PCI: spear: Add PCIe driver for ST Microelectronics SPEAr13xx

SPEAr13XX PCIe DT detail:

================================

SPEAr13XX uses synopsis designware PCIe controller and ST MiPHY as phy

controller.

Required properties:

- compatible : should be "st,spear1340-pcie", "snps,dw-pcie".

- phys		    : phandle to phy node associated with pcie controller

- phy-names	    : must be "pcie-phy"

- All other definitions as per generic PCI bindings

 Optional properties:

- st,pcie-is-gen1 indicates that forced gen1 initialization is needed.

F:	Documentation/devicetree/bindings/pci/host-generic-pci.txt

F:	drivers/pci/host/pci-host-generic.c

PCIE DRIVER FOR ST SPEAR13XX

M:	Mohit Kumar <mohit.kumar@st.com>

L:	linux-pci@vger.kernel.org

S:	Maintained

F:	drivers/pci/host/*spear*

PCMCIA SUBSYSTEM

P:	Linux PCMCIA Team

L:	linux-pcmcia@lists.infradead.org

	  Say Y here if you want to support a simple generic PCI host

	  controller, such as the one emulated by kvmtool.

config PCIE_SPEAR13XX

	tristate "STMicroelectronics SPEAr PCIe controller"

	depends on ARCH_SPEAR13XX

	select PCIEPORTBUS

	select PCIE_DW

	help

	  Say Y here if you want PCIe support on SPEAr13XX SoCs.

endmenu

obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o

obj-$(CONFIG_PCI_RCAR_GEN2_PCIE) += pcie-rcar.o

obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o

obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o

/*

 * PCIe host controller driver for ST Microelectronics SPEAr13xx SoCs

 *

 * SPEAr13xx PCIe Glue Layer Source Code

 *

 * Copyright (C) 2010-2014 ST Microelectronics

 * Pratyush Anand <pratyush.anand@st.com>

 * Mohit Kumar <mohit.kumar@st.com>

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */

#include <linux/clk.h>

#include <linux/delay.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/pci.h>

#include <linux/phy/phy.h>

#include <linux/platform_device.h>

#include <linux/resource.h>

#include "pcie-designware.h"

struct spear13xx_pcie {

	void __iomem		*app_base;

	struct phy		*phy;

	struct clk		*clk;

	struct pcie_port	pp;

	bool			is_gen1;

};

struct pcie_app_reg {

	u32	app_ctrl_0;		/* cr0 */

	u32	app_ctrl_1;		/* cr1 */

	u32	app_status_0;		/* cr2 */

	u32	app_status_1;		/* cr3 */

	u32	msg_status;		/* cr4 */

	u32	msg_payload;		/* cr5 */

	u32	int_sts;		/* cr6 */

	u32	int_clr;		/* cr7 */

	u32	int_mask;		/* cr8 */

	u32	mst_bmisc;		/* cr9 */

	u32	phy_ctrl;		/* cr10 */

	u32	phy_status;		/* cr11 */

	u32	cxpl_debug_info_0;	/* cr12 */

	u32	cxpl_debug_info_1;	/* cr13 */

	u32	ven_msg_ctrl_0;		/* cr14 */

	u32	ven_msg_ctrl_1;		/* cr15 */

	u32	ven_msg_data_0;		/* cr16 */

	u32	ven_msg_data_1;		/* cr17 */

	u32	ven_msi_0;		/* cr18 */

	u32	ven_msi_1;		/* cr19 */

	u32	mst_rmisc;		/* cr20 */

};

/* CR0 ID */

#define RX_LANE_FLIP_EN_ID			0

#define TX_LANE_FLIP_EN_ID			1

#define SYS_AUX_PWR_DET_ID			2

#define APP_LTSSM_ENABLE_ID			3

#define SYS_ATTEN_BUTTON_PRESSED_ID		4

#define SYS_MRL_SENSOR_STATE_ID			5

#define SYS_PWR_FAULT_DET_ID			6

#define SYS_MRL_SENSOR_CHGED_ID			7

#define SYS_PRE_DET_CHGED_ID			8

#define SYS_CMD_CPLED_INT_ID			9

#define APP_INIT_RST_0_ID			11

#define APP_REQ_ENTR_L1_ID			12

#define APP_READY_ENTR_L23_ID			13

#define APP_REQ_EXIT_L1_ID			14

#define DEVICE_TYPE_EP				(0 << 25)

