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/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 #include <linux/pm_domain.h>
31 #include <linux/pm_runtime.h>
33 #include "pcie-designware.h"
35 #define to_imx6_pcie(x) dev_get_drvdata((x)->dev)
37 enum imx6_pcie_variants {
47 bool gpio_active_high;
50 struct clk *pcie_inbound_axi;
52 struct regmap *iomuxc_gpr;
53 struct reset_control *pciephy_reset;
54 struct reset_control *apps_reset;
55 struct reset_control *turnoff_reset;
56 enum imx6_pcie_variants variant;
58 u32 tx_deemph_gen2_3p5db;
59 u32 tx_deemph_gen2_6db;
63 struct regulator *vpcie;
65 /* power domain for pcie */
66 struct device *pd_pcie;
67 /* power domain for pcie phy */
68 struct device *pd_pcie_phy;
71 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
72 #define PHY_PLL_LOCK_WAIT_MAX_RETRIES 2000
73 #define PHY_PLL_LOCK_WAIT_USLEEP_MIN 50
74 #define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200
76 /* PCIe Root Complex registers (memory-mapped) */
77 #define PCIE_RC_LCR 0x7c
78 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1
79 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2 0x2
80 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK 0xf
82 #define PCIE_RC_LCSR 0x80
84 /* PCIe Port Logic registers (memory-mapped) */
85 #define PL_OFFSET 0x700
86 #define PCIE_PL_PFLR (PL_OFFSET + 0x08)
87 #define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16)
88 #define PCIE_PL_PFLR_FORCE_LINK (1 << 15)
89 #define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
90 #define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
91 #define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING (1 << 29)
92 #define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP (1 << 4)
94 #define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
95 #define PCIE_PHY_CTRL_DATA_LOC 0
96 #define PCIE_PHY_CTRL_CAP_ADR_LOC 16
97 #define PCIE_PHY_CTRL_CAP_DAT_LOC 17
98 #define PCIE_PHY_CTRL_WR_LOC 18
99 #define PCIE_PHY_CTRL_RD_LOC 19
101 #define PCIE_PHY_STAT (PL_OFFSET + 0x110)
102 #define PCIE_PHY_STAT_ACK_LOC 16
104 #define PCIE_LINK_WIDTH_SPEED_CONTROL 0x80C
105 #define PORT_LOGIC_SPEED_CHANGE (0x1 << 17)
107 /* PHY registers (not memory-mapped) */
108 #define PCIE_PHY_ATEOVRD 0x10
109 #define PCIE_PHY_ATEOVRD_EN (0x1 << 2)
110 #define PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT 0
111 #define PCIE_PHY_ATEOVRD_REF_CLKDIV_MASK 0x1
113 #define PCIE_PHY_MPLL_OVRD_IN_LO 0x11
114 #define PCIE_PHY_MPLL_MULTIPLIER_SHIFT 2
115 #define PCIE_PHY_MPLL_MULTIPLIER_MASK 0x7f
116 #define PCIE_PHY_MPLL_MULTIPLIER_OVRD (0x1 << 9)
118 #define PCIE_PHY_RX_ASIC_OUT 0x100D
119 #define PCIE_PHY_RX_ASIC_OUT_VALID (1 << 0)
121 #define PHY_RX_OVRD_IN_LO 0x1005
122 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5)
123 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3)
125 static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, int exp_val)
127 struct dw_pcie *pci = imx6_pcie->pci;
129 u32 max_iterations = 10;
130 u32 wait_counter = 0;
133 val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT);
134 val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1;
141 } while (wait_counter < max_iterations);
146 static int pcie_phy_wait_ack(struct imx6_pcie *imx6_pcie, int addr)
148 struct dw_pcie *pci = imx6_pcie->pci;
152 val = addr << PCIE_PHY_CTRL_DATA_LOC;
153 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
155 val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC);
156 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
158 ret = pcie_phy_poll_ack(imx6_pcie, 1);
162 val = addr << PCIE_PHY_CTRL_DATA_LOC;
163 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
165 return pcie_phy_poll_ack(imx6_pcie, 0);
168 /* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
169 static int pcie_phy_read(struct imx6_pcie *imx6_pcie, int addr, int *data)
171 struct dw_pcie *pci = imx6_pcie->pci;
175 ret = pcie_phy_wait_ack(imx6_pcie, addr);
179 /* assert Read signal */
180 phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC;
181 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, phy_ctl);
183 ret = pcie_phy_poll_ack(imx6_pcie, 1);
187 val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT);
188 *data = val & 0xffff;
190 /* deassert Read signal */
191 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x00);
193 return pcie_phy_poll_ack(imx6_pcie, 0);
196 static int pcie_phy_write(struct imx6_pcie *imx6_pcie, int addr, int data)
198 struct dw_pcie *pci = imx6_pcie->pci;
204 ret = pcie_phy_wait_ack(imx6_pcie, addr);
208 var = data << PCIE_PHY_CTRL_DATA_LOC;
