drivers/ata/ahci_da850.c - linux - Git at Google

 /*
  * DaVinci DA850 AHCI SATA platform driver
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2, or (at your option)
  * any later version.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/libata.h>
 #include <linux/ahci_platform.h>
 #include "ahci.h"

 #define DRV_NAME		"ahci_da850"
 #define HARDRESET_RETRIES	5

 /* SATA PHY Control Register offset from AHCI base */
 #define SATA_P0PHYCR_REG	0x178

 #define SATA_PHY_MPY(x)		((x) << 0)
 #define SATA_PHY_LOS(x)		((x) << 6)
 #define SATA_PHY_RXCDR(x)	((x) << 10)
 #define SATA_PHY_RXEQ(x)	((x) << 13)
 #define SATA_PHY_TXSWING(x)	((x) << 19)
 #define SATA_PHY_ENPLL(x)	((x) << 31)

 static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
 			    void __iomem *ahci_base, u32 mpy)
 {
 	unsigned int val;

 	/* Enable SATA clock receiver */
 	val = readl(pwrdn_reg);
 	val &= ~BIT(0);
 	writel(val, pwrdn_reg);

 	val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) |
 	      SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1);

 	writel(val, ahci_base + SATA_P0PHYCR_REG);
 }

 static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)
 {
 	u32 pll_output = 1500000000, needed;

 	/*
 	 * We need to determine the value of the multiplier (MPY) bits.
 	 * In order to include the 12.5 multiplier we need to first divide
 	 * the refclk rate by ten.
 	 *
 	 * __div64_32() turned out to be unreliable, sometimes returning
 	 * false results.
 	 */
 	WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");
 	needed = pll_output / (refclk_rate / 10);

 	/*
 	 * What we have now is (multiplier * 10).
 	 *
 	 * Let's determine the actual register value we need to write.
 	 */

 	switch (needed) {
 	case 50:
 		return 0x1;
 	case 60:
 		return 0x2;
 	case 80:
 		return 0x4;
 	case 100:
 		return 0x5;
 	case 120:
 		return 0x6;
 	case 125:
 		return 0x7;
 	case 150:
 		return 0x8;
 	case 200:
 		return 0x9;
 	case 250:
 		return 0xa;
 	default:
 		/*
 		 * We should have divided evenly - if not, return an invalid
 		 * value.
 		 */
 		return 0;
 	}
 }

 static int ahci_da850_softreset(struct ata_link *link,
 				unsigned int *class, unsigned long deadline)
 {
 	int pmp, ret;

 	pmp = sata_srst_pmp(link);

 	/*
 	 * There's an issue with the SATA controller on da850 SoCs: if we
 	 * enable Port Multiplier support, but the drive is connected directly
 	 * to the board, it can't be detected. As a workaround: if PMP is
 	 * enabled, we first call ahci_do_softreset() and pass it the result of
 	 * sata_srst_pmp(). If this call fails, we retry with pmp = 0.
 	 */
 	ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
 	if (pmp && ret == -EBUSY)
 		return ahci_do_softreset(link, class, 0,
 					 deadline, ahci_check_ready);

 	return ret;
 }

 static int ahci_da850_hardreset(struct ata_link *link,
 				unsigned int *class, unsigned long deadline)
 {
 	int ret, retry = HARDRESET_RETRIES;
 	bool online;

 	/*
 	 * In order to correctly service the LCD controller of the da850 SoC,
 	 * we increased the PLL0 frequency to 456MHz from the default 300MHz.
 	 *
 	 * This made the SATA controller unstable and the hardreset operation
 	 * does not always succeed the first time. Before really giving up to
 	 * bring up the link, retry the reset a couple times.
 	 */
 	do {
 		ret = ahci_do_hardreset(link, class, deadline, &online);
 		if (online)
 			return ret;
 	} while (retry--);

 	return ret;
 }

 static struct ata_port_operations ahci_da850_port_ops = {
 	.inherits = &ahci_platform_ops,
 	.softreset = ahci_da850_softreset,
 	/*
 	 * No need to override .pmp_softreset - it's only used for actual
 	 * PMP-enabled ports.
 	 */
 	.hardreset = ahci_da850_hardreset,
 	.pmp_hardreset = ahci_da850_hardreset,
 };

 static const struct ata_port_info ahci_da850_port_info = {
 	.flags		= AHCI_FLAG_COMMON,
 	.pio_mask	= ATA_PIO4,
 	.udma_mask	= ATA_UDMA6,
 	.port_ops	= &ahci_da850_port_ops,
 };

 static struct scsi_host_template ahci_platform_sht = {
 	AHCI_SHT(DRV_NAME),
 };

 static int ahci_da850_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ahci_host_priv *hpriv;
 	void __iomem *pwrdn_reg;
 	struct resource *res;
 	struct clk *clk;
 	u32 mpy;
 	int rc;

 	hpriv = ahci_platform_get_resources(pdev);
 	if (IS_ERR(hpriv))
 		return PTR_ERR(hpriv);

