diff options
author | Richard Zhu <r65037@freescale.com> | 2013-10-15 06:44:54 +0400 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2013-10-15 16:47:00 +0400 |
commit | 8b789d89813fae01908ecc825c9dfc0ec90647ad (patch) | |
tree | b14d0e8c5212e85f2d44fc9cde292ec5eb499a3a /drivers/ata/ahci_imx.c | |
parent | 89951f2245e5c31d6b74dea1570db716175a74fe (diff) | |
download | linux-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.c | 101 |
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"); |