209 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
212 var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC);
213 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
215 ret = pcie_phy_poll_ack(imx6_pcie, 1);
219 /* deassert cap data */
220 var = data << PCIE_PHY_CTRL_DATA_LOC;
221 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
223 /* wait for ack de-assertion */
224 ret = pcie_phy_poll_ack(imx6_pcie, 0);
228 /* assert wr signal */
229 var = 0x1 << PCIE_PHY_CTRL_WR_LOC;
230 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
233 ret = pcie_phy_poll_ack(imx6_pcie, 1);
237 /* deassert wr signal */
238 var = data << PCIE_PHY_CTRL_DATA_LOC;
239 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
241 /* wait for ack de-assertion */
242 ret = pcie_phy_poll_ack(imx6_pcie, 0);
246 dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x0);
251 static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie)
255 pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
256 tmp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN |
257 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
258 pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
260 usleep_range(2000, 3000);
262 pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
263 tmp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN |
264 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
265 pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
268 /* Added for PCI abort handling */
269 static int imx6q_pcie_abort_handler(unsigned long addr,
270 unsigned int fsr, struct pt_regs *regs)
272 unsigned long pc = instruction_pointer(regs);
273 unsigned long instr = *(unsigned long *)pc;
274 int reg = (instr >> 12) & 15;
277 * If the instruction being executed was a read,
278 * make it look like it read all-ones.
280 if ((instr & 0x0c100000) == 0x04100000) {
283 if (instr & 0x00400000)
288 regs->uregs[reg] = val;
293 if ((instr & 0x0e100090) == 0x00100090) {
294 regs->uregs[reg] = -1;
302 static int imx6_pcie_attach_pd(struct device *dev)
304 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
305 struct device_link *link;
307 /* Do nothing when in a single power domain */
311 imx6_pcie->pd_pcie = dev_pm_domain_attach_by_name(dev, "pcie");
312 if (IS_ERR(imx6_pcie->pd_pcie))
313 return PTR_ERR(imx6_pcie->pd_pcie);
314 link = device_link_add(dev, imx6_pcie->pd_pcie,
319 dev_err(dev, "Failed to add device_link to pcie pd.\n");
323 imx6_pcie->pd_pcie_phy = dev_pm_domain_attach_by_name(dev, "pcie_phy");
324 if (IS_ERR(imx6_pcie->pd_pcie_phy))
325 return PTR_ERR(imx6_pcie->pd_pcie_phy);
327 device_link_add(dev, imx6_pcie->pd_pcie_phy,
332 dev_err(dev, "Failed to add device_link to pcie_phy pd: %ld\n", PTR_ERR(link));
333 return PTR_ERR(link);
339 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
341 struct device *dev = imx6_pcie->pci->dev;
343 switch (imx6_pcie->variant) {
345 reset_control_assert(imx6_pcie->pciephy_reset);
346 reset_control_assert(imx6_pcie->apps_reset);
349 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
350 IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
351 IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
352 /* Force PCIe PHY reset */
353 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
354 IMX6SX_GPR5_PCIE_BTNRST_RESET,
355 IMX6SX_GPR5_PCIE_BTNRST_RESET);
358 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
359 IMX6Q_GPR1_PCIE_SW_RST,
360 IMX6Q_GPR1_PCIE_SW_RST);
363 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
364 IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
365 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
366 IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
370 if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
371 int ret = regulator_disable(imx6_pcie->vpcie);
374 dev_err(dev, "failed to disable vpcie regulator: %d\n",
379 static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
381 struct dw_pcie *pci = imx6_pcie->pci;
382 struct device *dev = pci->dev;
385 switch (imx6_pcie->variant) {
387 ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
389 dev_err(dev, "unable to enable pcie_axi clock\n");
393 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
394 IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
396 case IMX6QP: /* FALLTHROUGH */
398 /* power up core phy and enable ref clock */
399 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
400 IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
402 * the async reset input need ref clock to sync internally,
403 * when the ref clock comes after reset, internal synced
404 * reset time is too short, cannot meet the requirement.
