diff options
author | Tejun Heo <tj@kernel.org> | 2011-11-28 09:46:22 -0800 |
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committer | Tejun Heo <tj@kernel.org> | 2011-11-28 09:46:22 -0800 |
commit | d4bbf7e7759afc172e2bfbc5c416324590049cdd (patch) | |
tree | 7eab5ee5481cd3dcf1162329fec827177640018a /arch/arm/mach-omap2/i2c.c | |
parent | a150439c4a97db379f0ed6faa46fbbb6e7bf3cb2 (diff) | |
parent | 401d0069cb344f401bc9d264c31db55876ff78c0 (diff) |
Merge branch 'master' into x86/memblock
Conflicts & resolutions:
* arch/x86/xen/setup.c
dc91c728fd "xen: allow extra memory to be in multiple regions"
24aa07882b "memblock, x86: Replace memblock_x86_reserve/free..."
conflicted on xen_add_extra_mem() updates. The resolution is
trivial as the latter just want to replace
memblock_x86_reserve_range() with memblock_reserve().
* drivers/pci/intel-iommu.c
166e9278a3f "x86/ia64: intel-iommu: move to drivers/iommu/"
5dfe8660a3d "bootmem: Replace work_with_active_regions() with..."
conflicted as the former moved the file under drivers/iommu/.
Resolved by applying the chnages from the latter on the moved
file.
* mm/Kconfig
6661672053a "memblock: add NO_BOOTMEM config symbol"
c378ddd53f9 "memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option"
conflicted trivially. Both added config options. Just
letting both add their own options resolves the conflict.
* mm/memblock.c
d1f0ece6cdc "mm/memblock.c: small function definition fixes"
ed7b56a799c "memblock: Remove memblock_memory_can_coalesce()"
confliected. The former updates function removed by the
latter. Resolution is trivial.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'arch/arm/mach-omap2/i2c.c')
-rw-r--r-- | arch/arm/mach-omap2/i2c.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/i2c.c b/arch/arm/mach-omap2/i2c.c index 79c478c4cb1c..ace99944e96f 100644 --- a/arch/arm/mach-omap2/i2c.c +++ b/arch/arm/mach-omap2/i2c.c @@ -21,9 +21,19 @@ #include <plat/cpu.h> #include <plat/i2c.h> +#include <plat/common.h> +#include <plat/omap_hwmod.h> #include "mux.h" +/* In register I2C_CON, Bit 15 is the I2C enable bit */ +#define I2C_EN BIT(15) +#define OMAP2_I2C_CON_OFFSET 0x24 +#define OMAP4_I2C_CON_OFFSET 0xA4 + +/* Maximum microseconds to wait for OMAP module to softreset */ +#define MAX_MODULE_SOFTRESET_WAIT 10000 + void __init omap2_i2c_mux_pins(int bus_id) { char mux_name[sizeof("i2c2_scl.i2c2_scl")]; @@ -37,3 +47,61 @@ void __init omap2_i2c_mux_pins(int bus_id) sprintf(mux_name, "i2c%i_sda.i2c%i_sda", bus_id, bus_id); omap_mux_init_signal(mux_name, OMAP_PIN_INPUT); } + +/** + * omap_i2c_reset - reset the omap i2c module. + * @oh: struct omap_hwmod * + * + * The i2c moudle in omap2, omap3 had a special sequence to reset. The + * sequence is: + * - Disable the I2C. + * - Write to SOFTRESET bit. + * - Enable the I2C. + * - Poll on the RESETDONE bit. + * The sequence is implemented in below function. This is called for 2420, + * 2430 and omap3. + */ +int omap_i2c_reset(struct omap_hwmod *oh) +{ + u32 v; + u16 i2c_con; + int c = 0; + + if (oh->class->rev == OMAP_I2C_IP_VERSION_2) { + i2c_con = OMAP4_I2C_CON_OFFSET; + } else if (oh->class->rev == OMAP_I2C_IP_VERSION_1) { + i2c_con = OMAP2_I2C_CON_OFFSET; + } else { + WARN(1, "Cannot reset I2C block %s: unsupported revision\n", + oh->name); + return -EINVAL; + } + + /* Disable I2C */ + v = omap_hwmod_read(oh, i2c_con); + v &= ~I2C_EN; + omap_hwmod_write(v, oh, i2c_con); + + /* Write to the SOFTRESET bit */ + omap_hwmod_softreset(oh); + + /* Enable I2C */ + v = omap_hwmod_read(oh, i2c_con); + v |= I2C_EN; + omap_hwmod_write(v, oh, i2c_con); + + /* Poll on RESETDONE bit */ + omap_test_timeout((omap_hwmod_read(oh, + oh->class->sysc->syss_offs) + & SYSS_RESETDONE_MASK), + MAX_MODULE_SOFTRESET_WAIT, c); + + if (c == MAX_MODULE_SOFTRESET_WAIT) + pr_warning("%s: %s: softreset failed (waited %d usec)\n", + __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT); + else + pr_debug("%s: %s: softreset in %d usec\n", __func__, + oh->name, c); + + return 0; +} |