diff mbox

ARM: PXA3xx: program the CSMSADRCFG register

Message ID 1358077787-31518-1-git-send-email-grinberg@compulab.co.il (mailing list archive)
State New, archived
Headers show

Commit Message

Igor Grinberg Jan. 13, 2013, 11:49 a.m. UTC
The Chip Select Configuration Register must be programmed to 0x2 in
order to achieve the correct behavior of the Static Memory Controller.

Without this patch devices wired to DFI and accessed through SMC cannot
be accessed after resume from S2.

Do not rely on the boot loader to program the CSMSADRCFG register by
programming it in the kernel smemc module.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Cc: stable@vger.kernel.org
---
 arch/arm/mach-pxa/include/mach/smemc.h |    1 +
 arch/arm/mach-pxa/smemc.c              |   15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletions(-)

Comments

Eric Miao Jan. 15, 2013, 3:01 a.m. UTC | #1
On Sun, Jan 13, 2013 at 7:49 PM, Igor Grinberg <grinberg@compulab.co.il> wrote:
> The Chip Select Configuration Register must be programmed to 0x2 in
> order to achieve the correct behavior of the Static Memory Controller.
>
> Without this patch devices wired to DFI and accessed through SMC cannot
> be accessed after resume from S2.
>
> Do not rely on the boot loader to program the CSMSADRCFG register by
> programming it in the kernel smemc module.
>

Looks good to me. Acked-by: Eric Miao <eric.y.miao@gmail.com>

> Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
> Cc: stable@vger.kernel.org
> ---
>  arch/arm/mach-pxa/include/mach/smemc.h |    1 +
>  arch/arm/mach-pxa/smemc.c              |   15 ++++++++++++++-
>  2 files changed, 15 insertions(+), 1 deletions(-)
Haojian Zhuang Jan. 23, 2013, 8:51 a.m. UTC | #2
On Tue, Jan 15, 2013 at 11:01 AM, Eric Miao <eric.y.miao@gmail.com> wrote:
>
> On Sun, Jan 13, 2013 at 7:49 PM, Igor Grinberg <grinberg@compulab.co.il> wrote:
> > The Chip Select Configuration Register must be programmed to 0x2 in
> > order to achieve the correct behavior of the Static Memory Controller.
> >
> > Without this patch devices wired to DFI and accessed through SMC cannot
> > be accessed after resume from S2.
> >
> > Do not rely on the boot loader to program the CSMSADRCFG register by
> > programming it in the kernel smemc module.
> >
>
> Looks good to me. Acked-by: Eric Miao <eric.y.miao@gmail.com>
>

Appled.

Thanks.
Haojian
diff mbox

Patch

diff --git a/arch/arm/mach-pxa/include/mach/smemc.h b/arch/arm/mach-pxa/include/mach/smemc.h
index b7de471..b802f28 100644
--- a/arch/arm/mach-pxa/include/mach/smemc.h
+++ b/arch/arm/mach-pxa/include/mach/smemc.h
@@ -37,6 +37,7 @@ 
 #define CSADRCFG1	(SMEMC_VIRT + 0x84)  /* Address Configuration Register for CS1 */
 #define CSADRCFG2	(SMEMC_VIRT + 0x88)  /* Address Configuration Register for CS2 */
 #define CSADRCFG3	(SMEMC_VIRT + 0x8C)  /* Address Configuration Register for CS3 */
+#define CSMSADRCFG	(SMEMC_VIRT + 0xA0)  /* Chip Select Configuration Register */
 
 /*
  * More handy macros for PCMCIA
diff --git a/arch/arm/mach-pxa/smemc.c b/arch/arm/mach-pxa/smemc.c
index 7992305..f38aa89 100644
--- a/arch/arm/mach-pxa/smemc.c
+++ b/arch/arm/mach-pxa/smemc.c
@@ -40,6 +40,8 @@  static void pxa3xx_smemc_resume(void)
 	__raw_writel(csadrcfg[1], CSADRCFG1);
 	__raw_writel(csadrcfg[2], CSADRCFG2);
 	__raw_writel(csadrcfg[3], CSADRCFG3);
+	/* CSMSADRCFG wakes up in its default state (0), so we need to set it */
+	__raw_writel(0x2, CSMSADRCFG);
 }
 
 static struct syscore_ops smemc_syscore_ops = {
@@ -49,8 +51,19 @@  static struct syscore_ops smemc_syscore_ops = {
 
 static int __init smemc_init(void)
 {
-	if (cpu_is_pxa3xx())
+	if (cpu_is_pxa3xx()) {
+		/*
+		 * The only documentation we have on the
+		 * Chip Select Configuration Register (CSMSADRCFG) is that
+		 * it must be programmed to 0x2.
+		 * Moreover, in the bit definitions, the second bit
+		 * (CSMSADRCFG[1]) is called "SETALWAYS".
+		 * Other bits are reserved in this register.
+		 */
+		__raw_writel(0x2, CSMSADRCFG);
+
 		register_syscore_ops(&smemc_syscore_ops);
+	}
 
 	return 0;
 }