405 * add one ~10us delay here.
408 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
409 IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
418 static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
421 unsigned int retries;
422 struct device *dev = imx6_pcie->pci->dev;
424 for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) {
425 regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val);
427 if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED)
430 usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN,
431 PHY_PLL_LOCK_WAIT_USLEEP_MAX);
434 dev_err(dev, "PCIe PLL lock timeout\n");
437 static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
439 struct dw_pcie *pci = imx6_pcie->pci;
440 struct device *dev = pci->dev;
443 if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
444 ret = regulator_enable(imx6_pcie->vpcie);
446 dev_err(dev, "failed to enable vpcie regulator: %d\n",
452 ret = clk_prepare_enable(imx6_pcie->pcie_phy);
454 dev_err(dev, "unable to enable pcie_phy clock\n");
458 ret = clk_prepare_enable(imx6_pcie->pcie_bus);
460 dev_err(dev, "unable to enable pcie_bus clock\n");
464 ret = clk_prepare_enable(imx6_pcie->pcie);
466 dev_err(dev, "unable to enable pcie clock\n");
470 ret = imx6_pcie_enable_ref_clk(imx6_pcie);
472 dev_err(dev, "unable to enable pcie ref clock\n");
476 /* allow the clocks to stabilize */
477 usleep_range(200, 500);
479 /* Some boards don't have PCIe reset GPIO. */
480 if (gpio_is_valid(imx6_pcie->reset_gpio)) {
481 gpio_set_value_cansleep(imx6_pcie->reset_gpio,
482 imx6_pcie->gpio_active_high);
484 gpio_set_value_cansleep(imx6_pcie->reset_gpio,
485 !imx6_pcie->gpio_active_high);
488 switch (imx6_pcie->variant) {
490 reset_control_deassert(imx6_pcie->pciephy_reset);
491 imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
494 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
495 IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
498 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
499 IMX6Q_GPR1_PCIE_SW_RST, 0);
501 usleep_range(200, 500);
503 case IMX6Q: /* Nothing to do */
510 clk_disable_unprepare(imx6_pcie->pcie);
512 clk_disable_unprepare(imx6_pcie->pcie_bus);
514 clk_disable_unprepare(imx6_pcie->pcie_phy);
516 if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
517 ret = regulator_disable(imx6_pcie->vpcie);
519 dev_err(dev, "failed to disable vpcie regulator: %d\n",
524 static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
526 switch (imx6_pcie->variant) {
528 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
529 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
532 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
533 IMX6SX_GPR12_PCIE_RX_EQ_MASK,
534 IMX6SX_GPR12_PCIE_RX_EQ_2);
537 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
538 IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
540 /* configure constant input signal to the pcie ctrl and phy */
541 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
542 IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
544 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
545 IMX6Q_GPR8_TX_DEEMPH_GEN1,
546 imx6_pcie->tx_deemph_gen1 << 0);
547 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
548 IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
549 imx6_pcie->tx_deemph_gen2_3p5db << 6);
550 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
551 IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
552 imx6_pcie->tx_deemph_gen2_6db << 12);
553 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
554 IMX6Q_GPR8_TX_SWING_FULL,
555 imx6_pcie->tx_swing_full << 18);
556 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
557 IMX6Q_GPR8_TX_SWING_LOW,
558 imx6_pcie->tx_swing_low << 25);
562 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
563 IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
566 static int imx6_setup_phy_mpll(struct imx6_pcie *imx6_pcie)
568 unsigned long phy_rate = clk_get_rate(imx6_pcie->pcie_phy);
575 * The default settings of the MPLL are for a 125MHz input
576 * clock, so no need to reconfigure anything in that case.