 	/*
 	 * Internally ahci_platform_get_resources() calls clk_get(dev, NULL)
 	 * when trying to obtain the functional clock. This SATA controller
 	 * uses two clocks for which we specify two connection ids. If we don't
 	 * have the functional clock at this point - call clk_get() again with
 	 * con_id = "fck".
 	 */
 	if (!hpriv->clks[0]) {
 		clk = clk_get(dev, "fck");
 		if (IS_ERR(clk))
 			return PTR_ERR(clk);

 		hpriv->clks[0] = clk;
 	}

 	/*
 	 * The second clock used by ahci-da850 is the external REFCLK. If we
 	 * didn't get it from ahci_platform_get_resources(), let's try to
 	 * specify the con_id in clk_get().
 	 */
 	if (!hpriv->clks[1]) {
 		clk = clk_get(dev, "refclk");
 		if (IS_ERR(clk)) {
 			dev_err(dev, "unable to obtain the reference clock");
 			return -ENODEV;
 		}

 		hpriv->clks[1] = clk;
 	}

 	mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1]));
 	if (mpy == 0) {
 		dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy);
 		return -EINVAL;
 	}

 	rc = ahci_platform_enable_resources(hpriv);
 	if (rc)
 		return rc;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 	if (!res)
 		goto disable_resources;

 	pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res));
 	if (!pwrdn_reg)
 		goto disable_resources;

 	da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);

 	rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
 				     &ahci_platform_sht);
 	if (rc)
 		goto disable_resources;

 	return 0;
 disable_resources:
 	ahci_platform_disable_resources(hpriv);
 	return rc;
 }

 static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend,
 			 ahci_platform_resume);

 static const struct of_device_id ahci_da850_of_match[] = {
 	{ .compatible = "ti,da850-ahci", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, ahci_da850_of_match);

 static struct platform_driver ahci_da850_driver = {
 	.probe = ahci_da850_probe,
 	.remove = ata_platform_remove_one,
 	.driver = {
 		.name = DRV_NAME,
 		.of_match_table = ahci_da850_of_match,
 		.pm = &ahci_da850_pm_ops,
 	},
 };
 module_platform_driver(ahci_da850_driver);

 MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver");
 MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>");
 MODULE_LICENSE("GPL");
	/*
	* DaVinci DA850 AHCI SATA platform driver
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2, or (at your option)
	* any later version.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/pm.h>
	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <linux/libata.h>
	#include <linux/ahci_platform.h>
	#include "ahci.h"

	#define DRV_NAME "ahci_da850"
	#define HARDRESET_RETRIES 5

	/* SATA PHY Control Register offset from AHCI base */
	#define SATA_P0PHYCR_REG 0x178

	#define SATA_PHY_MPY(x) ((x) << 0)
	#define SATA_PHY_LOS(x) ((x) << 6)
	#define SATA_PHY_RXCDR(x) ((x) << 10)
	#define SATA_PHY_RXEQ(x) ((x) << 13)
	#define SATA_PHY_TXSWING(x) ((x) << 19)
	#define SATA_PHY_ENPLL(x) ((x) << 31)

	static void da850_sata_init(struct device dev, void __iomem pwrdn_reg,
	void __iomem *ahci_base, u32 mpy)
	{
	unsigned int val;

	/* Enable SATA clock receiver */
	val = readl(pwrdn_reg);
	val &= ~BIT(0);
	writel(val, pwrdn_reg);

	val = SATA_PHY_MPY(mpy) \| SATA_PHY_LOS(1) \| SATA_PHY_RXCDR(4) \|
	SATA_PHY_RXEQ(1) \| SATA_PHY_TXSWING(3) \| SATA_PHY_ENPLL(1);

	writel(val, ahci_base + SATA_P0PHYCR_REG);
	}

	static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)
	{
	u32 pll_output = 1500000000, needed;

	/*
	* We need to determine the value of the multiplier (MPY) bits.
	* In order to include the 12.5 multiplier we need to first divide
	* the refclk rate by ten.
	*
	* __div64_32() turned out to be unreliable, sometimes returning
	* false results.
	*/
	WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");
	needed = pll_output / (refclk_rate / 10);

