arch/arm/mach-msm/pcie.c

/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

/*
 * MSM PCIe controller driver.
 */

#define pr_fmt(fmt) "%s: " fmt, __func__

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/types.h>
#include <asm/mach/pci.h>
#include <mach/gpiomux.h>
#include <mach/hardware.h>
#include <mach/msm_iomap.h>

#include "pcie.h"

/* Root Complex Port vendor/device IDs */
#define PCIE_VENDOR_ID_RCP             0x17cb
#define PCIE_DEVICE_ID_RCP             0x0101

#define PCIE20_PARF_PCS_DEEMPH         0x34
#define PCIE20_PARF_PCS_SWING          0x38
#define PCIE20_PARF_PHY_CTRL           0x40
#define PCIE20_PARF_PHY_REFCLK         0x4C
#define PCIE20_PARF_CONFIG_BITS        0x50

#define PCIE20_ELBI_SYS_CTRL           0x04

#define PCIE20_CAP                     0x70
#define PCIE20_CAP_LINKCTRLSTATUS      (PCIE20_CAP + 0x10)

#define PCIE20_COMMAND_STATUS          0x04
#define PCIE20_BUSNUMBERS              0x18
#define PCIE20_MEMORY_BASE_LIMIT       0x20

#define PCIE20_PLR_IATU_VIEWPORT       0x900
#define PCIE20_PLR_IATU_CTRL1          0x904
#define PCIE20_PLR_IATU_CTRL2          0x908
#define PCIE20_PLR_IATU_LBAR           0x90C
#define PCIE20_PLR_IATU_UBAR           0x910
#define PCIE20_PLR_IATU_LAR            0x914
#define PCIE20_PLR_IATU_LTAR           0x918
#define PCIE20_PLR_IATU_UTAR           0x91c

#define PCIE_RESET                     (MSM_CLK_CTL_BASE + 0x22dc)
#define PCIE_SFAB_AXI_S5_FCLK_CTL      (MSM_CLK_CTL_BASE + 0x2154)

#define MSM_PCIE_DEV_BAR_ADDR          PCIBIOS_MIN_MEM
#define MSM_PCIE_DEV_CFG_ADDR          0x01000000

#define RD 0
#define WR 1

/* debug mask sys interface */
static int msm_pcie_debug_mask;
module_param_named(debug_mask, msm_pcie_debug_mask,
			    int, S_IRUGO | S_IWUSR | S_IWGRP);

/* resources from device file */
enum msm_pcie_res {
	MSM_PCIE_RES_PARF,
	MSM_PCIE_RES_ELBI,
	MSM_PCIE_RES_PCIE20,
	MSM_PCIE_RES_AXI_BAR,
	MSM_PCIE_RES_AXI_CONF,
	MSM_PCIE_MAX_RES
};

/* msm pcie device data */
static struct msm_pcie_dev_t msm_pcie_dev;

/* regulators */
static struct msm_pcie_vreg_info_t msm_pcie_vreg_info[MSM_PCIE_MAX_VREG] = {
	{NULL, "vp_pcie",      1050000, 1050000, 40900},
	{NULL, "vptx_pcie",    1050000, 1050000, 18200},
	{NULL, "vdd_pcie_vph",       0,       0,     0},
	{NULL, "pcie_ext_3p3v",      0,       0,     0}
};

/* clocks */
static struct msm_pcie_clk_info_t msm_pcie_clk_info[MSM_PCIE_MAX_CLK] = {
	{NULL, "bus_clk"},
	{NULL, "iface_clk"},
	{NULL, "ref_clk"}
};

