code.ossystems Code Review - meta-freescale.git/blob

   1 From 10df11bb736c8166e53b41f96688b2e6bd53773b Mon Sep 17 00:00:00 2001
   2 From: Richard Zhu <r65037@freescale.com>
   3 Date: Fri, 16 Dec 2011 10:08:04 +0800
   4 Subject: [PATCH] ENGR00170244-1 ARM: AHCI: Enable PDDQ mode when no disk is attached
   5
   6 In order to save the power consumption, enable the
   7 PDDQ mode of AHCI PHY when there is no sata disk
   8 on the port
   9
  10 Signed-off-by: Richard Zhu <r65037@freescale.com>
  11 (cherry picked from commit a53c29d7e484a3562e3a4f24d952485fbeb4c933)
  12 ---
  13  arch/arm/plat-mxc/ahci_sata.c              |   30 ++++++++++++++++++++-------
  14  arch/arm/plat-mxc/include/mach/ahci_sata.h |    1 +
  15  2 files changed, 23 insertions(+), 8 deletions(-)
  16
  17 diff --git a/arch/arm/plat-mxc/ahci_sata.c b/arch/arm/plat-mxc/ahci_sata.c
  18 index 466636b..76a2747 100644
  19 --- a/arch/arm/plat-mxc/ahci_sata.c
  20 +++ b/arch/arm/plat-mxc/ahci_sata.c
  21 @@ -156,7 +156,7 @@ static int sata_init(struct device *dev)
  22  {
  23         void __iomem *mmio;
  24         u32 tmpdata;
  25 -       int ret = 0;
  26 +       int ret = 0, iterations = 20;
  27         struct clk *clk;
  28
  29         sata_clk = clk_get(dev, "imx_sata_clk");
  30 @@ -281,14 +281,28 @@ static int sata_init(struct device *dev)
  31
  32         if (AHCI_SAVE_PWR_WITHOUT_HOTPLUG) {
  33                 /* Release resources when there is no device on the port */
  34 -               if ((readl(mmio + PORT_SATA_SR) & 0xF) == 0) {
  35 -                       ret = -ENODEV;
  36 -                       if (machine_is_mx53_smd() || machine_is_mx53_loco()
  37 -                               || board_is_mx53_ard_b())
  38 -                               goto no_device;
  39 +               do {
  40 +                       if ((readl(mmio + PORT_SATA_SR) & 0xF) == 0)
  41 +                               msleep(25);
  42                         else
  43 -                               goto release_mem;
  44 -               }
  45 +                               break;
  46 +
  47 +                       if (iterations == 0) {
  48 +                               pr_info("No sata disk.\n");
  49 +                               ret = -ENODEV;
  50 +                               /* Enter into PDDQ mode, save power */
  51 +                               tmpdata = readl(mmio + PORT_PHY_CTL);
  52 +                               writel(tmpdata | PORT_PHY_CTL_PDDQ_LOC,
  53 +                                                       mmio + PORT_PHY_CTL);
  54 +
  55 +                               if (machine_is_mx53_smd()
  56 +                                       || machine_is_mx53_loco()
  57 +                                       || board_is_mx53_ard_b())
  58 +                                       goto no_device;
  59 +                               else
  60 +                                       goto release_mem;
  61 +                       }
  62 +               } while (iterations-- > 0);
  63         }
  64
  65         iounmap(mmio);
  66 diff --git a/arch/arm/plat-mxc/include/mach/ahci_sata.h b/arch/arm/plat-mxc/include/mach/ahci_sata.h
  67 index ea68a19..e31797b 100644
  68 --- a/arch/arm/plat-mxc/include/mach/ahci_sata.h
  69 +++ b/arch/arm/plat-mxc/include/mach/ahci_sata.h
  70 @@ -37,6 +37,7 @@ enum {
  71         PORT_PHY_CTL_CAP_DAT_LOC = 0x20000,
  72         PORT_PHY_CTL_WRITE_LOC = 0x40000,
  73         PORT_PHY_CTL_READ_LOC = 0x80000,
  74 +       PORT_PHY_CTL_PDDQ_LOC = 0x100000,
  75         /* Port0 PHY Status */
  76         PORT_PHY_SR = 0x17c,
  77         /* PORT_PHY_SR */
  78 --
  79 1.5.4.4
  80