	/*
	* What we have now is (multiplier * 10).
	*
	* Let's determine the actual register value we need to write.
	*/

	switch (needed) {
	case 50:
	return 0x1;
	case 60:
	return 0x2;
	case 80:
	return 0x4;
	case 100:
	return 0x5;
	case 120:
	return 0x6;
	case 125:
	return 0x7;
	case 150:
	return 0x8;
	case 200:
	return 0x9;
	case 250:
	return 0xa;
	default:
	/*
	* We should have divided evenly - if not, return an invalid
	* value.
	*/
	return 0;
	}
	}

	static int ahci_da850_softreset(struct ata_link *link,
	unsigned int *class, unsigned long deadline)
	{
	int pmp, ret;

	pmp = sata_srst_pmp(link);

	/*
	* There's an issue with the SATA controller on da850 SoCs: if we
	* enable Port Multiplier support, but the drive is connected directly
	* to the board, it can't be detected. As a workaround: if PMP is
	* enabled, we first call ahci_do_softreset() and pass it the result of
	* sata_srst_pmp(). If this call fails, we retry with pmp = 0.
	*/
	ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
	if (pmp && ret == -EBUSY)
	return ahci_do_softreset(link, class, 0,
	deadline, ahci_check_ready);

	return ret;
	}

	static int ahci_da850_hardreset(struct ata_link *link,
	unsigned int *class, unsigned long deadline)
	{
	int ret, retry = HARDRESET_RETRIES;
	bool online;

	/*
	* In order to correctly service the LCD controller of the da850 SoC,
	* we increased the PLL0 frequency to 456MHz from the default 300MHz.
	*
	* This made the SATA controller unstable and the hardreset operation
	* does not always succeed the first time. Before really giving up to
	* bring up the link, retry the reset a couple times.
	*/
	do {
	ret = ahci_do_hardreset(link, class, deadline, &online);
	if (online)
	return ret;
	} while (retry--);

	return ret;
	}

	static struct ata_port_operations ahci_da850_port_ops = {
	.inherits = &ahci_platform_ops,
	.softreset = ahci_da850_softreset,
	/*
	* No need to override .pmp_softreset - it's only used for actual
	* PMP-enabled ports.
	*/
	.hardreset = ahci_da850_hardreset,
	.pmp_hardreset = ahci_da850_hardreset,
	};

	static const struct ata_port_info ahci_da850_port_info = {
	.flags = AHCI_FLAG_COMMON,
	.pio_mask = ATA_PIO4,
	.udma_mask = ATA_UDMA6,
	.port_ops = &ahci_da850_port_ops,
	};

	static struct scsi_host_template ahci_platform_sht = {
	AHCI_SHT(DRV_NAME),
	};

	static int ahci_da850_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct ahci_host_priv *hpriv;
	void __iomem *pwrdn_reg;
	struct resource *res;
	struct clk *clk;
	u32 mpy;
	int rc;

	hpriv = ahci_platform_get_resources(pdev);
	if (IS_ERR(hpriv))
	return PTR_ERR(hpriv);

	/*
	* Internally ahci_platform_get_resources() calls clk_get(dev, NULL)
	* when trying to obtain the functional clock. This SATA controller
	* uses two clocks for which we specify two connection ids. If we don't
	* have the functional clock at this point - call clk_get() again with
	* con_id = "fck".
	*/
	if (!hpriv->clks[0]) {
	clk = clk_get(dev, "fck");
	if (IS_ERR(clk))
	return PTR_ERR(clk);

	hpriv->clks[0] = clk;
	}

	/*
	* The second clock used by ahci-da850 is the external REFCLK. If we
	* didn't get it from ahci_platform_get_resources(), let's try to
	* specify the con_id in clk_get().
	*/
	if (!hpriv->clks[1]) {
	clk = clk_get(dev, "refclk");
	if (IS_ERR(clk)) {
	dev_err(dev, "unable to obtain the reference clock");
	return -ENODEV;
	}

	hpriv->clks[1] = clk;
	}

	mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1]));
	if (mpy == 0) {
	dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy);
	return -EINVAL;
	}

	rc = ahci_platform_enable_resources(hpriv);
	if (rc)
	return rc;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	if (!res)
	goto disable_resources;

	pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res));
	if (!pwrdn_reg)
	goto disable_resources;

	da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);

	rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
	&ahci_platform_sht);
	if (rc)
	goto disable_resources;

	return 0;
	disable_resources:
	ahci_platform_disable_resources(hpriv);
	return rc;
	}

	static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend,
	ahci_platform_resume);

	static const struct of_device_id ahci_da850_of_match[] = {
	{ .compatible = "ti,da850-ahci", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, ahci_da850_of_match);

	static struct platform_driver ahci_da850_driver = {
	.probe = ahci_da850_probe,
	.remove = ata_platform_remove_one,
	.driver = {
	.name = DRV_NAME,
	.of_match_table = ahci_da850_of_match,
	.pm = &ahci_da850_pm_ops,
	},
	};
	module_platform_driver(ahci_da850_driver);

	MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver");
	MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>");
	MODULE_LICENSE("GPL");