,
1245 static struct platform_driver imx6_pcie_driver = {
1247 .name = "imx6q-pcie",
1248 .of_match_table = imx6_pcie_of_match,
1249 .suppress_bind_attrs = true,
1250 .pm = &imx6_pcie_pm_ops,
1251 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1253 .probe = imx6_pcie_probe,
1254 .shutdown = imx6_pcie_shutdown,
1257 static int __init imx6_pcie_init(void)
1261 * Since probe() can be deferred we need to make sure that
1262 * hook_fault_code is not called after __init memory is freed
1263 * by kernel and since imx6q_pcie_abort_handler() is a no-op,
1264 * we can install the handler here without risking it
1265 * accessing some uninitialized driver state.
1267 hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
1268 "external abort on non-linefetch");
1271 return platform_driver_register(&imx6_pcie_driver);
1273 device_initcall(imx6_pcie_init);