/* resources */
static struct msm_pcie_res_info_t msm_pcie_res_info[MSM_PCIE_MAX_RES] = {
	{"parf",     0, 0, 0},
	{"elbi",     0, 0, 0},
	{"pcie20",   0, 0, 0},
	{"axi_bar",  0, 0, 0},
	{"axi_conf", 0, 0, 0},
};

int msm_pcie_get_debug_mask(void)
{
	return msm_pcie_debug_mask;
}

static void msm_pcie_write_mask(void __iomem *addr,
				uint32_t clear_mask, uint32_t set_mask)
{
	uint32_t val;

	val = (readl_relaxed(addr) & ~clear_mask) | set_mask;
	writel_relaxed(val, addr);
	wmb();  /* ensure data is written to hardware register */
}

static int msm_pcie_is_link_up(void)
{
	return readl_relaxed(msm_pcie_dev.pcie20 + PCIE20_CAP_LINKCTRLSTATUS) &
				BIT(29);
}

static inline int msm_pcie_oper_conf(struct pci_bus *bus, u32 devfn, int oper,
				     int where, int size, u32 *val)
{
	uint32_t word_offset, byte_offset, mask;
	uint32_t rd_val, wr_val;
	struct msm_pcie_dev_t *dev = &msm_pcie_dev;
	void __iomem *config_base;

	/*
	 * Only buses 0 and 1 are supported. RC port on bus 0 and EP in bus 1.
	 * For downstream bus (1), make sure link is up
	 */
	if ((bus->number > 1) || (devfn != 0)) {
		PCIE_DBG("invalid %s - bus %d devfn %d\n",
			 (oper == RD) ? "rd" : "wr", bus->number, devfn);
		*val = ~0;
		return PCIBIOS_DEVICE_NOT_FOUND;
	} else if ((bus->number != 0) && !msm_pcie_is_link_up()) {
		PCIE_DBG("%s fail, link down - bus %d devfn %d\n",
			 (oper == RD) ? "rd" : "wr", bus->number, devfn);
		*val = ~0;
		return PCIBIOS_DEVICE_NOT_FOUND;
	}

	word_offset = where & ~0x3;
	byte_offset = where & 0x3;
	mask = (~0 >> (8 * (4 - size))) << (8 * byte_offset);

	config_base = (bus->number == 0) ? dev->pcie20 : dev->axi_conf;
	rd_val = readl_relaxed(config_base + word_offset);

	if (oper == RD) {
		*val = ((rd_val & mask) >> (8 * byte_offset));

		PCIE_DBG("%d:0x%02x + 0x%04x[%d] -> 0x%08x; rd 0x%08x\n",
			 bus->number, devfn, where, size, *val, rd_val);
	} else {
		wr_val = (rd_val & ~mask) |
				((*val << (8 * byte_offset)) & mask);
		writel_relaxed(wr_val, config_base + word_offset);
		wmb(); /* ensure config data is written to hardware register */

		PCIE_DBG("%d:0x%02x + 0x%04x[%d] <- 0x%08x;"
			 " rd 0x%08x val 0x%08x\n", bus->number,
			 devfn, where, size, wr_val, rd_val, *val);
	}

	return 0;
}

static int msm_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
			    int size, u32 *val)
{
	return msm_pcie_oper_conf(bus, devfn, RD, where, size, val);
}

static int msm_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
			    int where, int size, u32 val)
{
	return msm_pcie_oper_conf(bus, devfn, WR, where, size, &val);
}

static struct pci_ops msm_pcie_ops = {
	.read = msm_pcie_rd_conf,
	.write = msm_pcie_wr_conf,
};

static int __init msm_pcie_gpio_init(void)
{
	int rc, i;
	struct msm_pcie_gpio_info_t *info;

	for (i = 0; i < MSM_PCIE_MAX_GPIO; i++) {
		info = &msm_pcie_dev.gpio[i];

		rc = gpio_request(info->num, info->name);
		if (rc) {
			pr_err("can't get gpio %s; %d\n", info->name, rc);
			break;
		}

		rc = gpio_direction_output(info->num, 0);
		if (rc) {
			pr_err("can't set gpio direction %s; %d\n",
			       info->name, rc);
			gpio_free(info->num);
			break;
		}
	}

	if (rc)
		while (i--)
			gpio_free(msm_pcie_dev.gpio[i].num);

	return rc;
}

static void msm_pcie_gpio_deinit(void)
{
	int i;

