drivers/ata/sata_gemini.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Cortina Systems Gemini SATA bridge add-on to Faraday FTIDE010
  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/bitops.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 #include <linux/delay.h>
 #include <linux/reset.h>
 #include <linux/of.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/pinctrl/consumer.h>
 #include "sata_gemini.h"

 #define DRV_NAME "gemini_sata_bridge"

 /**
  * struct sata_gemini - a state container for a Gemini SATA bridge
  * @dev: the containing device
  * @base: remapped I/O memory base
  * @muxmode: the current muxing mode
  * @ide_pins: if the device is using the plain IDE interface pins
  * @sata_bridge: if the device enables the SATA bridge
  * @sata0_reset: SATA0 reset handler
  * @sata1_reset: SATA1 reset handler
  * @sata0_pclk: SATA0 PCLK handler
  * @sata1_pclk: SATA1 PCLK handler
  */
 struct sata_gemini {
 	struct device *dev;
 	void __iomem *base;
 	enum gemini_muxmode muxmode;
 	bool ide_pins;
 	bool sata_bridge;
 	struct reset_control *sata0_reset;
 	struct reset_control *sata1_reset;
 	struct clk *sata0_pclk;
 	struct clk *sata1_pclk;
 };

 /* Miscellaneous Control Register */
 #define GEMINI_GLOBAL_MISC_CTRL		0x30
 /*
  * Values of IDE IOMUX bits in the misc control register
  *
  * Bits 26:24 are "IDE IO Select", which decides what SATA
  * adapters are connected to which of the two IDE/ATA
  * controllers in the Gemini. We can connect the two IDE blocks
  * to one SATA adapter each, both acting as master, or one IDE
  * blocks to two SATA adapters so the IDE block can act in a
  * master/slave configuration.
  *
  * We also bring out different blocks on the actual IDE
  * pins (not SATA pins) if (and only if) these are muxed in.
  *
  * 111-100 - Reserved
  * Mode 0: 000 - ata0 master <-> sata0
  *               ata1 master <-> sata1
  *               ata0 slave interface brought out on IDE pads
  * Mode 1: 001 - ata0 master <-> sata0
  *               ata1 master <-> sata1
  *               ata1 slave interface brought out on IDE pads
  * Mode 2: 010 - ata1 master <-> sata1
  *               ata1 slave  <-> sata0
  *               ata0 master and slave interfaces brought out
  *                    on IDE pads
  * Mode 3: 011 - ata0 master <-> sata0
  *               ata1 slave  <-> sata1
  *               ata1 master and slave interfaces brought out
  *                    on IDE pads
  */
 #define GEMINI_IDE_IOMUX_MASK			(7 << 24)
 #define GEMINI_IDE_IOMUX_MODE0			(0 << 24)
 #define GEMINI_IDE_IOMUX_MODE1			(1 << 24)
 #define GEMINI_IDE_IOMUX_MODE2			(2 << 24)
 #define GEMINI_IDE_IOMUX_MODE3			(3 << 24)
 #define GEMINI_IDE_IOMUX_SHIFT			(24)

 /*
  * Registers directly controlling the PATA<->SATA adapters
  */
 #define GEMINI_SATA_ID				0x00
 #define GEMINI_SATA_PHY_ID			0x04
 #define GEMINI_SATA0_STATUS			0x08
 #define GEMINI_SATA1_STATUS			0x0c
 #define GEMINI_SATA0_CTRL			0x18
 #define GEMINI_SATA1_CTRL			0x1c

 #define GEMINI_SATA_STATUS_BIST_DONE		BIT(5)
 #define GEMINI_SATA_STATUS_BIST_OK		BIT(4)
 #define GEMINI_SATA_STATUS_PHY_READY		BIT(0)

 #define GEMINI_SATA_CTRL_PHY_BIST_EN		BIT(14)
 #define GEMINI_SATA_CTRL_PHY_FORCE_IDLE		BIT(13)
 #define GEMINI_SATA_CTRL_PHY_FORCE_READY	BIT(12)
 #define GEMINI_SATA_CTRL_PHY_AFE_LOOP_EN	BIT(10)
 #define GEMINI_SATA_CTRL_PHY_DIG_LOOP_EN	BIT(9)
 #define GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN	BIT(4)
 #define GEMINI_SATA_CTRL_ATAPI_EN		BIT(3)
 #define GEMINI_SATA_CTRL_BUS_WITH_20		BIT(2)
 #define GEMINI_SATA_CTRL_SLAVE_EN		BIT(1)
 #define GEMINI_SATA_CTRL_EN			BIT(0)