588 dev_err(imx6_pcie->pci->dev,
589 "Unsupported PHY reference clock rate %lu\n", phy_rate);
593 pcie_phy_read(imx6_pcie, PCIE_PHY_MPLL_OVRD_IN_LO, &val);
594 val &= ~(PCIE_PHY_MPLL_MULTIPLIER_MASK <<
595 PCIE_PHY_MPLL_MULTIPLIER_SHIFT);
596 val |= mult << PCIE_PHY_MPLL_MULTIPLIER_SHIFT;
597 val |= PCIE_PHY_MPLL_MULTIPLIER_OVRD;
598 pcie_phy_write(imx6_pcie, PCIE_PHY_MPLL_OVRD_IN_LO, val);
600 pcie_phy_read(imx6_pcie, PCIE_PHY_ATEOVRD, &val);
601 val &= ~(PCIE_PHY_ATEOVRD_REF_CLKDIV_MASK <<
602 PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT);
603 val |= div << PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT;
604 val |= PCIE_PHY_ATEOVRD_EN;
605 pcie_phy_write(imx6_pcie, PCIE_PHY_ATEOVRD, val);
610 static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie)
612 struct dw_pcie *pci = imx6_pcie->pci;
613 struct device *dev = pci->dev;
615 /* check if the link is up or not */
616 if (!dw_pcie_wait_for_link(pci))
619 dev_dbg(dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
620 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
621 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
625 static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
627 struct dw_pcie *pci = imx6_pcie->pci;
628 struct device *dev = pci->dev;
630 unsigned int retries;
632 for (retries = 0; retries < 200; retries++) {
633 tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
634 /* Test if the speed change finished. */
635 if (!(tmp & PORT_LOGIC_SPEED_CHANGE))
637 usleep_range(100, 1000);
640 dev_err(dev, "Speed change timeout\n");
644 static void imx6_pcie_ltssm_enable(struct device *dev)
646 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
648 switch (imx6_pcie->variant) {
652 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
653 IMX6Q_GPR12_PCIE_CTL_2,
654 IMX6Q_GPR12_PCIE_CTL_2);
657 reset_control_deassert(imx6_pcie->apps_reset);
662 static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
664 struct dw_pcie *pci = imx6_pcie->pci;
665 struct device *dev = pci->dev;
670 * Force Gen1 operation when starting the link. In case the link is
671 * started in Gen2 mode, there is a possibility the devices on the
672 * bus will not be detected at all. This happens with PCIe switches.
674 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
675 tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
676 tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
677 dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
680 imx6_pcie_ltssm_enable(dev);
682 ret = imx6_pcie_wait_for_link(imx6_pcie);
686 if (imx6_pcie->link_gen == 2) {
687 /* Allow Gen2 mode after the link is up. */
688 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
689 tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
690 tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
691 dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
694 * Start Directed Speed Change so the best possible
695 * speed both link partners support can be negotiated.
697 tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
698 tmp |= PORT_LOGIC_SPEED_CHANGE;
699 dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
701 if (imx6_pcie->variant != IMX7D) {
703 * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
704 * from i.MX6 family when no link speed transition
705 * occurs and we go Gen1 -> yep, Gen1. The difference
706 * is that, in such case, it will not be cleared by HW
707 * which will cause the following code to report false
711 ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
713 dev_err(dev, "Failed to bring link up!\n");
718 /* Make sure link training is finished as well! */
719 ret = imx6_pcie_wait_for_link(imx6_pcie);
721 dev_err(dev, "Failed to bring link up!\n");
725 dev_info(dev, "Link: Gen2 disabled\n");
728 tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
729 dev_info(dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf);
733 dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
734 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
735 dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
736 imx6_pcie_reset_phy(imx6_pcie);
740 static int imx6_pcie_host_init(struct pcie_port *pp)
742 struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
743 struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci);
745 imx6_pcie_assert_core_reset(imx6_pcie);
746 imx6_pcie_init_phy(imx6_pcie);
747 imx6_pcie_deassert_core_reset(imx6_pcie);
748 imx6_setup_phy_mpll(imx6_pcie);
749 dw_pcie_setup_rc(pp);
750 imx6_pcie_establish_link(imx6_pcie);
752 if (IS_ENABLED(CONFIG_PCI_MSI))
753 dw_pcie_msi_init(pp);
758 static int imx6_pcie_link_up(struct dw_pcie *pci)
760 return dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1) &
761 PCIE_PHY_DEBUG_R1_XMLH_LINK_UP;
764 static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
765 .host_init = imx6_pcie_host_init,
768 static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
769 struct platform_device *pdev)
771 struct dw_pcie *pci = imx6_pcie->pci;
772 struct pcie_port *pp = &pci->pp;
773 struct device *dev = &pdev->dev;
776 if (IS_ENABLED(CONFIG_PCI_MSI)) {
777 pp->msi_irq = platform_get_irq_byname(pdev, "msi");
778 if (pp->msi_irq <= 0) {
779 dev_err(dev, "failed to get MSI irq\n");
784 pp->ops = &imx6_pcie_host_ops;
786 ret = dw_pcie_host_init(pp);
788 dev_err(dev, "failed to initialize host\n");
795 static const struct dw_pcie_ops dw_pcie_ops = {
796 .link_up = imx6_pcie_link_up,
799 #ifdef CONFIG_PM_SLEEP
800 static void imx6_pcie_ltssm_disable(struct device *dev)
802 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
804 switch (imx6_pcie->variant) {
807 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
808 IMX6Q_GPR12_PCIE_CTL_2, 0);
811 reset_control_assert(imx6_pcie->apps_reset);
814 dev_err(dev, "ltssm_disable not supported\n");
818 static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
820 struct device *dev = imx6_pcie->pci->dev;
822 /* Some variants have a turnoff reset in DT */
823 if (imx6_pcie->turnoff_reset) {
824 reset_control_assert(imx6_pcie->turnoff_reset);
825 reset_control_deassert(imx6_pcie->turnoff_reset);
826 goto pm_turnoff_sleep;
829 /* Others poke directly at IOMUXC registers */
830 switch (imx6_pcie->variant) {
832 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
833 IMX6SX_GPR12_PCIE_PM_TURN_OFF,
834 IMX6SX_GPR12_PCIE_PM_TURN_OFF);
835 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
836 IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
839 dev_err(dev, "PME_Turn_Off not implemented\n");
844 * Components with an upstream port must respond to
845 * PME_Turn_Off with PME_TO_Ack but we can't check.