	for (i = 0; i < MSM_PCIE_MAX_GPIO; i++)
		gpio_free(msm_pcie_dev.gpio[i].num);
}

static int __init msm_pcie_vreg_init(struct device *dev)
{
	int i, rc = 0;
	struct regulator *vreg;
	struct msm_pcie_vreg_info_t *info;

	for (i = 0; i < MSM_PCIE_MAX_VREG; i++) {
		info = &msm_pcie_dev.vreg[i];

		vreg = regulator_get(dev, info->name);
		if (!vreg || IS_ERR(vreg)) {
			rc = (PTR_ERR(vreg)) ? PTR_ERR(vreg) : -ENODEV;
			pr_err("can't get %s; %d\n", info->name, rc);
			break;
		}

		if (info->max_v) {
			rc = regulator_set_voltage(vreg,
						   info->min_v, info->max_v);
			if (rc) {
				pr_err("can't set voltage %s; %d\n",
				       info->name, rc);
				regulator_put(vreg);
				break;
			}
		}

		if (info->opt_mode) {
			rc = regulator_set_optimum_mode(vreg, info->opt_mode);
			if (rc < 0) {
				pr_err("can't set mode %s; %d\n",
				       info->name, rc);
				regulator_put(vreg);
				break;
			}
		}

		rc = regulator_enable(vreg);
		if (rc) {
			pr_err("can't enable %s, %d\n", info->name, rc);
			regulator_put(vreg);
			break;
		}
		info->hdl = vreg;
	}

	if (rc)
		while (i--) {
			regulator_disable(msm_pcie_dev.vreg[i].hdl);
			regulator_put(msm_pcie_dev.vreg[i].hdl);
			msm_pcie_dev.vreg[i].hdl = NULL;
		}

	return rc;
}

static void msm_pcie_vreg_deinit(void)
{
	int i;

	for (i = 0; i < MSM_PCIE_MAX_VREG; i++) {
		regulator_disable(msm_pcie_dev.vreg[i].hdl);
		regulator_put(msm_pcie_dev.vreg[i].hdl);
		msm_pcie_dev.vreg[i].hdl = NULL;
	}
}

static int __init msm_pcie_clk_init(struct device *dev)
{
	int i, rc = 0;
	struct clk *clk_hdl;
	struct msm_pcie_clk_info_t *info;

	for (i = 0; i < MSM_PCIE_MAX_CLK; i++) {
		info = &msm_pcie_dev.clk[i];

		clk_hdl = clk_get(dev, info->name);
		if (!clk_hdl || IS_ERR(clk_hdl)) {
			rc = (PTR_ERR(clk_hdl)) ? PTR_ERR(clk_hdl) : -ENODEV;
			pr_err("can't get clk %s; %d\n", info->name, rc);
			break;
		}
		clk_prepare_enable(clk_hdl);
		info->hdl = clk_hdl;
	}

	if (rc)
		while (i--) {
			clk_disable_unprepare(msm_pcie_dev.clk[i].hdl);
			clk_put(msm_pcie_dev.clk[i].hdl);
			msm_pcie_dev.clk[i].hdl = NULL;
		}

	return rc;
}

static void msm_pcie_clk_deinit(void)
{
	int i;

	for (i = 0; i < MSM_PCIE_MAX_CLK; i++) {
		clk_disable_unprepare(msm_pcie_dev.clk[i].hdl);
		clk_put(msm_pcie_dev.clk[i].hdl);
		msm_pcie_dev.clk[i].hdl = NULL;
	}
}

static void __init msm_pcie_config_controller(void)
{
	struct msm_pcie_dev_t *dev = &msm_pcie_dev;
	struct msm_pcie_res_info_t *axi_bar = &dev->res[MSM_PCIE_RES_AXI_BAR];
	struct msm_pcie_res_info_t *axi_conf = &dev->res[MSM_PCIE_RES_AXI_CONF];