#define DEVICE_TYPE_LEP				(1 << 25)

#define DEVICE_TYPE_RC				(4 << 25)

#define SYS_INT_ID				29

#define MISCTRL_EN_ID				30

#define REG_TRANSLATION_ENABLE			31

/* CR1 ID */

#define APPS_PM_XMT_TURNOFF_ID			2

#define APPS_PM_XMT_PME_ID			5

/* CR3 ID */

#define XMLH_LTSSM_STATE_DETECT_QUIET		0x00

#define XMLH_LTSSM_STATE_DETECT_ACT		0x01

#define XMLH_LTSSM_STATE_POLL_ACTIVE		0x02

#define XMLH_LTSSM_STATE_POLL_COMPLIANCE	0x03

#define XMLH_LTSSM_STATE_POLL_CONFIG		0x04

#define XMLH_LTSSM_STATE_PRE_DETECT_QUIET	0x05

#define XMLH_LTSSM_STATE_DETECT_WAIT		0x06

#define XMLH_LTSSM_STATE_CFG_LINKWD_START	0x07

#define XMLH_LTSSM_STATE_CFG_LINKWD_ACEPT	0x08

#define XMLH_LTSSM_STATE_CFG_LANENUM_WAIT	0x09

#define XMLH_LTSSM_STATE_CFG_LANENUM_ACEPT	0x0A

#define XMLH_LTSSM_STATE_CFG_COMPLETE		0x0B

#define XMLH_LTSSM_STATE_CFG_IDLE		0x0C

#define XMLH_LTSSM_STATE_RCVRY_LOCK		0x0D

#define XMLH_LTSSM_STATE_RCVRY_SPEED		0x0E

#define XMLH_LTSSM_STATE_RCVRY_RCVRCFG		0x0F

#define XMLH_LTSSM_STATE_RCVRY_IDLE		0x10

#define XMLH_LTSSM_STATE_L0			0x11

#define XMLH_LTSSM_STATE_L0S			0x12

#define XMLH_LTSSM_STATE_L123_SEND_EIDLE	0x13

#define XMLH_LTSSM_STATE_L1_IDLE		0x14

#define XMLH_LTSSM_STATE_L2_IDLE		0x15

#define XMLH_LTSSM_STATE_L2_WAKE		0x16

#define XMLH_LTSSM_STATE_DISABLED_ENTRY		0x17

#define XMLH_LTSSM_STATE_DISABLED_IDLE		0x18

#define XMLH_LTSSM_STATE_DISABLED		0x19

#define XMLH_LTSSM_STATE_LPBK_ENTRY		0x1A

#define XMLH_LTSSM_STATE_LPBK_ACTIVE		0x1B

#define XMLH_LTSSM_STATE_LPBK_EXIT		0x1C

#define XMLH_LTSSM_STATE_LPBK_EXIT_TIMEOUT	0x1D

#define XMLH_LTSSM_STATE_HOT_RESET_ENTRY	0x1E

#define XMLH_LTSSM_STATE_HOT_RESET		0x1F

#define XMLH_LTSSM_STATE_MASK			0x3F

#define XMLH_LINK_UP				(1 << 6)

/* CR4 ID */

#define CFG_MSI_EN_ID				18

/* CR6 */

#define INTA_CTRL_INT				(1 << 7)

#define INTB_CTRL_INT				(1 << 8)

#define INTC_CTRL_INT				(1 << 9)

#define INTD_CTRL_INT				(1 << 10)

#define MSI_CTRL_INT				(1 << 26)

/* CR19 ID */

#define VEN_MSI_REQ_ID				11

#define VEN_MSI_FUN_NUM_ID			8

#define VEN_MSI_TC_ID				5

#define VEN_MSI_VECTOR_ID			0

#define VEN_MSI_REQ_EN		((u32)0x1 << VEN_MSI_REQ_ID)

#define VEN_MSI_FUN_NUM_MASK	((u32)0x7 << VEN_MSI_FUN_NUM_ID)

#define VEN_MSI_TC_MASK		((u32)0x7 << VEN_MSI_TC_ID)

#define VEN_MSI_VECTOR_MASK	((u32)0x1F << VEN_MSI_VECTOR_ID)

#define EXP_CAP_ID_OFFSET			0x70

#define to_spear13xx_pcie(x)	container_of(x, struct spear13xx_pcie, pp)

static int spear13xx_pcie_establish_link(struct pcie_port *pp)

{

	u32 val;

	int count = 0;

	struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pp);

	struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;

	u32 exp_cap_off = EXP_CAP_ID_OFFSET;

	if (dw_pcie_link_up(pp)) {

		dev_err(pp->dev, "link already up\n");

		return 0;

	}

	dw_pcie_setup_rc(pp);

	/*

	 * this controller support only 128 bytes read size, however its

	 * default value in capability register is 512 bytes. So force

	 * it to 128 here.