 /*
  * There is only ever one instance of this bridge on a system,
  * so create a singleton so that the FTIDE010 instances can grab
  * a reference to it.
  */
 static struct sata_gemini *sg_singleton;

 struct sata_gemini *gemini_sata_bridge_get(void)
 {
 	if (sg_singleton)
 		return sg_singleton;
 	return ERR_PTR(-EPROBE_DEFER);
 }
 EXPORT_SYMBOL(gemini_sata_bridge_get);

 bool gemini_sata_bridge_enabled(struct sata_gemini *sg, bool is_ata1)
 {
 	if (!sg->sata_bridge)
 		return false;
 	/*
 	 * In muxmode 2 and 3 one of the ATA controllers is
 	 * actually not connected to any SATA bridge.
 	 */
 	if ((sg->muxmode == GEMINI_MUXMODE_2) &&
 	    !is_ata1)
 		return false;
 	if ((sg->muxmode == GEMINI_MUXMODE_3) &&
 	    is_ata1)
 		return false;

 	return true;
 }
 EXPORT_SYMBOL(gemini_sata_bridge_enabled);

 enum gemini_muxmode gemini_sata_get_muxmode(struct sata_gemini *sg)
 {
 	return sg->muxmode;
 }
 EXPORT_SYMBOL(gemini_sata_get_muxmode);

 static int gemini_sata_setup_bridge(struct sata_gemini *sg,
 				    unsigned int bridge)
 {
 	unsigned long timeout = jiffies + (HZ * 1);
 	bool bridge_online;
 	u32 val;

 	if (bridge == 0) {
 		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
 		/* SATA0 slave mode is only used in muxmode 2 */
 		if (sg->muxmode == GEMINI_MUXMODE_2)
 			val |= GEMINI_SATA_CTRL_SLAVE_EN;
 		writel(val, sg->base + GEMINI_SATA0_CTRL);
 	} else {
 		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
 		/* SATA1 slave mode is only used in muxmode 3 */
 		if (sg->muxmode == GEMINI_MUXMODE_3)
 			val |= GEMINI_SATA_CTRL_SLAVE_EN;
 		writel(val, sg->base + GEMINI_SATA1_CTRL);
 	}

 	/* Vendor code waits 10 ms here */
 	msleep(10);

 	/* Wait for PHY to become ready */
 	do {
 		msleep(100);

 		if (bridge == 0)
 			val = readl(sg->base + GEMINI_SATA0_STATUS);
 		else
 			val = readl(sg->base + GEMINI_SATA1_STATUS);
 		if (val & GEMINI_SATA_STATUS_PHY_READY)
 			break;
 	} while (time_before(jiffies, timeout));

 	bridge_online = !!(val & GEMINI_SATA_STATUS_PHY_READY);

 	dev_info(sg->dev, "SATA%d PHY %s\n", bridge,
 		 bridge_online ? "ready" : "not ready");

 	return bridge_online ? 0: -ENODEV;
 }

 int gemini_sata_start_bridge(struct sata_gemini *sg, unsigned int bridge)
 {
 	struct clk *pclk;
 	int ret;

 	if (bridge == 0)
 		pclk = sg->sata0_pclk;
 	else
 		pclk = sg->sata1_pclk;
 	ret = clk_enable(pclk);
 	if (ret)
 		return ret;

 	msleep(10);

 	/* Do not keep clocking a bridge that is not online */
 	ret = gemini_sata_setup_bridge(sg, bridge);
 	if (ret)
 		clk_disable(pclk);

 	return ret;
 }
 EXPORT_SYMBOL(gemini_sata_start_bridge);

 void gemini_sata_stop_bridge(struct sata_gemini *sg, unsigned int bridge)
 {
 	if (bridge == 0)
 		clk_disable(sg->sata0_pclk);
 	else if (bridge == 1)
 		clk_disable(sg->sata1_pclk);
 }
 EXPORT_SYMBOL(gemini_sata_stop_bridge);

 int gemini_sata_reset_bridge(struct sata_gemini *sg,
 			     unsigned int bridge)
 {
 	if (bridge == 0)
 		reset_control_reset(sg->sata0_reset);
 	else
 		reset_control_reset(sg->sata1_reset);
 	msleep(10);
 	return gemini_sata_setup_bridge(sg, bridge);
 }
 EXPORT_SYMBOL(gemini_sata_reset_bridge);

