Hello,
On Fri, Sep 27, 2013 at 04:07:45PM +0800, Richard Zhu wrote:
> +config AHCI_IMX_PHY_POWER_DOWN_MODE
> + bool "Power saving mode when there is no SATA DEV detected on the port"
> + depends on AHCI_IMX
> + help
> + This option enable the power down mode of the imx ahci when there is
> + no sata device detected on the port, the sata port wouldn't be
> + functional anymore except one system power down, and power up again.
The last part of the sentence is a bit difficult to understand. Also,
I'm not sure whether making this a build option is a good idea.
Please read on.
> @@ -105,6 +110,36 @@ static int imx6q_sata_init(struct device *dev, void __iomem *mmio)
> reg_val = clk_get_rate(imxpriv->ahb_clk) / 1000;
> writel(reg_val, mmio + HOST_TIMER1MS);
>
> + if (IS_ENABLED(CONFIG_AHCI_IMX_PHY_POWER_DOWN_MODE)) {
> + /*
> + * In order to save power consumption, enter PDDQ mode
> + * when there is no device detected on the port
> + */
> + do {
> + sstatus = readl(mmio + 0x100 + PORT_SCR_STAT);
> + if ((sstatus & 0xF) == 0)
> + usleep_range(1000, 2000);
> + else
> + break;
> +
> + if (iterations == 0) {
> + pr_info("No sata disk.\n");
> + 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 = 1;
> +
> + return 0;
> + }
> + } while (iterations-- > 0);
> + } else {
> + imxpriv->no_device = 0;
> + }
This looks like it really should be part of lpm framework. Allow the
ahci_platform driver to override set_lpm() and turning off PHY if
MIN_POWER && !dev should work, right?
Thanks.
--
tejun
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