From 6d3c55fd4f0f94a9455d30df9414ddb0f755f402 Mon Sep 17 00:00:00 2001 From: "Avinash.H.M" Date: Sun, 10 Jul 2011 05:27:16 -0600 Subject: [PATCH] OMAP: hwmod: fix the i2c-reset timeout during bootup The sequence of _ocp_softreset doesn't work for i2c. The i2c module has a special sequence to reset the module. The sequence is - Disable the I2C. - Write to SOFTRESET bit. - Enable the I2C. - Poll on the RESETDONE bit. The sequence is implemented as a function and the i2c_class is updated with the correct 'reset' pointer. omap_hwmod_softreset function is implemented which triggers the softreset by writing into sysconfig register. On following this sequence, i2c module resets properly and timeouts are not seen. Cc: Rajendra Nayak Cc: Paul Walmsley Cc: Benoit Cousson Cc: Kevin Hilman Signed-off-by: Avinash.H.M [paul@pwsan.com: combined this patch with a patch to remove HWMOD_INIT_NO_RESET from the 44xx hwmod flags; change register offset conditional code to use the IP block revision; minor code cleanup] Signed-off-by: Paul Walmsley --- arch/arm/mach-omap2/i2c.c | 68 ++++++++++++++++++++ arch/arm/mach-omap2/omap_hwmod.c | 27 ++++++++ arch/arm/mach-omap2/omap_hwmod_2420_data.c | 1 + arch/arm/mach-omap2/omap_hwmod_2430_data.c | 1 + arch/arm/mach-omap2/omap_hwmod_3xxx_data.c | 7 +- arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 10 +-- arch/arm/plat-omap/include/plat/i2c.h | 3 + arch/arm/plat-omap/include/plat/omap_hwmod.h | 1 + 8 files changed, 111 insertions(+), 7 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 #include +#include +#include #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; +} diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 7d242c9e2a2c..02b6016393a8 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1655,6 +1655,33 @@ void omap_hwmod_write(u32 v, struct omap_hwmod *oh, u16 reg_offs) __raw_writel(v, oh->_mpu_rt_va + reg_offs); } +/** + * omap_hwmod_softreset - reset a module via SYSCONFIG.SOFTRESET bit + * @oh: struct omap_hwmod * + * + * This is a public function exposed to drivers. Some drivers may need to do + * some settings before and after resetting the device. Those drivers after + * doing the necessary settings could use this function to start a reset by + * setting the SYSCONFIG.SOFTRESET bit. + */ +int omap_hwmod_softreset(struct omap_hwmod *oh) +{ + u32 v; + int ret; + + if (!oh || !(oh->_sysc_cache)) + return -EINVAL; + + v = oh->_sysc_cache; + ret = _set_softreset(oh, &v); + if (ret) + goto error; + _write_sysconfig(v, oh); + +error: + return ret; +} + /** * omap_hwmod_set_slave_idlemode - set the hwmod's OCP slave idlemode * @oh: struct omap_hwmod * diff --git a/arch/arm/mach-omap2/omap_hwmod_2420_data.c b/arch/arm/mach-omap2/omap_hwmod_2420_data.c index 7af251448a7e..a015c69068f6 100644 --- a/arch/arm/mach-omap2/omap_hwmod_2420_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_2420_data.c @@ -1030,6 +1030,7 @@ static struct omap_hwmod_class i2c_class = { .name = "i2c", .sysc = &i2c_sysc, .rev = OMAP_I2C_IP_VERSION_1, + .reset = &omap_i2c_reset, }; static struct omap_i2c_dev_attr i2c_dev_attr = { diff --git a/arch/arm/mach-omap2/omap_hwmod_2430_data.c b/arch/arm/mach-omap2/omap_hwmod_2430_data.c index 405688ae265b..16743c7d6e8e 100644 --- a/arch/arm/mach-omap2/omap_hwmod_2430_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_2430_data.c @@ -1079,6 +1079,7 @@ static struct omap_hwmod_class i2c_class = { .name = "i2c", .sysc = &i2c_sysc, .rev = OMAP_I2C_IP_VERSION_1, + .reset = &omap_i2c_reset, }; static struct omap_i2c_dev_attr i2c_dev_attr = { diff --git a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c index c704ac8ca6bb..25bf43b5a4ec 100644 --- a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c @@ -1306,9 +1306,10 @@ static struct omap_hwmod omap3xxx_uart4_hwmod = { }; static struct omap_hwmod_class i2c_class = { - .name = "i2c", - .sysc = &i2c_sysc, - .rev = OMAP_I2C_IP_VERSION_1, + .name = "i2c", + .sysc = &i2c_sysc, + .rev = OMAP_I2C_IP_VERSION_1, + .reset = &omap_i2c_reset, }; static struct omap_hwmod_dma_info omap3xxx_dss_sdma_chs[] = { diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c index 55331df4e452..5d5df49749df 100644 --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c @@ -22,6 +22,7 @@ #include #include +#include #include #include #include @@ -2162,6 +2163,7 @@ static struct omap_hwmod_class omap44xx_i2c_hwmod_class = { .name = "i2c", .sysc = &omap44xx_i2c_sysc, .rev = OMAP_I2C_IP_VERSION_2, + .reset = &omap_i2c_reset, }; static struct omap_i2c_dev_attr i2c_dev_attr = { @@ -2207,7 +2209,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c1_slaves[] = { static struct omap_hwmod omap44xx_i2c1_hwmod = { .name = "i2c1", .class = &omap44xx_i2c_hwmod_class, - .flags = HWMOD_16BIT_REG | HWMOD_INIT_NO_RESET, + .flags = HWMOD_16BIT_REG, .mpu_irqs = omap44xx_i2c1_irqs, .sdma_reqs = omap44xx_i2c1_sdma_reqs, .main_clk = "i2c1_fck", @@ -2261,7 +2263,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c2_slaves[] = { static struct omap_hwmod omap44xx_i2c2_hwmod = { .name = "i2c2", .class = &omap44xx_i2c_hwmod_class, - .flags = HWMOD_16BIT_REG | HWMOD_INIT_NO_RESET, + .flags = HWMOD_16BIT_REG, .mpu_irqs = omap44xx_i2c2_irqs, .sdma_reqs = omap44xx_i2c2_sdma_reqs, .main_clk = "i2c2_fck", @@ -2315,7 +2317,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c3_slaves[] = { static struct omap_hwmod omap44xx_i2c3_hwmod = { .name = "i2c3", .class = &omap44xx_i2c_hwmod_class, - .flags = HWMOD_16BIT_REG | HWMOD_INIT_NO_RESET, + .flags = HWMOD_16BIT_REG, .mpu_irqs = omap44xx_i2c3_irqs, .sdma_reqs = omap44xx_i2c3_sdma_reqs, .main_clk = "i2c3_fck", @@ -2369,7 +2371,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c4_slaves[] = { static struct omap_hwmod omap44xx_i2c4_hwmod = { .name = "i2c4", .class = &omap44xx_i2c_hwmod_class, - .flags = HWMOD_16BIT_REG | HWMOD_INIT_NO_RESET, + .flags = HWMOD_16BIT_REG, .mpu_irqs = omap44xx_i2c4_irqs, .sdma_reqs = omap44xx_i2c4_sdma_reqs, .main_clk = "i2c4_fck", diff --git a/arch/arm/plat-omap/include/plat/i2c.h b/arch/arm/plat-omap/include/plat/i2c.h index fd75dadfa89c..7c22b9e10dc3 100644 --- a/arch/arm/plat-omap/include/plat/i2c.h +++ b/arch/arm/plat-omap/include/plat/i2c.h @@ -53,4 +53,7 @@ struct omap_i2c_dev_attr { void __init omap1_i2c_mux_pins(int bus_id); void __init omap2_i2c_mux_pins(int bus_id); +struct omap_hwmod; +int omap_i2c_reset(struct omap_hwmod *oh); + #endif /* __ASM__ARCH_OMAP_I2C_H */ diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h index ce06ac6a9709..fafdfe3c8d4e 100644 --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h @@ -566,6 +566,7 @@ void omap_hwmod_ocp_barrier(struct omap_hwmod *oh); void omap_hwmod_write(u32 v, struct omap_hwmod *oh, u16 reg_offs); u32 omap_hwmod_read(struct omap_hwmod *oh, u16 reg_offs); +int omap_hwmod_softreset(struct omap_hwmod *oh); int omap_hwmod_count_resources(struct omap_hwmod *oh); int omap_hwmod_fill_resources(struct omap_hwmod *oh, struct resource *res); -- 2.39.2