	 */

	dw_pcie_cfg_read(pp->dbi_base, exp_cap_off + PCI_EXP_DEVCTL, 4, &val);

	val &= ~PCI_EXP_DEVCTL_READRQ;

	dw_pcie_cfg_write(pp->dbi_base, exp_cap_off + PCI_EXP_DEVCTL, 4, val);

	dw_pcie_cfg_write(pp->dbi_base, PCI_VENDOR_ID, 2, 0x104A);

	dw_pcie_cfg_write(pp->dbi_base, PCI_DEVICE_ID, 2, 0xCD80);

	/*

	 * if is_gen1 is set then handle it, so that some buggy card

	 * also works

	 */

	if (spear13xx_pcie->is_gen1) {

		dw_pcie_cfg_read(pp->dbi_base, exp_cap_off + PCI_EXP_LNKCAP, 4,

				 &val);

		if ((val & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {

			val &= ~((u32)PCI_EXP_LNKCAP_SLS);

			val |= PCI_EXP_LNKCAP_SLS_2_5GB;

			dw_pcie_cfg_write(pp->dbi_base, exp_cap_off +

					  PCI_EXP_LNKCAP, 4, val);

		}

		dw_pcie_cfg_read(pp->dbi_base, exp_cap_off + PCI_EXP_LNKCTL2, 4,

				 &val);

		if ((val & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {

			val &= ~((u32)PCI_EXP_LNKCAP_SLS);

			val |= PCI_EXP_LNKCAP_SLS_2_5GB;

			dw_pcie_cfg_write(pp->dbi_base, exp_cap_off +

					  PCI_EXP_LNKCTL2, 4, val);

		}

	}

	/* enable ltssm */

	writel(DEVICE_TYPE_RC | (1 << MISCTRL_EN_ID)

			| (1 << APP_LTSSM_ENABLE_ID)

			| ((u32)1 << REG_TRANSLATION_ENABLE),

			&app_reg->app_ctrl_0);

	/* check if the link is up or not */

	while (!dw_pcie_link_up(pp)) {

		mdelay(100);

		count++;

		if (count == 10) {

			dev_err(pp->dev, "link Fail\n");

			return -EINVAL;

		}

	}

	dev_info(pp->dev, "link up\n");

	return 0;

}

static irqreturn_t spear13xx_pcie_irq_handler(int irq, void *arg)

{

	struct pcie_port *pp = arg;

	struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pp);

	struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;

	unsigned int status;

	status = readl(&app_reg->int_sts);

	if (status & MSI_CTRL_INT) {

		if (!IS_ENABLED(CONFIG_PCI_MSI))

			BUG();

		dw_handle_msi_irq(pp);

	}

	writel(status, &app_reg->int_clr);

	return IRQ_HANDLED;

}

static void spear13xx_pcie_enable_interrupts(struct pcie_port *pp)

{

	struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pp);

	struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;

	/* Enable MSI interrupt */

	if (IS_ENABLED(CONFIG_PCI_MSI)) {

		dw_pcie_msi_init(pp);

		writel(readl(&app_reg->int_mask) |

				MSI_CTRL_INT, &app_reg->int_mask);

	}

}

static int spear13xx_pcie_link_up(struct pcie_port *pp)

{

	struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pp);

	struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;

	if (readl(&app_reg->app_status_1) & XMLH_LINK_UP)

		return 1;

	return 0;

}

static void spear13xx_pcie_host_init(struct pcie_port *pp)

{

	spear13xx_pcie_establish_link(pp);

	spear13xx_pcie_enable_interrupts(pp);

