Commit 8b789d89 authored by Richard Zhu's avatar Richard Zhu Committed by Tejun Heo
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ahci: imx: setup power saving methods 



In order to save power consumption as much as possible.

* Disable sata phy internal pll reference clock when sysetem enter
  into suspend mode, enable it after resume.

* Setup module parameter used to enable imx ahci test power down
  mode(PDDQ) or not, when there is no device detected on the port

* minor modifications:
  - The format of the copyright is changed, because that the original
    one can't pass fsl internal patch reivew without the character
    '(c)'.
  - Exports ahci_platform_ops and ahci_error_handler().

NOTE:
* The hot-plug can't be supported when PDDQ mode is ever enabled.

* module parameter usage how-to:
  - default: enable PDDQ mode when no device detected.
  - add "ahci-imx.hotplug=1" into kernel command line if your don't
    want to enable PDDQ mode when no device detected on the port.

tj: Slightly updated description and comments.

Signed-off-by: default avatarRichard Zhu <r65037@freescale.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 89951f22

drivers/ata/ahci.h

+2 −0
Original line number Diff line number Diff line
@@ -339,6 +339,7 @@ extern struct device_attribute *ahci_sdev_attrs[]; 
	.sdev_attrs		= ahci_sdev_attrs



extern struct ata_port_operations ahci_ops;

extern struct ata_port_operations ahci_platform_ops;

extern struct ata_port_operations ahci_pmp_retry_srst_ops;



unsigned int ahci_dev_classify(struct ata_port *ap);
@@ -368,6 +369,7 @@ irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance); 
irqreturn_t ahci_thread_fn(int irq, void *dev_instance);

void ahci_print_info(struct ata_host *host, const char *scc_s);

int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis);

void ahci_error_handler(struct ata_port *ap);



static inline void __iomem *__ahci_port_base(struct ata_host *host,

					     unsigned int port_no)

drivers/ata/ahci_imx.c

+99 −2
Original line number Diff line number Diff line 
/*

 * copyright (c) 2013 Freescale Semiconductor, Inc.

 * Freescale IMX AHCI SATA platform driver

 * Copyright 2013 Freescale Semiconductor, Inc.

 *

 * based on the AHCI SATA platform driver by Jeff Garzik and Anton Vorontsov

 *
@@ -25,9 +25,12 @@ 
#include <linux/of_device.h>

#include <linux/mfd/syscon.h>

#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>

#include <linux/libata.h>

#include "ahci.h"



enum {

	PORT_PHY_CTL = 0x178,			/* Port0 PHY Control */

	PORT_PHY_CTL_PDDQ_LOC = 0x100000,	/* PORT_PHY_CTL bits */

	HOST_TIMER1MS = 0xe0,			/* Timer 1-ms */

};
@@ -36,6 +39,56 @@ struct imx_ahci_priv { 
	struct clk *sata_ref_clk;

	struct clk *ahb_clk;

	struct regmap *gpr;

	bool no_device;

	bool first_time;

};



static int ahci_imx_hotplug;

module_param_named(hotplug, ahci_imx_hotplug, int, 0644);

MODULE_PARM_DESC(hotplug, "AHCI IMX hot-plug support (0=Don't support, 1=support)");



static void ahci_imx_error_handler(struct ata_port *ap)

{

	u32 reg_val;

	struct ata_device *dev;

	struct ata_host *host = dev_get_drvdata(ap->dev);

	struct ahci_host_priv *hpriv = host->private_data;

	void __iomem *mmio = hpriv->mmio;

	struct imx_ahci_priv *imxpriv = dev_get_drvdata(ap->dev->parent);



	ahci_error_handler(ap);



	if (!(imxpriv->first_time) || ahci_imx_hotplug)

		return;



	imxpriv->first_time = false;



	ata_for_each_dev(dev, &ap->link, ENABLED)

		return;

	/*

	 * Disable link to save power.  An imx ahci port can't be recovered

	 * without full reset once the pddq mode is enabled making it

	 * impossible to use as part of libata LPM.