	/*
	 * program and enable address translation region 0 (device config
	 * address space); region type config;
	 * axi config address range to device config address range
	 */
	writel_relaxed(0, dev->pcie20 + PCIE20_PLR_IATU_VIEWPORT);
	/* ensure that hardware locks the region before programming it */
	wmb();

	writel_relaxed(4, dev->pcie20 + PCIE20_PLR_IATU_CTRL1);
	writel_relaxed(BIT(31), dev->pcie20 + PCIE20_PLR_IATU_CTRL2);
	writel_relaxed(axi_conf->start, dev->pcie20 + PCIE20_PLR_IATU_LBAR);
	writel_relaxed(0, dev->pcie20 + PCIE20_PLR_IATU_UBAR);
	writel_relaxed(axi_conf->end, dev->pcie20 + PCIE20_PLR_IATU_LAR);
	writel_relaxed(MSM_PCIE_DEV_CFG_ADDR,
		       dev->pcie20 + PCIE20_PLR_IATU_LTAR);
	writel_relaxed(0, dev->pcie20 + PCIE20_PLR_IATU_UTAR);
	/* ensure that hardware registers the configuration */
	wmb();

	/*
	 * program and enable address translation region 2 (device resource
	 * address space); region type memory;
	 * axi device bar address range to device bar address range
	 */
	writel_relaxed(2, dev->pcie20 + PCIE20_PLR_IATU_VIEWPORT);
	/* ensure that hardware locks the region before programming it */
	wmb();

	writel_relaxed(0, dev->pcie20 + PCIE20_PLR_IATU_CTRL1);
	writel_relaxed(BIT(31), dev->pcie20 + PCIE20_PLR_IATU_CTRL2);
	writel_relaxed(axi_bar->start, dev->pcie20 + PCIE20_PLR_IATU_LBAR);
	writel_relaxed(0, dev->pcie20 + PCIE20_PLR_IATU_UBAR);
	writel_relaxed(axi_bar->end, dev->pcie20 + PCIE20_PLR_IATU_LAR);
	writel_relaxed(MSM_PCIE_DEV_BAR_ADDR,
		       dev->pcie20 + PCIE20_PLR_IATU_LTAR);
	writel_relaxed(0, dev->pcie20 + PCIE20_PLR_IATU_UTAR);
	/* ensure that hardware registers the configuration */
	wmb();
}

static int __init msm_pcie_get_resources(struct platform_device *pdev)
{
	int i, rc = 0;
	struct resource *res;
	struct msm_pcie_res_info_t *info;
	struct msm_pcie_dev_t *dev = &msm_pcie_dev;

	for (i = 0; i < MSM_PCIE_MAX_RES; i++) {
		info = &dev->res[i];

		res = platform_get_resource_byname(pdev,
						   IORESOURCE_MEM, info->name);
		if (!res) {
			pr_err("can't get %s resource\n", info->name);
			rc = -ENOMEM;
			break;
		}

		info->base = ioremap(res->start, resource_size(res));
		if (!info->base) {
			pr_err("can't remap %s\n", info->name);
			rc = -ENOMEM;
			break;
		}

		info->start = res->start;
		info->end = res->end;
	}

	if (rc) {
		while (i--) {
			iounmap(dev->res[i].base);
			dev->res[i].base = NULL;
		}
	} else {
		dev->parf = dev->res[MSM_PCIE_RES_PARF].base;
		dev->elbi = dev->res[MSM_PCIE_RES_ELBI].base;
		dev->pcie20 = dev->res[MSM_PCIE_RES_PCIE20].base;
		dev->axi_conf = dev->res[MSM_PCIE_RES_AXI_CONF].base;
	}

	return rc;
}

static void msm_pcie_release_resources(void)
{
	int i;

	for (i = 0; i < MSM_PCIE_MAX_RES; i++) {
		iounmap(msm_pcie_dev.res[i].base);
		msm_pcie_dev.res[i].base = NULL;
	}

	msm_pcie_dev.parf = NULL;
	msm_pcie_dev.elbi = NULL;
	msm_pcie_dev.pcie20 = NULL;
	msm_pcie_dev.axi_conf = NULL;
}

static int __init msm_pcie_setup(int nr, struct pci_sys_data *sys)
{
	int rc;
	struct msm_pcie_dev_t *dev = &msm_pcie_dev;
	uint32_t val;

