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authorRichard Zhu <r65037@freescale.com>2013-10-15 06:44:54 +0400
committerTejun Heo <tj@kernel.org>2013-10-15 16:47:00 +0400
commit8b789d89813fae01908ecc825c9dfc0ec90647ad (patch)
treeb14d0e8c5212e85f2d44fc9cde292ec5eb499a3a /drivers/ata/ahci_imx.c
parent89951f2245e5c31d6b74dea1570db716175a74fe (diff)
downloadlinux-8b789d89813fae01908ecc825c9dfc0ec90647ad.tar.xz
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: Richard Zhu <r65037@freescale.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/ata/ahci_imx.c')
-rw-r--r--drivers/ata/ahci_imx.c101
1 files changed, 99 insertions, 2 deletions
diff --git a/drivers/ata/ahci_imx.c b/drivers/ata/ahci_imx.c
index 58debb0acc3a..ae2d73fe321e 100644
--- a/drivers/ata/ahci_imx.c
+++ b/drivers/ata/ahci_imx.c
@@ -1,6 +1,6 @@
/*
+ * 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
*
@@ -25,10 +25,13 @@
#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 {
- HOST_TIMER1MS = 0xe0, /* Timer 1-ms */
+ PORT_PHY_CTL = 0x178, /* Port0 PHY Control */
+ PORT_PHY_CTL_PDDQ_LOC = 0x100000, /* PORT_PHY_CTL bits */
+ HOST_TIMER1MS = 0xe0, /* Timer 1-ms */
};
struct imx_ahci_priv {
@@ -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");