 static int gemini_sata_bridge_init(struct sata_gemini *sg)
 {
 	struct device *dev = sg->dev;
 	u32 sata_id, sata_phy_id;
 	int ret;

 	sg->sata0_pclk = devm_clk_get(dev, "SATA0_PCLK");
 	if (IS_ERR(sg->sata0_pclk)) {
 		dev_err(dev, "no SATA0 PCLK");
 		return -ENODEV;
 	}
 	sg->sata1_pclk = devm_clk_get(dev, "SATA1_PCLK");
 	if (IS_ERR(sg->sata1_pclk)) {
 		dev_err(dev, "no SATA1 PCLK");
 		return -ENODEV;
 	}

 	ret = clk_prepare_enable(sg->sata0_pclk);
 	if (ret) {
 		dev_err(dev, "failed to enable SATA0 PCLK\n");
 		return ret;
 	}
 	ret = clk_prepare_enable(sg->sata1_pclk);
 	if (ret) {
 		dev_err(dev, "failed to enable SATA1 PCLK\n");
 		clk_disable_unprepare(sg->sata0_pclk);
 		return ret;
 	}

 	sg->sata0_reset = devm_reset_control_get_exclusive(dev, "sata0");
 	if (IS_ERR(sg->sata0_reset)) {
 		dev_err(dev, "no SATA0 reset controller\n");
 		clk_disable_unprepare(sg->sata1_pclk);
 		clk_disable_unprepare(sg->sata0_pclk);
 		return PTR_ERR(sg->sata0_reset);
 	}
 	sg->sata1_reset = devm_reset_control_get_exclusive(dev, "sata1");
 	if (IS_ERR(sg->sata1_reset)) {
 		dev_err(dev, "no SATA1 reset controller\n");
 		clk_disable_unprepare(sg->sata1_pclk);
 		clk_disable_unprepare(sg->sata0_pclk);
 		return PTR_ERR(sg->sata1_reset);
 	}

 	sata_id = readl(sg->base + GEMINI_SATA_ID);
 	sata_phy_id = readl(sg->base + GEMINI_SATA_PHY_ID);
 	sg->sata_bridge = true;
 	clk_disable(sg->sata0_pclk);
 	clk_disable(sg->sata1_pclk);

 	dev_info(dev, "SATA ID %08x, PHY ID: %08x\n", sata_id, sata_phy_id);

 	return 0;
 }

 static int gemini_setup_ide_pins(struct device *dev)
 {
 	struct pinctrl *p;
 	struct pinctrl_state *ide_state;
 	int ret;

 	p = devm_pinctrl_get(dev);
 	if (IS_ERR(p))
 		return PTR_ERR(p);

 	ide_state = pinctrl_lookup_state(p, "ide");
 	if (IS_ERR(ide_state))
 		return PTR_ERR(ide_state);

 	ret = pinctrl_select_state(p, ide_state);
 	if (ret) {
 		dev_err(dev, "could not select IDE state\n");
 		return ret;
 	}

 	return 0;
 }

 static int gemini_sata_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct sata_gemini *sg;
 	struct regmap *map;
 	enum gemini_muxmode muxmode;
 	u32 gmode;
 	u32 gmask;
 	int ret;

 	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
 	if (!sg)
 		return -ENOMEM;
 	sg->dev = dev;

 	sg->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(sg->base))
 		return PTR_ERR(sg->base);

 	map = syscon_regmap_lookup_by_phandle(np, "syscon");
 	if (IS_ERR(map)) {
 		dev_err(dev, "no global syscon\n");
 		return PTR_ERR(map);
 	}

 	/* Set up the SATA bridge if need be */
 	if (of_property_read_bool(np, "cortina,gemini-enable-sata-bridge")) {
 		ret = gemini_sata_bridge_init(sg);
 		if (ret)
 			return ret;
 	}

 	if (of_property_read_bool(np, "cortina,gemini-enable-ide-pins"))
 		sg->ide_pins = true;

 	if (!sg->sata_bridge && !sg->ide_pins) {
 		dev_err(dev, "neither SATA bridge or IDE output enabled\n");
 		ret = -EINVAL;
 		goto out_unprep_clk;
 	}

 	ret = of_property_read_u32(np, "cortina,gemini-ata-muxmode", &muxmode);
 	if (ret) {
 		dev_err(dev, "could not parse ATA muxmode\n");
 		goto out_unprep_clk;
 	}
 	if (muxmode > GEMINI_MUXMODE_3) {
 		dev_err(dev, "illegal muxmode %d\n", muxmode);
 		ret = -EINVAL;
 		goto out_unprep_clk;
 	}
 	sg->muxmode = muxmode;
 	gmask = GEMINI_IDE_IOMUX_MASK;
 	gmode = (muxmode << GEMINI_IDE_IOMUX_SHIFT);