	PCIE_DBG("bus %d\n", nr);
	if (nr != 0)
		return 0;

	/* assert PCIe reset link to keep EP in reset */
	gpio_set_value_cansleep(dev->gpio[MSM_PCIE_GPIO_RST_N].num,
				dev->gpio[MSM_PCIE_GPIO_RST_N].on);

	/* enable power */
	rc = msm_pcie_vreg_init(&dev->pdev->dev);
	if (rc)
		goto out;

	/* assert PCIe PARF reset while powering the core */
	msm_pcie_write_mask(PCIE_RESET, 0, BIT(2));

	/* enable clocks */
	rc = msm_pcie_clk_init(&dev->pdev->dev);
	if (rc)
		goto clk_fail;

	/* enable pcie power; wait 3ms for clock to stabilize */
	gpio_set_value_cansleep(dev->gpio[MSM_PCIE_GPIO_PWR_EN].num,
				dev->gpio[MSM_PCIE_GPIO_PWR_EN].on);
	usleep(3000);

	/*
	 * de-assert PCIe PARF reset;
	 * wait 1us before accessing PARF registers
	 */
	msm_pcie_write_mask(PCIE_RESET, BIT(2), 0);
	udelay(1);

	/* enable PCIe clocks and resets */
	msm_pcie_write_mask(dev->parf + PCIE20_PARF_PHY_CTRL, BIT(0), 0);

	/* PARF programming */
	writel_relaxed(0x282828, dev->parf + PCIE20_PARF_PCS_DEEMPH);
	writel_relaxed(0x7F7F, dev->parf + PCIE20_PARF_PCS_SWING);
	writel_relaxed((4<<24), dev->parf + PCIE20_PARF_CONFIG_BITS);
	/* ensure that hardware registers the PARF configuration */
	wmb();

	/* enable reference clock */
	msm_pcie_write_mask(dev->parf + PCIE20_PARF_PHY_REFCLK, 0, BIT(16));

	/* enable access to PCIe slave port on system fabric */
	writel_relaxed(BIT(4), PCIE_SFAB_AXI_S5_FCLK_CTL);
	/* ensure that access is enabled before proceeding */
	wmb();

	/* de-assert PICe PHY, Core, POR and AXI clk domain resets */
	msm_pcie_write_mask(PCIE_RESET, BIT(5), 0);
	msm_pcie_write_mask(PCIE_RESET, BIT(4), 0);
	msm_pcie_write_mask(PCIE_RESET, BIT(3), 0);
	msm_pcie_write_mask(PCIE_RESET, BIT(0), 0);

	/* wait 150ms for clock acquisition */
	udelay(150);

	/* de-assert PCIe reset link to bring EP out of reset */
	gpio_set_value_cansleep(dev->gpio[MSM_PCIE_GPIO_RST_N].num,
				!dev->gpio[MSM_PCIE_GPIO_RST_N].on);

	/* enable link training */
	msm_pcie_write_mask(dev->elbi + PCIE20_ELBI_SYS_CTRL, 0, BIT(0));

	/* poll for link to come up for upto 100ms */
	rc = readl_poll_timeout(
			(msm_pcie_dev.pcie20 + PCIE20_CAP_LINKCTRLSTATUS),
			val, (val & BIT(29)), 10000, 100000);
	if (rc) {
		pr_err("link initialization failed\n");
		goto link_fail;
	} else
		pr_info("link initialized\n");

	msm_pcie_config_controller();
	rc = msm_pcie_irq_init(dev);
	if (!rc)
		goto out;

link_fail:
	msm_pcie_clk_deinit();
clk_fail:
	msm_pcie_vreg_deinit();
out:
	return (rc) ? 0 : 1;
}

static struct pci_bus __init *msm_pcie_scan_bus(int nr,
						struct pci_sys_data *sys)
{
	struct pci_bus *bus = NULL;