}

static struct pcie_host_ops spear13xx_pcie_host_ops = {

	.link_up = spear13xx_pcie_link_up,

	.host_init = spear13xx_pcie_host_init,

};

static int add_pcie_port(struct pcie_port *pp, struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	int ret;

	pp->irq = platform_get_irq(pdev, 0);

	if (!pp->irq) {

		dev_err(dev, "failed to get irq\n");

		return -ENODEV;

	}

	ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler,

			       IRQF_SHARED, "spear1340-pcie", pp);

	if (ret) {

		dev_err(dev, "failed to request irq %d\n", pp->irq);

		return ret;

	}

	pp->root_bus_nr = -1;

	pp->ops = &spear13xx_pcie_host_ops;

	ret = dw_pcie_host_init(pp);

	if (ret) {

		dev_err(dev, "failed to initialize host\n");

		return ret;

	}

	return 0;

}

static int __init spear13xx_pcie_probe(struct platform_device *pdev)

{

	struct spear13xx_pcie *spear13xx_pcie;

	struct pcie_port *pp;

	struct device *dev = &pdev->dev;

	struct device_node *np = pdev->dev.of_node;

	struct resource *dbi_base;

	int ret;

	spear13xx_pcie = devm_kzalloc(dev, sizeof(*spear13xx_pcie), GFP_KERNEL);

	if (!spear13xx_pcie) {

		dev_err(dev, "no memory for SPEAr13xx pcie\n");

		return -ENOMEM;

	}

	spear13xx_pcie->phy = devm_phy_get(dev, "pcie-phy");

	if (IS_ERR(spear13xx_pcie->phy)) {

		ret = PTR_ERR(spear13xx_pcie->phy);

		if (ret == -EPROBE_DEFER)

			dev_info(dev, "probe deferred\n");

		else

			dev_err(dev, "couldn't get pcie-phy\n");

		return ret;

	}

	phy_init(spear13xx_pcie->phy);

	spear13xx_pcie->clk = devm_clk_get(dev, NULL);

	if (IS_ERR(spear13xx_pcie->clk)) {

		dev_err(dev, "couldn't get clk for pcie\n");

		return PTR_ERR(spear13xx_pcie->clk);

	}

	ret = clk_prepare_enable(spear13xx_pcie->clk);

	if (ret) {

		dev_err(dev, "couldn't enable clk for pcie\n");

		return ret;

	}

	pp = &spear13xx_pcie->pp;

	pp->dev = dev;

	dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	pp->dbi_base = devm_ioremap_resource(dev, dbi_base);

	if (IS_ERR(pp->dbi_base)) {

		dev_err(dev, "couldn't remap dbi base %p\n", dbi_base);

		ret = PTR_ERR(pp->dbi_base);

		goto fail_clk;

	}

	spear13xx_pcie->app_base = pp->dbi_base + 0x2000;

	if (of_property_read_bool(np, "st,pcie-is-gen1"))

		spear13xx_pcie->is_gen1 = true;

	ret = add_pcie_port(pp, pdev);

	if (ret < 0)

		goto fail_clk;

	platform_set_drvdata(pdev, spear13xx_pcie);

	return 0;

fail_clk:

	clk_disable_unprepare(spear13xx_pcie->clk);

	return ret;

}

static int __exit spear13xx_pcie_remove(struct platform_device *pdev)

{

	struct spear13xx_pcie *spear13xx_pcie = platform_get_drvdata(pdev);

	clk_disable_unprepare(spear13xx_pcie->clk);

	phy_exit(spear13xx_pcie->phy);

	return 0;

}

static const struct of_device_id spear13xx_pcie_of_match[] = {

	{ .compatible = "st,spear1340-pcie", },

	{},

};

MODULE_DEVICE_TABLE(of, spear13xx_pcie_of_match);

static struct platform_driver spear13xx_pcie_driver = {

	.probe		= spear13xx_pcie_probe,

	.remove		= spear13xx_pcie_remove,

	.driver = {

		.name	= "spear-pcie",

		.owner	= THIS_MODULE,

		.of_match_table = of_match_ptr(spear13xx_pcie_of_match),

	},

};

/* SPEAr13xx PCIe driver does not allow module unload */

static int __init pcie_init(void)

{

	return platform_driver_register(&spear13xx_pcie_driver);

}

module_init(pcie_init);

MODULE_DESCRIPTION("ST Microelectronics SPEAr13xx PCIe host controller driver");

MODULE_AUTHOR("Pratyush Anand <pratyush.anand@st.com>");

MODULE_LICENSE("GPL v2");