 	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, gmask, gmode);
 	if (ret) {
 		dev_err(dev, "unable to set up IDE muxing\n");
 		ret = -ENODEV;
 		goto out_unprep_clk;
 	}

 	/*
 	 * Route out the IDE pins if desired.
 	 * This is done by looking up a special pin control state called
 	 * "ide" that will route out the IDE pins.
 	 */
 	if (sg->ide_pins) {
 		ret = gemini_setup_ide_pins(dev);
 		if (ret)
 			return ret;
 	}

 	dev_info(dev, "set up the Gemini IDE/SATA nexus\n");
 	platform_set_drvdata(pdev, sg);
 	sg_singleton = sg;

 	return 0;

 out_unprep_clk:
 	if (sg->sata_bridge) {
 		clk_unprepare(sg->sata1_pclk);
 		clk_unprepare(sg->sata0_pclk);
 	}
 	return ret;
 }

 static void gemini_sata_remove(struct platform_device *pdev)
 {
 	struct sata_gemini *sg = platform_get_drvdata(pdev);

 	if (sg->sata_bridge) {
 		clk_unprepare(sg->sata1_pclk);
 		clk_unprepare(sg->sata0_pclk);
 	}
 	sg_singleton = NULL;
 }

 static const struct of_device_id gemini_sata_of_match[] = {
 	{ .compatible = "cortina,gemini-sata-bridge", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, gemini_sata_of_match);

 static struct platform_driver gemini_sata_driver = {
 	.driver = {
 		.name = DRV_NAME,
 		.of_match_table = gemini_sata_of_match,
 	},
 	.probe = gemini_sata_probe,
 	.remove = gemini_sata_remove,
 };
 module_platform_driver(gemini_sata_driver);

 MODULE_DESCRIPTION("low level driver for Cortina Systems Gemini SATA bridge");
 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:" DRV_NAME);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Cortina Systems Gemini SATA bridge add-on to Faraday FTIDE010
	* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/bitops.h>
	#include <linux/mfd/syscon.h>
	#include <linux/regmap.h>
	#include <linux/delay.h>
	#include <linux/reset.h>
	#include <linux/of.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/pinctrl/consumer.h>
	#include "sata_gemini.h"

	#define DRV_NAME "gemini_sata_bridge"

	/**
	* struct sata_gemini - a state container for a Gemini SATA bridge
	* @dev: the containing device
	* @base: remapped I/O memory base
	* @muxmode: the current muxing mode
	* @ide_pins: if the device is using the plain IDE interface pins
	* @sata_bridge: if the device enables the SATA bridge
	* @sata0_reset: SATA0 reset handler
	* @sata1_reset: SATA1 reset handler
	* @sata0_pclk: SATA0 PCLK handler
	* @sata1_pclk: SATA1 PCLK handler
	*/
	struct sata_gemini {
	struct device *dev;
	void __iomem *base;
	enum gemini_muxmode muxmode;
	bool ide_pins;
	bool sata_bridge;
	struct reset_control *sata0_reset;
	struct reset_control *sata1_reset;
	struct clk *sata0_pclk;
	struct clk *sata1_pclk;
	};