847 * The standard recommends a 1-10ms timeout after which to
848 * proceed anyway as if acks were received.
851 usleep_range(1000, 10000);
854 static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
856 clk_disable_unprepare(imx6_pcie->pcie);
857 clk_disable_unprepare(imx6_pcie->pcie_phy);
858 clk_disable_unprepare(imx6_pcie->pcie_bus);
860 switch (imx6_pcie->variant) {
862 clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
865 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
866 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
867 IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
874 static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
876 return (imx6_pcie->variant == IMX7D ||
877 imx6_pcie->variant == IMX6SX);
880 static int imx6_pcie_suspend_noirq(struct device *dev)
882 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
884 if (!imx6_pcie_supports_suspend(imx6_pcie))
887 imx6_pcie_pm_turnoff(imx6_pcie);
888 imx6_pcie_clk_disable(imx6_pcie);
889 imx6_pcie_ltssm_disable(dev);
894 static int imx6_pcie_resume_noirq(struct device *dev)
897 struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
898 struct pcie_port *pp = &imx6_pcie->pci->pp;
900 if (!imx6_pcie_supports_suspend(imx6_pcie))
903 imx6_pcie_assert_core_reset(imx6_pcie);
904 imx6_pcie_init_phy(imx6_pcie);
905 imx6_pcie_deassert_core_reset(imx6_pcie);
906 dw_pcie_setup_rc(pp);
908 ret = imx6_pcie_establish_link(imx6_pcie);
910 dev_info(dev, "pcie link is down after resume.\n");
916 static const struct dev_pm_ops imx6_pcie_pm_ops = {
917 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq,
918 imx6_pcie_resume_noirq)
921 static int imx6_pcie_probe(struct platform_device *pdev)
923 struct device *dev = &pdev->dev;
925 struct imx6_pcie *imx6_pcie;
926 struct resource *dbi_base;
927 struct device_node *node = dev->of_node;
930 imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL);
934 pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
939 pci->ops = &dw_pcie_ops;
941 imx6_pcie->pci = pci;
943 (enum imx6_pcie_variants)of_device_get_match_data(dev);
945 dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
946 pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
947 if (IS_ERR(pci->dbi_base))
948 return PTR_ERR(pci->dbi_base);
951 imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0);
952 imx6_pcie->gpio_active_high = of_property_read_bool(node,
953 "reset-gpio-active-high");
954 if (gpio_is_valid(imx6_pcie->reset_gpio)) {
955 ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio,
956 imx6_pcie->gpio_active_high ?