	PCIE_DBG("bus %d\n", nr);
	if (nr == 0)
		bus = pci_scan_bus(sys->busnr, &msm_pcie_ops, sys);

	return bus;
}

static int __init msm_pcie_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
	PCIE_DBG("slot %d pin %d\n", slot, pin);
	return (pin <= 4) ? (PCIE20_INTA + pin - 1) : 0;
}

static struct hw_pci msm_pci __initdata = {
	.nr_controllers = 1,
	.swizzle = pci_std_swizzle,
	.setup = msm_pcie_setup,
	.scan = msm_pcie_scan_bus,
	.map_irq = msm_pcie_map_irq,
};

static int __init msm_pcie_probe(struct platform_device *pdev)
{
	const struct msm_pcie_platform *pdata;
	int rc;

	PCIE_DBG("\n");

	msm_pcie_dev.pdev = pdev;
	pdata = pdev->dev.platform_data;
	msm_pcie_dev.gpio = pdata->gpio;
	msm_pcie_dev.vreg = msm_pcie_vreg_info;
	msm_pcie_dev.clk = msm_pcie_clk_info;
	msm_pcie_dev.res = msm_pcie_res_info;

	rc = msm_pcie_get_resources(msm_pcie_dev.pdev);
	if (rc)
		return rc;

	rc = msm_pcie_gpio_init();
	if (rc) {
		msm_pcie_release_resources();
		return rc;
	}

	/* kick start ARM PCI configuration framework */
	pci_common_init(&msm_pci);
	return 0;
}

static int __exit msm_pcie_remove(struct platform_device *pdev)
{
	PCIE_DBG("\n");

	msm_pcie_irq_deinit(&msm_pcie_dev);
	msm_pcie_vreg_deinit();
	msm_pcie_clk_deinit();
	msm_pcie_gpio_deinit();
	msm_pcie_release_resources();

	msm_pcie_dev.pdev = NULL;
	msm_pcie_dev.vreg = NULL;
	msm_pcie_dev.clk = NULL;
	msm_pcie_dev.gpio = NULL;
	return 0;
}

static struct platform_driver msm_pcie_driver = {
	.remove = __exit_p(msm_pcie_remove),
	.driver = {
		.name = "msm_pcie",
		.owner = THIS_MODULE,
	},
};

static int __init msm_pcie_init(void)
{
	PCIE_DBG("\n");
	return platform_driver_probe(&msm_pcie_driver, msm_pcie_probe);
}
subsys_initcall(msm_pcie_init);

/* RC do not represent the right class; set it to PCI_CLASS_BRIDGE_PCI */
static void __devinit msm_pcie_fixup_header(struct pci_dev *dev)
{
	PCIE_DBG("hdr_type %d\n", dev->hdr_type);
	if (dev->hdr_type == 1)
		dev->class = (dev->class & 0xff) | (PCI_CLASS_BRIDGE_PCI << 8);
}
DECLARE_PCI_FIXUP_HEADER(PCIE_VENDOR_ID_RCP, PCIE_DEVICE_ID_RCP,
			 msm_pcie_fixup_header);

/*
 * actual physical (BAR) address of the device resources starts from 0x10xxxxxx;
 * the system axi address for the device resources starts from 0x08xxxxxx;
 * correct the device resource structure here; address translation unit handles
 * the required translations
 */
static void __devinit msm_pcie_fixup_final(struct pci_dev *dev)
{
	int i;

	PCIE_DBG("vendor 0x%x 0x%x\n", dev->vendor, dev->device);
	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		if (dev->resource[i].start & 0xFF000000) {
			dev->resource[i].start &= 0x00FFFFFF;
			dev->resource[i].start |= 0x08000000;
			dev->resource[i].end &= 0x00FFFFFF;
			dev->resource[i].end |= 0x08000000;
		}
	}
}
DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, msm_pcie_fixup_final);