	/* Miscellaneous Control Register */
	#define GEMINI_GLOBAL_MISC_CTRL 0x30
	/*
	* Values of IDE IOMUX bits in the misc control register
	*
	* Bits 26:24 are "IDE IO Select", which decides what SATA
	* adapters are connected to which of the two IDE/ATA
	* controllers in the Gemini. We can connect the two IDE blocks
	* to one SATA adapter each, both acting as master, or one IDE
	* blocks to two SATA adapters so the IDE block can act in a
	* master/slave configuration.
	*
	* We also bring out different blocks on the actual IDE
	* pins (not SATA pins) if (and only if) these are muxed in.
	*
	* 111-100 - Reserved
	* Mode 0: 000 - ata0 master <-> sata0
	* ata1 master <-> sata1
	* ata0 slave interface brought out on IDE pads
	* Mode 1: 001 - ata0 master <-> sata0
	* ata1 master <-> sata1
	* ata1 slave interface brought out on IDE pads
	* Mode 2: 010 - ata1 master <-> sata1
	* ata1 slave <-> sata0
	* ata0 master and slave interfaces brought out
	* on IDE pads
	* Mode 3: 011 - ata0 master <-> sata0
	* ata1 slave <-> sata1
	* ata1 master and slave interfaces brought out
	* on IDE pads
	*/
	#define GEMINI_IDE_IOMUX_MASK (7 << 24)
	#define GEMINI_IDE_IOMUX_MODE0 (0 << 24)
	#define GEMINI_IDE_IOMUX_MODE1 (1 << 24)
	#define GEMINI_IDE_IOMUX_MODE2 (2 << 24)
	#define GEMINI_IDE_IOMUX_MODE3 (3 << 24)
	#define GEMINI_IDE_IOMUX_SHIFT (24)

	/*
	* Registers directly controlling the PATA<->SATA adapters
	*/
	#define GEMINI_SATA_ID 0x00
	#define GEMINI_SATA_PHY_ID 0x04
	#define GEMINI_SATA0_STATUS 0x08
	#define GEMINI_SATA1_STATUS 0x0c
	#define GEMINI_SATA0_CTRL 0x18
	#define GEMINI_SATA1_CTRL 0x1c

	#define GEMINI_SATA_STATUS_BIST_DONE BIT(5)
	#define GEMINI_SATA_STATUS_BIST_OK BIT(4)
	#define GEMINI_SATA_STATUS_PHY_READY BIT(0)

	#define GEMINI_SATA_CTRL_PHY_BIST_EN BIT(14)
	#define GEMINI_SATA_CTRL_PHY_FORCE_IDLE BIT(13)
	#define GEMINI_SATA_CTRL_PHY_FORCE_READY BIT(12)
	#define GEMINI_SATA_CTRL_PHY_AFE_LOOP_EN BIT(10)
	#define GEMINI_SATA_CTRL_PHY_DIG_LOOP_EN BIT(9)
	#define GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN BIT(4)
	#define GEMINI_SATA_CTRL_ATAPI_EN BIT(3)
	#define GEMINI_SATA_CTRL_BUS_WITH_20 BIT(2)
	#define GEMINI_SATA_CTRL_SLAVE_EN BIT(1)
	#define GEMINI_SATA_CTRL_EN BIT(0)

	/*
	* There is only ever one instance of this bridge on a system,
	* so create a singleton so that the FTIDE010 instances can grab
	* a reference to it.
	*/
	static struct sata_gemini *sg_singleton;

	struct sata_gemini *gemini_sata_bridge_get(void)
	{
	if (sg_singleton)
	return sg_singleton;
	return ERR_PTR(-EPROBE_DEFER);
	}
	EXPORT_SYMBOL(gemini_sata_bridge_get);

	bool gemini_sata_bridge_enabled(struct sata_gemini *sg, bool is_ata1)
	{
	if (!sg->sata_bridge)
	return false;
	/*
	* In muxmode 2 and 3 one of the ATA controllers is
	* actually not connected to any SATA bridge.
	*/
	if ((sg->muxmode == GEMINI_MUXMODE_2) &&
	!is_ata1)
	return false;
	if ((sg->muxmode == GEMINI_MUXMODE_3) &&
	is_ata1)
	return false;

	return true;
	}
	EXPORT_SYMBOL(gemini_sata_bridge_enabled);

	enum gemini_muxmode gemini_sata_get_muxmode(struct sata_gemini *sg)
	{
	return sg->muxmode;
	}
	EXPORT_SYMBOL(gemini_sata_get_muxmode);

	static int gemini_sata_setup_bridge(struct sata_gemini *sg,
	unsigned int bridge)
	{
	unsigned long timeout = jiffies + (HZ * 1);
	bool bridge_online;
	u32 val;

	if (bridge == 0) {
	val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN \| GEMINI_SATA_CTRL_EN;
	/* SATA0 slave mode is only used in muxmode 2 */
	if (sg->muxmode == GEMINI_MUXMODE_2)
	val \|= GEMINI_SATA_CTRL_SLAVE_EN;
	writel(val, sg->base + GEMINI_SATA0_CTRL);
	} else {
	val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN \| GEMINI_SATA_CTRL_EN;
	/* SATA1 slave mode is only used in muxmode 3 */
	if (sg->muxmode == GEMINI_MUXMODE_3)
	val \|= GEMINI_SATA_CTRL_SLAVE_EN;
	writel(val, sg->base + GEMINI_SATA1_CTRL);
	}