957 GPIOF_OUT_INIT_HIGH :
961 dev_err(dev, "unable to get reset gpio\n");
964 } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) {
965 return imx6_pcie->reset_gpio;
969 imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
970 if (IS_ERR(imx6_pcie->pcie_phy)) {
971 dev_err(dev, "pcie_phy clock source missing or invalid\n");
972 return PTR_ERR(imx6_pcie->pcie_phy);
975 imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
976 if (IS_ERR(imx6_pcie->pcie_bus)) {
977 dev_err(dev, "pcie_bus clock source missing or invalid\n");
978 return PTR_ERR(imx6_pcie->pcie_bus);
981 imx6_pcie->pcie = devm_clk_get(dev, "pcie");
982 if (IS_ERR(imx6_pcie->pcie)) {
983 dev_err(dev, "pcie clock source missing or invalid\n");
984 return PTR_ERR(imx6_pcie->pcie);
987 switch (imx6_pcie->variant) {
989 imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
991 if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
992 dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
993 return PTR_ERR(imx6_pcie->pcie_inbound_axi);
997 imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev,
999 if (IS_ERR(imx6_pcie->pciephy_reset)) {
1000 dev_err(dev, "Failed to get PCIEPHY reset control\n");
1001 return PTR_ERR(imx6_pcie->pciephy_reset);
1004 imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
1006 if (IS_ERR(imx6_pcie->apps_reset)) {
1007 dev_err(dev, "Failed to get PCIE APPS reset control\n");
1008 return PTR_ERR(imx6_pcie->apps_reset);
1015 /* Grab turnoff reset */
1016 imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
1017 if (IS_ERR(imx6_pcie->turnoff_reset)) {
1018 dev_err(dev, "Failed to get TURNOFF reset control\n");
1019 return PTR_ERR(imx6_pcie->turnoff_reset);
1022 /* Grab GPR config register range */
1023 imx6_pcie->iomuxc_gpr =
1024 syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
1025 if (IS_ERR(imx6_pcie->iomuxc_gpr)) {
1026 dev_err(dev, "unable to find iomuxc registers\n");
1027 return PTR_ERR(imx6_pcie->iomuxc_gpr);
1030 /* Grab PCIe PHY Tx Settings */
1031 if (of_property_read_u32(node, "fsl,tx-deemph-gen1",
1032 &imx6_pcie->tx_deemph_gen1))
1033 imx6_pcie->tx_deemph_gen1 = 0;
1035 if (of_property_read_u32(node, "fsl,tx-deemph-gen2-3p5db",
1036 &imx6_pcie->tx_deemph_gen2_3p5db))
1037 imx6_pcie->tx_deemph_gen2_3p5db = 0;
1039 if (of_property_read_u32(node, "fsl,tx-deemph-gen2-6db",
1040 &imx6_pcie->tx_deemph_gen2_6db))
1041 imx6_pcie->tx_deemph_gen2_6db = 20;
1043 if (of_property_read_u32(node, "fsl,tx-swing-full",
1044 &imx6_pcie->tx_swing_full))
1045 imx6_pcie->tx_swing_full = 127;
1047 if (of_property_read_u32(node, "fsl,tx-swing-low",
1048 &imx6_pcie->tx_swing_low))
1049 imx6_pcie->tx_swing_low = 127;
1051 /* Limit link speed */
1052 ret = of_property_read_u32(node, "fsl,max-link-speed",
1053 &imx6_pcie->link_gen);
1055 imx6_pcie->link_gen = 1;
1057 imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
1058 if (IS_ERR(imx6_pcie->vpcie)) {
1059 if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
1060 return -EPROBE_DEFER;
1061 imx6_pcie->vpcie = NULL;
1064 platform_set_drvdata(pdev, imx6_pcie);
1066 ret = imx6_pcie_attach_pd(dev);
1070 ret = imx6_add_pcie_port(imx6_pcie, pdev);
1077 static void imx6_pcie_shutdown(struct platform_device *pdev)
1079 struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev);
1081 /* bring down link, so bootloader gets clean state in case of reboot */
1082 imx6_pcie_assert_core_reset(imx6_pcie);
1085 static const struct of_device_id imx6_pcie_of_match[] = {
1086 { .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, },
1087 { .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
1088 { .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
1089 { .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, },
1093 static struct platform_driver imx6_pcie_driver = {
1095 .name = "imx6q-pcie",
1096 .of_match_table = imx6_pcie_of_match,
1097 .suppress_bind_attrs = true,
1098 .pm = &imx6_pcie_pm_ops,
1100 .probe = imx6_pcie_probe,
1101 .shutdown = imx6_pcie_shutdown,
1104 static int __init imx6_pcie_init(void)
1107 * Since probe() can be deferred we need to make sure that
1108 * hook_fault_code is not called after __init memory is freed
1109 * by kernel and since imx6q_pcie_abort_handler() is a no-op,
1110 * we can install the handler here without risking it
1111 * accessing some uninitialized driver state.
1113 hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
1114 "external abort on non-linefetch");
1116 return platform_driver_register(&imx6_pcie_driver);
1118 device_initcall(imx6_pcie_init);