From 4cf27d2ec716fddacd02169af9a26a43ea52875e Mon Sep 17 00:00:00 2001 From: Roger Quadros Date: Fri, 29 Aug 2014 19:11:53 +0300 Subject: [PATCH] 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 Signed-off-by: Sekhar Nori Acked-by: Tony Lindgren --- arch/arm/mach-omap2/gpmc.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 0ba95d3e74e5..437fb6f6df52 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; -- 2.34.1