	/* Vendor code waits 10 ms here */
	msleep(10);

	/* Wait for PHY to become ready */
	do {
	msleep(100);

	if (bridge == 0)
	val = readl(sg->base + GEMINI_SATA0_STATUS);
	else
	val = readl(sg->base + GEMINI_SATA1_STATUS);
	if (val & GEMINI_SATA_STATUS_PHY_READY)
	break;
	} while (time_before(jiffies, timeout));

	bridge_online = !!(val & GEMINI_SATA_STATUS_PHY_READY);

	dev_info(sg->dev, "SATA%d PHY %s\n", bridge,
	bridge_online ? "ready" : "not ready");

	return bridge_online ? 0: -ENODEV;
	}

	int gemini_sata_start_bridge(struct sata_gemini *sg, unsigned int bridge)
	{
	struct clk *pclk;
	int ret;

	if (bridge == 0)
	pclk = sg->sata0_pclk;
	else
	pclk = sg->sata1_pclk;
	ret = clk_enable(pclk);
	if (ret)
	return ret;

	msleep(10);

	/* Do not keep clocking a bridge that is not online */
	ret = gemini_sata_setup_bridge(sg, bridge);
	if (ret)
	clk_disable(pclk);

	return ret;
	}
	EXPORT_SYMBOL(gemini_sata_start_bridge);

	void gemini_sata_stop_bridge(struct sata_gemini *sg, unsigned int bridge)
	{
	if (bridge == 0)
	clk_disable(sg->sata0_pclk);
	else if (bridge == 1)
	clk_disable(sg->sata1_pclk);
	}
	EXPORT_SYMBOL(gemini_sata_stop_bridge);

	int gemini_sata_reset_bridge(struct sata_gemini *sg,
	unsigned int bridge)
	{
	if (bridge == 0)
	reset_control_reset(sg->sata0_reset);
	else
	reset_control_reset(sg->sata1_reset);
	msleep(10);
	return gemini_sata_setup_bridge(sg, bridge);
	}
	EXPORT_SYMBOL(gemini_sata_reset_bridge);

	static int gemini_sata_bridge_init(struct sata_gemini *sg)
	{
	struct device *dev = sg->dev;
	u32 sata_id, sata_phy_id;
	int ret;

	sg->sata0_pclk = devm_clk_get(dev, "SATA0_PCLK");
	if (IS_ERR(sg->sata0_pclk)) {
	dev_err(dev, "no SATA0 PCLK");
	return -ENODEV;
	}
	sg->sata1_pclk = devm_clk_get(dev, "SATA1_PCLK");
	if (IS_ERR(sg->sata1_pclk)) {
	dev_err(dev, "no SATA1 PCLK");
	return -ENODEV;
	}

	ret = clk_prepare_enable(sg->sata0_pclk);
	if (ret) {
	dev_err(dev, "failed to enable SATA0 PCLK\n");
	return ret;
	}
	ret = clk_prepare_enable(sg->sata1_pclk);
	if (ret) {
	dev_err(dev, "failed to enable SATA1 PCLK\n");
	clk_disable_unprepare(sg->sata0_pclk);
	return ret;
	}

	sg->sata0_reset = devm_reset_control_get_exclusive(dev, "sata0");
	if (IS_ERR(sg->sata0_reset)) {
	dev_err(dev, "no SATA0 reset controller\n");
	clk_disable_unprepare(sg->sata1_pclk);
	clk_disable_unprepare(sg->sata0_pclk);
	return PTR_ERR(sg->sata0_reset);
	}
	sg->sata1_reset = devm_reset_control_get_exclusive(dev, "sata1");
	if (IS_ERR(sg->sata1_reset)) {
	dev_err(dev, "no SATA1 reset controller\n");
	clk_disable_unprepare(sg->sata1_pclk);
	clk_disable_unprepare(sg->sata0_pclk);
	return PTR_ERR(sg->sata1_reset);
	}

