From: Pekon Gupta <pekon@xxxxxx>
Each GPMC chip-select needs to be configured for (base-address,CS-size) so that
GPMC understands the address-space allocated to device connected externally.
These chip-select configurations (base-address, CS-size) follow some basic
mapping rules like:
- The CS size is programmable from 256 MBytes to 16 MBytes (must be a power of 2)
and is defined by the mask field. Attached memory smaller than the programmed
CS region size is accessed through the entire CS region (aliasing).
- The programmed 'base-address' must be aligned to the 'CS-size' boundary and
be a power of 2.
- Valid CS-size values are {256MB(max), 128MB, 64MB, 32MB and 16MB (min)}
Any intermediate values creates holes in the chip-select memory-map.
This patch adds above checks in gpmc_cs_remap() so that any invalid value
passed by DT <reg> property can be filtered before actually allocating the
address space.
[rogerq@xxxxxx] typo and print message fixes.
Signed-off-by: Pekon Gupta <pekon@xxxxxx>
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
arch/arm/mach-omap2/gpmc.c | 51 +++++++++++++++++++++++++++++++++-------------
1 file changed, 37 insertions(+), 14 deletions(-)
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 8bc1338..793f3a9 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -516,31 +516,54 @@ static int gpmc_cs_delete_mem(int cs)
* gpmc_cs_remap - remaps a chip-select physical base address
* @cs: chip-select to remap
* @base: physical base address to re-map chip-select to
+ * @size: size of the chip select map
*
* Re-maps a chip-select to a new physical base address specified by
* "base". Returns 0 on success and appropriate negative error code
- * on failure.
+ * on failure. "size" of the map must be either 16M, 32M, 64M or 128M.
*/
-static int gpmc_cs_remap(int cs, u32 base)
+static int gpmc_cs_remap(int cs, u32 base, u32 size)
{
int ret;
- u32 old_base, size;
if (cs > gpmc_cs_num) {
pr_err("%s: requested chip-select is disabled\n", __func__);
return -ENODEV;
}
- /*
- * Make sure we ignore any device offsets from the GPMC partition
- * allocated for the chip select and that the new base confirms
- * to the GPMC 16MB minimum granularity.
- */
- base &= ~(SZ_16M - 1);
-
- gpmc_cs_get_memconf(cs, &old_base, &size);
- if (base == old_base)
- return 0;
+ /* Align size to meet SoC limitations */
+ if (size > SZ_256M) {
+ pr_err("%s: CS memory map > 256MB not supported\n", __func__);
+ return -ENODEV;
+ } else if (size > SZ_128M) {
+ WARN((size != SZ_256M), "%s: cs=%d: allocating 256MB\n",
+ __func__, cs);
+ size = SZ_256M;
+ } else if (size > SZ_64M) {
+ WARN((size != SZ_128M), "%s: cs=%d: allocating 128MB\n",
+ __func__, cs);
+ size = SZ_128M;
+ } else if (size > SZ_32M) {
+ WARN((size != SZ_64M), "%s: cs=%d: allocating 64MB\n",
+ __func__, cs);
+ size = SZ_64M;
+ } else if (size > SZ_16M) {
+ WARN((size != SZ_32M), "%s: cs=%d: allocating 32MB\n",
+ __func__, cs);
+ size = SZ_32M;
+ } else {
+ WARN((size != SZ_16M), "%s: cs=%d: allocating 16MB\n",
+ __func__, cs);
+ size = SZ_16M;
+ }
+
+ /* base address should be aligned with address-space size */
+ if (base & (size - 1)) {
+ pr_err("%s: cs base-addr: %x should be aligned to cs size: %x",
+ __func__, base, size);
+ return -EINVAL;
+ }
+
gpmc_cs_disable_mem(cs);
ret = gpmc_cs_delete_mem(cs);
if (ret < 0)
@@ -1551,7 +1574,7 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
* CS to this location. Once DT migration is complete should
* just make gpmc_cs_request() map a specific address.
*/
- ret = gpmc_cs_remap(cs, res.start);
+ ret = gpmc_cs_remap(cs, res.start, resource_size(&res));
if (ret < 0) {
dev_err(&pdev->dev, "cannot remap GPMC CS %d to %pa\n",
cs, &res.start);
--
1.8.3.2
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