[U-Boot] [PATCH 6/9] MX53: add function to set SATA clock to internal

Stefano Babic
2012-02-22T10:24:38Z

The MX53 SATA interface can use an internal clock (USB PHY1)
instead of an external clock. This is an undocumented feature, but used
on most Freescale's evaluation boards, such as MX53-loco.

As stated by Freescale's support:

Fuses (but not pins) may be used to configure SATA clocks.
Particularly the i.MX53 Fuse_Map contains the next information
about configuring SATA clocks :
SATA_ALT_REF_CLK[1:0] (offset 0x180C)

'00' - 100MHz (External)
'01' - 50MHz (External)
'10' - 120MHz, internal (USB PHY)
'11' - Reserved

Signed-off-by: Stefano Babic <sbabic@denx.de>
CC: Fabio Estevam <fabio.estevam@freescale.com>
---
arch/arm/cpu/armv7/mx5/clock.c | 24 ++++++++++++++++++++++++
arch/arm/include/asm/arch-mx5/clock.h | 1 +
2 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/armv7/mx5/clock.c b/arch/arm/cpu/armv7/mx5/clock.c
index 8f8d01c..d769a4d 100644
--- a/arch/arm/cpu/armv7/mx5/clock.c
+++ b/arch/arm/cpu/armv7/mx5/clock.c
@@ -399,6 +399,30 @@ u32 imx_get_fecclk(void)
return mxc_get_clock(MXC_IPG_CLK);
}

+#ifdef CONFIG_MX53
+/*
+ * The clock for the external interface can be set to use internal clock
+ * if fuse bank 4, row 3, bit 2 is set.
+ * This is an undocumented feature and it was confirmed by Freescale's support:
+ * Fuses (but not pins) may be used to configure SATA clocks.
+ * Particularly the i.MX53 Fuse_Map contains the next information
+ * about configuring SATA clocks : SATA_ALT_REF_CLK[1:0] (offset 0x180C)
+ * '00' - 100MHz (External)
+ * '01' - 50MHz (External)
+ * '10' - 120MHz, internal (USB PHY)
+ * '11' - Reserved
+*/
+void mxc_set_sata_internal_clock(void)
+{
+ u32 *tmp_base =
+ (u32 *)(IIM_BASE_ADDR + 0x180c);
+
+ set_usb_phy1_clk();
+
+ writel((readl(tmp_base) & (~0x7)) | 0x4, tmp_base);
+}
+#endif
+
/*
* Dump some core clockes.
*/
diff --git a/arch/arm/include/asm/arch-mx5/clock.h b/arch/arm/include/asm/arch-mx5/clock.h
index f9f82f3..e822809 100644
--- a/arch/arm/include/asm/arch-mx5/clock.h
+++ b/arch/arm/include/asm/arch-mx5/clock.h
@@ -45,5 +45,6 @@ void set_usb_phy2_clk(void);
void enable_usb_phy2_clk(unsigned char enable);
void set_usboh3_clk(void);
void enable_usboh3_clk(unsigned char enable);
+void mxc_set_sata_internal_clock(void);

#endif /* __ASM_ARCH_CLOCK_H */
--
1.7.5.4