ARM: OMAP2+: gpmc: Keep Chip Select disabled while configuring it
As per the OMAP reference manual [1], the Chip Select must be
disabled (i.e. CSVALID is 0) while configuring any of the
Chip select parameters.
[1] - 10.1.5.1 Chip-Select Base Address and Region Size Configuration
http://www.ti.com/lit/pdf/swpu177
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 0ba95d3..437fb6f 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -397,7 +397,7 @@
return 0;
}
-static int gpmc_cs_enable_mem(int cs, u32 base, u32 size)
+static int gpmc_cs_set_memconf(int cs, u32 base, u32 size)
{
u32 l;
u32 mask;
@@ -421,6 +421,15 @@
return 0;
}
+static void gpmc_cs_enable_mem(int cs)
+{
+ u32 l;
+
+ l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+ l |= GPMC_CONFIG7_CSVALID;
+ gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
+}
+
static void gpmc_cs_disable_mem(int cs)
{
u32 l;
@@ -532,18 +541,18 @@
gpmc_cs_get_memconf(cs, &old_base, &size);
if (base == old_base)
return 0;
- gpmc_cs_disable_mem(cs);
+
ret = gpmc_cs_delete_mem(cs);
if (ret < 0)
return ret;
+
ret = gpmc_cs_insert_mem(cs, base, size);
if (ret < 0)
return ret;
- ret = gpmc_cs_enable_mem(cs, base, size);
- if (ret < 0)
- return ret;
- return 0;
+ ret = gpmc_cs_set_memconf(cs, base, size);
+
+ return ret;
}
int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
@@ -572,12 +581,17 @@
if (r < 0)
goto out;
- r = gpmc_cs_enable_mem(cs, res->start, resource_size(res));
+ /* Disable CS while changing base address and size mask */
+ gpmc_cs_disable_mem(cs);
+
+ r = gpmc_cs_set_memconf(cs, res->start, resource_size(res));
if (r < 0) {
release_resource(res);
goto out;
}
+ /* Enable CS */
+ gpmc_cs_enable_mem(cs);
*base = res->start;
gpmc_cs_set_reserved(cs, 1);
out:
@@ -1539,6 +1553,9 @@
goto no_timings;
}
+ /* CS must be disabled while making changes to gpmc configuration */
+ gpmc_cs_disable_mem(cs);
+
/*
* FIXME: gpmc_cs_request() will map the CS to an arbitary
* location in the gpmc address space. When booting with
@@ -1577,6 +1594,9 @@
val &= ~GPMC_CONFIG_LIMITEDADDRESS;
gpmc_write_reg(GPMC_CONFIG, val);
+ /* Enable CS region */
+ gpmc_cs_enable_mem(cs);
+
no_timings:
if (of_platform_device_create(child, NULL, &pdev->dev))
return 0;