Hello Allen,
a few comments:
On Thu, 21 Jan 2010, Pais, Allen wrote:
> >From 9a6b34dca3ff8ce4a200df4b65037978e4325452 Mon Sep 17 00:00:00 2001
> From: Allen Pais
> Date: Thu, 21 Jan 2010 21:23:41 +0530
> Subject: [PATCH 2/2] omap: 3630: Disable internal pull-ups
Please don't repeat the headers in the message - this will force the
maintainer to edit the commit message. The only header that should be
repeated is 'From:', in the event that you are forwarding along a patch
written by someone else.
Speaking of which, regarding Vikram's message, if these two patches were
written by Moiz, then they should say: "From: Moiz Sonasath
" at the beginning of the message.
Also:
> This patch disables the newly introduced internal pull-up feature in
> OMAP3630, to use only the external HW resistor >=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 resistor, 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 1.6K Ohm (recomended) or atleast 470 Ohm or greater for
> assured performance in HS mode.
>
> Signed-off-by: Moiz Sonasath
> Signed-off-by: Allen Pais
> ---
> arch/arm/mach-omap2/board-zoom-peripherals.c | 20
> arch/arm/plat-omap/include/plat/control.h| 13 +
> 2 files changed, 33 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/board-zoom-peripherals.c
> b/arch/arm/mach-omap2/board-zoom-peripherals.c
> index 5c8474c..3ddd51a 100755
> --- a/arch/arm/mach-omap2/board-zoom-peripherals.c
> +++ b/arch/arm/mach-omap2/board-zoom-peripherals.c
> @@ -257,6 +257,26 @@ static struct i2c_board_info __initdata
> zoom_i2c_boardinfo[] = {
>
> static int __init omap_i2c_init(void)
> {
> + /* Disable OMAP 3630 internal pull-ups for I2Ci */
> + if (cpu_is_omap3630()) {
> + 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 |= OMAP_3630_PRG_SR_PULLUPRESX;
> + omap_ctrl_writel(prog_io, OMAP36XX_CONTROL_PROG_IO_WKUP1);
> + }
> omap_register_i2c_bus(1, 2400, zoom_i2c_boardinfo,
> ARRAY_SIZE(zoom_i2c_boardinfo));
> omap_register_i2c_bus(2, 400, NULL, 0);
> diff --git a/arch/arm/plat-omap/include/plat/control.h
> b/arch/arm/plat-omap/include/plat/control.h
> index a745d62..2213d4b 100644
> --- a/arch/arm/plat-omap/include/plat/control.h
> +++ b/arch/arm/plat-omap/include/plat/control.h
> @@ -160,6 +160,8 @@
> #define OMAP343X_CONTROL_SRAMLDO5(OMAP2_CONTROL_GENERAL + 0x02C0)
> #define OMAP343X_CONTROL_CSI (OMAP2_CONTROL_GENERAL + 0x02C4)
>
> +/* 36xx-only CONTROL_GENERAL registor offsets */
> +#define OMAP36XX_CONTROL_PROG_IO2(OMAP2_CONTROL_GENERAL + 0x0198)
>
> /* 34xx PADCONF register offsets */
> #define OMAP343X_PADCONF_ETK(i) (OMAP2_CONTROL_PADCONFS + 0x5a8
> + \
> @@ -192,6 +194,9 @@
> #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 OMAP_36XX_CONTROL_PROG_IO_WKUP1 (OMAP343X_CONTROL_GENERAL_WKUP
> + 0x020)
Please remove the extra underscore after "OMAP" in the line above to
conform to the style of the rest of the file.
- Paul
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