Tony,
> -----Original Message-----
> From: Sonasath, Moiz
> Sent: Friday, February 26, 2010 1:15 PM
> To: linux-omap@xxxxxxxxxxxxxxx
> Cc: tony@xxxxxxxxxxx; Sonasath, Moiz; Pais, Allen; Pandita, Vikram
> Subject: [PATCH V3 2/2]OMAP: Disable internal I2C pull-ups in OMAP3630
>
> From: Moiz Sonasath <m-sonasath@xxxxxx>
>
> This patch disables the newly introduced internal pull-up feature in
> OMAP3630, to use only the external HW resitor >= 470 Ohm for the
> assured functionality in HS mode.
>
> While testing the I2C in High Speed mode, it was discovered that
> without a proper pull-up resitor, there is data corruption during
> multi-byte transfers. RTC(time_set) test case was used for testing.
>
> From the analysis done, it was concluded that ideally we need a pull-up
> of 1.6 K Ohm (recomended) or atleast 470 Ohm or greater for assured
> performance in HS mode.
>
> Signed-off-by: Moiz Sonasath <m-sonasath@xxxxxx>
> Signed-off-by: Allen Pais <allen.pais@xxxxxx>
> Signed-off-by: Vikram Pandita <vikram.pandita@xxxxxx>
I did resend this patch as per our last conversation, Can you please take this patch in?
> ---
> arch/arm/mach-omap2/i2c.c | 24 ++++++++++++++++++++++++
> arch/arm/plat-omap/include/plat/control.h | 14 ++++++++++++++
> 2 files changed, 38 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/i2c.c b/arch/arm/mach-omap2/i2c.c
> index 789ca8c..2e6eb28 100644
> --- a/arch/arm/mach-omap2/i2c.c
> +++ b/arch/arm/mach-omap2/i2c.c
> @@ -22,6 +22,7 @@
> #include <plat/cpu.h>
> #include <plat/i2c.h>
> #include <plat/mux.h>
> +#include <plat/control.h>
>
> #include "mux.h"
>
> @@ -52,5 +53,28 @@ int __init omap_register_i2c_bus(int bus_id, u32
> clkrate,
> omap_mux_init_signal(mux_name, OMAP_PIN_INPUT);
> }
>
> + /* Disable OMAP 3630 internal pull-ups for all I2Ci */
> + if (cpu_is_omap3630() &&
> !(omap_ctrl_readl(OMAP343X_CONTROL_PROG_IO1) &
> OMAP3630_PRG_I2C1_PULLUPRESX)) {
> +
> + u32 prog_io;
> +
> + prog_io = omap_ctrl_readl(OMAP343X_CONTROL_PROG_IO1);
> + /* Program (bit 19)=1 to disable internal pull-up on I2C1 */
> + prog_io |= OMAP3630_PRG_I2C1_PULLUPRESX;
> + /* Program (bit 0)=1 to disable internal pull-up on I2C2 */
> + prog_io |= OMAP3630_PRG_I2C2_PULLUPRESX;
> + omap_ctrl_writel(prog_io, OMAP343X_CONTROL_PROG_IO1);
> +
> + prog_io = omap_ctrl_readl(OMAP36XX_CONTROL_PROG_IO2);
> + /* Program (bit 7)=1 to disable internal pull-up on I2C3 */
> + prog_io |= OMAP3630_PRG_I2C3_PULLUPRESX;
> + omap_ctrl_writel(prog_io, OMAP36XX_CONTROL_PROG_IO2);
> +
> + prog_io = omap_ctrl_readl(OMAP36XX_CONTROL_PROG_IO_WKUP1);
> + /* Program (bit 5)=1 to disable internall pull-up on I2C4(SR)
> */
> + prog_io |= OMAP3630_PRG_SR_PULLUPRESX;
> + omap_ctrl_writel(prog_io, OMAP36XX_CONTROL_PROG_IO_WKUP1);
> + }
> +
> return omap_plat_register_i2c_bus(bus_id, clkrate, info, len);
> }
> diff --git a/arch/arm/plat-omap/include/plat/control.h b/arch/arm/plat-
> omap/include/plat/control.h
> index 2074473..9e58d8e 100644
> --- a/arch/arm/plat-omap/include/plat/control.h
> +++ b/arch/arm/plat-omap/include/plat/control.h
> @@ -169,6 +169,9 @@
> #define AM35XX_CONTROL_IP_SW_RESET (OMAP2_CONTROL_GENERAL + 0x0328)
> #define AM35XX_CONTROL_IPSS_CLK_CTRL (OMAP2_CONTROL_GENERAL + 0x032C)
>
> +/* 36xx-only CONTROL_GENERAL register offsets */
> +#define OMAP36XX_CONTROL_PROG_IO2 (OMAP2_CONTROL_GENERAL + 0x0198)
> +
> /* 34xx PADCONF register offsets */
> #define OMAP343X_PADCONF_ETK(i) (OMAP2_CONTROL_PADCONFS + 0x5a8
> + \
> (i)*2)
> @@ -200,6 +203,9 @@
> #define OMAP343X_CONTROL_WKUP_DEBOBS3 (OMAP343X_CONTROL_GENERAL_WKUP +
> 0x014)
> #define OMAP343X_CONTROL_WKUP_DEBOBS4 (OMAP343X_CONTROL_GENERAL_WKUP +
> 0x018)
>
> +/* 36xx-only GENERAL_WKUP register offsets */
> +#define OMAP36XX_CONTROL_PROG_IO_WKUP1 (OMAP343X_CONTROL_GENERAL_WKUP +
> 0x020)
> +
> /* 34xx D2D idle-related pins, handled by PM core */
> #define OMAP3_PADCONF_SAD2D_MSTANDBY 0x250
> #define OMAP3_PADCONF_SAD2D_IDLEACK 0x254
> @@ -250,6 +256,8 @@
> #define OMAP2_PBIASLITEVMODE0 (1 << 0)
>
> /* CONTROL_PROG_IO1 bits */
> +#define OMAP3630_PRG_I2C2_PULLUPRESX (1 << 0)
> +#define OMAP3630_PRG_I2C1_PULLUPRESX (1 << 19)
> #define OMAP3630_PRG_SDMMC1_SPEEDCTRL (1 << 20)
>
> /* CONTROL_IVA2_BOOTMOD bits */
> @@ -257,6 +265,12 @@
> #define OMAP3_IVA2_BOOTMOD_MASK (0xf << 0)
> #define OMAP3_IVA2_BOOTMOD_IDLE (0x1 << 0)
>
> +/* CONTROL_PROG_IO2 bits on omap3630 */
> +#define OMAP3630_PRG_I2C3_PULLUPRESX (1 << 7)
> +
> +/* CONTROL_PROG_IO_WKUP1 bits on omap3630 */
> +#define OMAP3630_PRG_SR_PULLUPRESX (1 << 5)
> +
> /* CONTROL_PADCONF_X bits */
> #define OMAP3_PADCONF_WAKEUPEVENT0 (1 << 15)
> #define OMAP3_PADCONF_WAKEUPENABLE0 (1 << 14)
> --
> 1.5.6.3
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
