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author | Roger Quadros <rogerq@ti.com> | 2014-08-29 19:11:53 +0300 |
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committer | Roger Quadros <rogerq@ti.com> | 2014-10-30 17:21:46 +0200 |
commit | 4cf27d2ec716fddacd02169af9a26a43ea52875e (patch) | |
tree | 9c92e43a9629ce9393ab5f04559cb16eb79416de /arch/arm/mach-omap2/gpmc.c | |
parent | e378d22b9c27de4af4946e4e7928fef50f9a9ff7 (diff) | |
download | op-kernel-dev-4cf27d2ec716fddacd02169af9a26a43ea52875e.zip op-kernel-dev-4cf27d2ec716fddacd02169af9a26a43ea52875e.tar.gz |
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>
Diffstat (limited to 'arch/arm/mach-omap2/gpmc.c')
-rw-r--r-- | arch/arm/mach-omap2/gpmc.c | 34 |
1 files changed, 27 insertions, 7 deletions
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 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t) 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 @@ static int gpmc_cs_enable_mem(int cs, u32 base, u32 size) 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 @@ static int gpmc_cs_remap(int cs, u32 base) 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 @@ int gpmc_cs_request(int cs, unsigned long size, unsigned long *base) 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 @@ static int gpmc_probe_generic_child(struct platform_device *pdev, 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 @@ static int gpmc_probe_generic_child(struct platform_device *pdev, 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; |