Hi Sascha:

Best Regards
Richard Zhu

-----Original Message-----
From: Sascha Hauer [mailto:s.hauer at pengutronix.de]
Sent: Tuesday, March 15, 2011 5:03 PM
To: Zhu Richard-R65037
Cc: linux-arm-kernel at lists.infradead.org; jgarzik at pobox.com;
kernel at pengutronix.de; linux-ide at vger.kernel.org;
avorontsov at ru.mvista.com; eric at eukrea.com; eric.miao at linaro.org
Subject: Re: [RFC PATCH 2/2] MX53 Enable the AHCI SATA on MX53 LOCO

On Mon, Mar 14, 2011 at 05:55:44PM +0800, Richard Zhu wrote:

quoted

Signed-off-by: Richard Zhu <redacted>
---
 arch/arm/mach-mx5/board-mx53_loco.c |  120
+++++++++++++++++++++++++++++++++++
 1 files changed, 120 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-mx5/board-mx53_loco.c

b/arch/arm/mach-mx5/board-mx53_loco.c
index 0a18f8d..9a7bbea 100644

--- a/arch/arm/mach-mx5/board-mx53_loco.c
+++ b/arch/arm/mach-mx5/board-mx53_loco.c

@@ -23,11 +23,13 @@
 #include <linux/fec.h>
 #include <linux/delay.h>
 #include <linux/gpio.h>
+#include <linux/ahci_platform.h>

 #include <mach/common.h>
 #include <mach/hardware.h>
 #include <mach/imx-uart.h>
 #include <mach/iomux-mx53.h>
+#include <mach/ahci_sata.h>

 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>

@@ -203,6 +205,123 @@ static const struct imxi2c_platform_data

mx53_loco_i2c_data __initconst = {

quoted

    .bitrate = 100000,
 };

+/* HW Initialization, if return 0, initialization is successful. */
+static int sata_init(struct device *dev, void __iomem *addr) {
+   void __iomem *mmio;
+   struct clk *clk;
+   int ret = 0;
+   u32 tmpdata;
+
+   clk = clk_get(dev, "imx_sata_clk");
+   ret = IS_ERR(clk);
+   if (ret) {
+           printk(KERN_ERR "IMX AHCI can't get clock.\n");
+           return ret;
+   }

IS_ERR returns 0 or 1 which is not a valid return value here.

Accepted.

quoted

+   ret = clk_enable(clk);
+   if (ret) {
+           printk(KERN_ERR "IMX AHCI can't enable clock.\n");

You have a struct device *, so you should use dev_err.

Accepted.

quoted

+           clk_put(clk);
+           return ret;
+   }
+
+   /* FSL IMX AHCI SATA uses the internal usb phy1 clk on loco */
+   clk = clk_get(dev, "usb_phy1");
+   ret = IS_ERR(clk);
+   if (ret) {
+           printk(KERN_ERR "IMX AHCI can't get USB PHY1 CLK.\n");
+           goto no_input_clk;
+   }
+   ret = clk_enable(clk);
+   if (ret) {
+           printk(KERN_ERR "IMX AHCI Can't enable USB PHY1 clock.\n");
+           clk_put(clk);
+           goto no_input_clk;
+   }
+
+   /* Get the AHB clock rate, and configure the TIMER1MS reg later */
+   clk = clk_get(NULL, "ahb_clk");
+   ret = IS_ERR(clk);
+   if (ret) {
+           printk(KERN_ERR "IMX AHCI can't get AHB clock.\n");
+           goto no_clk;
+   }
+
+   mmio = ioremap(MX53_SATA_BASE_ADDR, SZ_2K);
+   if (mmio == NULL) {
+           printk(KERN_ERR "Failed to map SATA REGS\n");
+           goto no_clk;
+   }
+
+   tmpdata = readl(mmio + HOST_CAP);
+   if (!(tmpdata & HOST_CAP_SSS)) {
+           tmpdata |= HOST_CAP_SSS;
+           writel(tmpdata, mmio + HOST_CAP);
+   }
+
+   if (!(readl(mmio + HOST_PORTS_IMPL) & 0x1))
+           writel((readl(mmio + HOST_PORTS_IMPL) | 0x1),
+                   mmio + HOST_PORTS_IMPL);
+
+   tmpdata = clk_get_rate(clk) / 1000;
+   writel(tmpdata, mmio + HOST_TIMER1MS);
+
+   iounmap(mmio);
+
+   return ret;
+
+no_clk:
+   clk = clk_get(dev, "usb_phy1");

While technically not strictly necessary at the moment you should balance
your clk_get / clk_put calls. Everything else is bad taste.

Yeah, you are right.
How do you think about add two clk pointers member into ahci_host_priv struct to balance
 clk_get/clk_put pair calls?
Or
Added one private pointer into ahci_host_priv to make a more flexible method for kinds of different platforms to
balance the hw resource(clk, power and so on) balance?

quoted

+   if (IS_ERR(clk)) {
+           clk = NULL;
+           printk(KERN_ERR "IMX AHCI can't get USB PHY1 CLK.\n");
+   } else {
+           clk_disable(clk);
+           clk_put(clk);
+   }
+
+no_input_clk:
+   clk = clk_get(dev, "imx_sata_clk");
+   if (IS_ERR(clk)) {
+           clk = NULL;
+           printk(KERN_ERR "IMX AHCI can't get clock.\n");
+   } else {
+           clk_disable(clk);
+           clk_put(clk);
+   }
+
+   return ret;
+}
+
+static void sata_exit(struct device *dev) {
+   struct clk *clk;
+
+   clk = clk_get(dev, "usb_phy1");
+   if (IS_ERR(clk)) {
+           clk = NULL;
+           printk(KERN_ERR "IMX AHCI can't get USB PHY1 CLK.\n");
+   } else {
+           clk_disable(clk);
+           clk_put(clk);
+   }
+
+   clk = clk_get(dev, "imx_sata_clk");
+   if (IS_ERR(clk)) {
+           clk = NULL;
+           printk(KERN_ERR "IMX AHCI can't get clock.\n");
+   } else {
+           clk_disable(clk);
+           clk_put(clk);
+   }
+}
+
+static struct ahci_platform_data sata_data = {
+   .init = sata_init,
+   .exit = sata_exit,
+};
+
 static void __init mx53_loco_board_init(void)  {
    mxc_iomux_v3_setup_multiple_pads(mx53_loco_pads,

@@ -215,6 +334,7 @@ static void __init mx53_loco_board_init(void)
    imx53_add_imx_i2c(1, &mx53_loco_i2c_data);
    imx53_add_sdhci_esdhc_imx(0, NULL);
    imx53_add_sdhci_esdhc_imx(2, NULL);
+   imx53_add_ahci_imx(0, &sata_data);
 }

 static void __init mx53_loco_timer_init(void)
--

1.7.1

--
Pengutronix e.K.                           |
|
Industrial Linux Solutions                 | http://www.pengutronix.de/
|
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0
|
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555
|