ENGR00170244-1 ARM: AHCI: Enable PDDQ mode when no disk is attached

In order to save the power consumption, enable the
PDDQ mode of AHCI PHY when there is no sata disk
on the port

Signed-off-by: Richard Zhu <r65037@freescale.com>

diff --git a/arch/arm/plat-mxc/ahci_sata.c b/arch/arm/plat-mxc/ahci_sata.c
index ab4fcf86bc4cbca3fe76d7e397d09b6b170a8cf0..0d78a123a4696939946ac21636f378ebe837dba0 100644 (file)
--- a/arch/arm/plat-mxc/ahci_sata.c
+++ b/arch/arm/plat-mxc/ahci_sata.c
@@ -22,6 +22,7 @@
 #include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
+#include <asm/errno.h>
 #include <mach/ahci_sata.h>
 
 int write_phy_ctl_ack_polling(u32 data, void __iomem *mmio,
@@ -37,7 +38,7 @@ int write_phy_ctl_ack_polling(u32 data, void __iomem *mmio,
                if (val == exp_val)
                        return 0;
                if (i == max_iterations) {
-                       printk(KERN_ERR "Wait for CR ACK error!\n");
+                       pr_err("Wait for CR ACK error!\n");
                        return 1;
                }
                usleep_range(100, 200);
@@ -137,6 +138,7 @@ int sata_phy_cr_read(u32 *data, void __iomem *mmio)
 int sata_init(void __iomem *addr, unsigned long timer1ms)
 {
        u32 tmpdata;
+       int iterations = 20;
 
        /* Reset HBA */
        writel(HOST_RESET, addr + HOST_CTL);
@@ -146,7 +148,7 @@ int sata_init(void __iomem *addr, unsigned long timer1ms)
        while (readl(addr + HOST_VERSIONR) == 0) {
                tmpdata++;
                if (tmpdata > 100000) {
-                       printk(KERN_ERR "Can't recover from RESET HBA!\n");
+                       pr_err("Can't recover from RESET HBA!\n");
                        break;
                }
        }
@@ -164,5 +166,22 @@ int sata_init(void __iomem *addr, unsigned long timer1ms)
 
        writel(timer1ms, addr + HOST_TIMER1MS);
 
+       /* Release resources when there is no device on the port */
+       do {
+               if ((readl(addr + PORT_SATA_SR) & 0xF) == 0)
+                       msleep(25);
+               else
+                       break;
+
+               if (iterations == 0) {
+                       pr_info("No sata disk.\n");
+                       /* Enter into PDDQ mode, save power */
+                       tmpdata = readl(addr + PORT_PHY_CTL);
+                       writel(tmpdata | PORT_PHY_CTL_PDDQ_LOC,
+                                       addr + PORT_PHY_CTL);
+                       return -ENODEV;
+               }
+       } while (iterations-- > 0);
+
        return 0;
 }

diff --git a/arch/arm/plat-mxc/include/mach/ahci_sata.h b/arch/arm/plat-mxc/include/mach/ahci_sata.h
index edca22b4fc04f0815aa74fa7752f915f3a05c56d..48b93e55eea0f2a785b71bf85c444b5ab93e3750 100755 (executable)
--- a/arch/arm/plat-mxc/include/mach/ahci_sata.h
+++ b/arch/arm/plat-mxc/include/mach/ahci_sata.h
@@ -39,6 +39,7 @@ enum {
        PORT_PHY_CTL_CAP_DAT_LOC = 0x20000,
        PORT_PHY_CTL_WRITE_LOC = 0x40000,
        PORT_PHY_CTL_READ_LOC = 0x80000,
+       PORT_PHY_CTL_PDDQ_LOC = 0x100000,
        /* Port0 PHY Status */
        PORT_PHY_SR = 0x17c,
        /* PORT_PHY_SR */