	 */

	reg_val = readl(mmio + PORT_PHY_CTL);

	writel(reg_val | PORT_PHY_CTL_PDDQ_LOC, mmio + PORT_PHY_CTL);

	regmap_update_bits(imxpriv->gpr, IOMUXC_GPR13,

			IMX6Q_GPR13_SATA_MPLL_CLK_EN,

			!IMX6Q_GPR13_SATA_MPLL_CLK_EN);

	clk_disable_unprepare(imxpriv->sata_ref_clk);

	imxpriv->no_device = true;

}



static struct ata_port_operations ahci_imx_ops = {

	.inherits	= &ahci_platform_ops,

	.error_handler	= ahci_imx_error_handler,

};



static const struct ata_port_info ahci_imx_port_info = {

	.flags		= AHCI_FLAG_COMMON,

	.pio_mask	= ATA_PIO4,

	.udma_mask	= ATA_UDMA6,

	.port_ops	= &ahci_imx_ops,

};



static int imx6q_sata_init(struct device *dev, void __iomem *mmio)
@@ -117,9 +170,51 @@ static void imx6q_sata_exit(struct device *dev) 
	clk_disable_unprepare(imxpriv->sata_ref_clk);

}



static int imx_ahci_suspend(struct device *dev)

{

	struct imx_ahci_priv *imxpriv =  dev_get_drvdata(dev->parent);



	/*

	 * If no_device is set, The CLKs had been gated off in the

	 * initialization so don't do it again here.

	 */

	if (!imxpriv->no_device) {

		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR13,

				IMX6Q_GPR13_SATA_MPLL_CLK_EN,

				!IMX6Q_GPR13_SATA_MPLL_CLK_EN);

		clk_disable_unprepare(imxpriv->sata_ref_clk);

	}



	return 0;

}



static int imx_ahci_resume(struct device *dev)

{

	struct imx_ahci_priv *imxpriv =  dev_get_drvdata(dev->parent);

	int ret;



	if (!imxpriv->no_device) {

		ret = clk_prepare_enable(imxpriv->sata_ref_clk);

		if (ret < 0) {

			dev_err(dev, "pre-enable sata_ref clock err:%d\n", ret);

			return ret;

		}



		regmap_update_bits(imxpriv->gpr, IOMUXC_GPR13,

				IMX6Q_GPR13_SATA_MPLL_CLK_EN,

				IMX6Q_GPR13_SATA_MPLL_CLK_EN);

		usleep_range(1000, 2000);

	}



	return 0;

}



static struct ahci_platform_data imx6q_sata_pdata = {

	.init = imx6q_sata_init,

	.exit = imx6q_sata_exit,

	.ata_port_info = &ahci_imx_port_info,

	.suspend = imx_ahci_suspend,

	.resume = imx_ahci_resume,

};



static const struct of_device_id imx_ahci_of_match[] = {
@@ -152,6 +247,8 @@ static int imx_ahci_probe(struct platform_device *pdev) 
	ahci_dev = &ahci_pdev->dev;

	ahci_dev->parent = dev;



	imxpriv->no_device = false;

	imxpriv->first_time = true;

	imxpriv->ahb_clk = devm_clk_get(dev, "ahb");

	if (IS_ERR(imxpriv->ahb_clk)) {

		dev_err(dev, "can't get ahb clock.\n");

drivers/ata/ahci_platform.c

+2 −1
Original line number Diff line number Diff line
@@ -49,10 +49,11 @@ static struct platform_device_id ahci_devtype[] = { 
};

MODULE_DEVICE_TABLE(platform, ahci_devtype);



static struct ata_port_operations ahci_platform_ops = {

struct ata_port_operations ahci_platform_ops = {

	.inherits	= &ahci_ops,

	.host_stop	= ahci_host_stop,

};

EXPORT_SYMBOL_GPL(ahci_platform_ops);



static struct ata_port_operations ahci_platform_retry_srst_ops = {

	.inherits	= &ahci_pmp_retry_srst_ops,

drivers/ata/libahci.c

+2 −2
Original line number Diff line number Diff line
@@ -89,7 +89,6 @@ static int ahci_pmp_retry_softreset(struct ata_link *link, unsigned int *class, 
static int ahci_hardreset(struct ata_link *link, unsigned int *class,

			  unsigned long deadline);

static void ahci_postreset(struct ata_link *link, unsigned int *class);

static void ahci_error_handler(struct ata_port *ap);

static void ahci_post_internal_cmd(struct ata_queued_cmd *qc);

static void ahci_dev_config(struct ata_device *dev);

#ifdef CONFIG_PM
@@ -1982,7 +1981,7 @@ static void ahci_thaw(struct ata_port *ap) 
	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);

}



static void ahci_error_handler(struct ata_port *ap)

void ahci_error_handler(struct ata_port *ap)

{

	if (!(ap->pflags & ATA_PFLAG_FROZEN)) {

		/* restart engine */
@@ -1995,6 +1994,7 @@ static void ahci_error_handler(struct ata_port *ap) 
	if (!ata_dev_enabled(ap->link.device))

		ahci_stop_engine(ap);

}

EXPORT_SYMBOL_GPL(ahci_error_handler);



static void ahci_post_internal_cmd(struct ata_queued_cmd *qc)

{

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