	sata_id = readl(sg->base + GEMINI_SATA_ID);
	sata_phy_id = readl(sg->base + GEMINI_SATA_PHY_ID);
	sg->sata_bridge = true;
	clk_disable(sg->sata0_pclk);
	clk_disable(sg->sata1_pclk);

	dev_info(dev, "SATA ID %08x, PHY ID: %08x\n", sata_id, sata_phy_id);

	return 0;
	}

	static int gemini_setup_ide_pins(struct device *dev)
	{
	struct pinctrl *p;
	struct pinctrl_state *ide_state;
	int ret;

	p = devm_pinctrl_get(dev);
	if (IS_ERR(p))
	return PTR_ERR(p);

	ide_state = pinctrl_lookup_state(p, "ide");
	if (IS_ERR(ide_state))
	return PTR_ERR(ide_state);

	ret = pinctrl_select_state(p, ide_state);
	if (ret) {
	dev_err(dev, "could not select IDE state\n");
	return ret;
	}

	return 0;
	}

	static int gemini_sata_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct sata_gemini *sg;
	struct regmap *map;
	enum gemini_muxmode muxmode;
	u32 gmode;
	u32 gmask;
	int ret;

	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
	if (!sg)
	return -ENOMEM;
	sg->dev = dev;

	sg->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(sg->base))
	return PTR_ERR(sg->base);

	map = syscon_regmap_lookup_by_phandle(np, "syscon");
	if (IS_ERR(map)) {
	dev_err(dev, "no global syscon\n");
	return PTR_ERR(map);
	}

	/* Set up the SATA bridge if need be */
	if (of_property_read_bool(np, "cortina,gemini-enable-sata-bridge")) {
	ret = gemini_sata_bridge_init(sg);
	if (ret)
	return ret;
	}

	if (of_property_read_bool(np, "cortina,gemini-enable-ide-pins"))
	sg->ide_pins = true;

	if (!sg->sata_bridge && !sg->ide_pins) {
	dev_err(dev, "neither SATA bridge or IDE output enabled\n");
	ret = -EINVAL;
	goto out_unprep_clk;
	}

	ret = of_property_read_u32(np, "cortina,gemini-ata-muxmode", &muxmode);
	if (ret) {
	dev_err(dev, "could not parse ATA muxmode\n");
	goto out_unprep_clk;
	}
	if (muxmode > GEMINI_MUXMODE_3) {
	dev_err(dev, "illegal muxmode %d\n", muxmode);
	ret = -EINVAL;
	goto out_unprep_clk;
	}
	sg->muxmode = muxmode;
	gmask = GEMINI_IDE_IOMUX_MASK;
	gmode = (muxmode << GEMINI_IDE_IOMUX_SHIFT);

	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, gmask, gmode);
	if (ret) {
	dev_err(dev, "unable to set up IDE muxing\n");
	ret = -ENODEV;
	goto out_unprep_clk;
	}

	/*
	* Route out the IDE pins if desired.
	* This is done by looking up a special pin control state called
	* "ide" that will route out the IDE pins.
	*/
	if (sg->ide_pins) {
	ret = gemini_setup_ide_pins(dev);
	if (ret)
	return ret;
	}

	dev_info(dev, "set up the Gemini IDE/SATA nexus\n");
	platform_set_drvdata(pdev, sg);
	sg_singleton = sg;

	return 0;

	out_unprep_clk:
	if (sg->sata_bridge) {
	clk_unprepare(sg->sata1_pclk);
	clk_unprepare(sg->sata0_pclk);
	}
	return ret;
	}

	static void gemini_sata_remove(struct platform_device *pdev)
	{
	struct sata_gemini *sg = platform_get_drvdata(pdev);

	if (sg->sata_bridge) {
	clk_unprepare(sg->sata1_pclk);
	clk_unprepare(sg->sata0_pclk);
	}
	sg_singleton = NULL;
	}

	static const struct of_device_id gemini_sata_of_match[] = {
	{ .compatible = "cortina,gemini-sata-bridge", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, gemini_sata_of_match);

	static struct platform_driver gemini_sata_driver = {
	.driver = {
	.name = DRV_NAME,
	.of_match_table = gemini_sata_of_match,
	},
	.probe = gemini_sata_probe,
	.remove = gemini_sata_remove,
	};
	module_platform_driver(gemini_sata_driver);

	MODULE_DESCRIPTION("low level driver for Cortina Systems Gemini SATA bridge");
	MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:" DRV_NAME);