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Groups > linux.kernel > #1204884
| From | Daniel Kurtz <djkurtz@chromium.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init function |
| Date | 2015-08-11 10:40 +0200 |
| Message-ID | <pWdge-8dF-23@gated-at.bofh.it> (permalink) |
| References | <pUnMJ-1Zx-5@gated-at.bofh.it> <pUnMJ-1Zx-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Aug 6, 2015 at 3:22 PM, Eddie Huang <eddie.huang@mediatek.com> wrote:
> Reset DMA in hardware init function to avoid unknown hardware state
> before do any I2C operation.
>
> Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com>
> Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
> ---
> drivers/i2c/busses/i2c-mt65xx.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index 9920eef..e28ad4c 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -59,6 +59,7 @@
> #define I2C_DMA_START_EN 0x0001
> #define I2C_DMA_INT_FLAG_NONE 0x0000
> #define I2C_DMA_CLR_FLAG 0x0000
> +#define I2C_DMA_HARD_RST 0x0002
>
> #define I2C_DEFAULT_SPEED 100000 /* hz */
> #define MAX_FS_MODE_SPEED 400000
> @@ -81,6 +82,7 @@ enum DMA_REGS_OFFSET {
> OFFSET_INT_FLAG = 0x0,
> OFFSET_INT_EN = 0x04,
> OFFSET_EN = 0x08,
> + OFFSET_RST = 0x0c,
> OFFSET_CON = 0x18,
> OFFSET_TX_MEM_ADDR = 0x1c,
> OFFSET_RX_MEM_ADDR = 0x20,
> @@ -262,6 +264,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
> I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
> writew(control_reg, i2c->base + OFFSET_CONTROL);
> writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
> +
> + writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
> + udelay(50);
> + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
> }
>
> /*
> --
> 1.7.9.5
>
> --
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[PATCH v2 0/2] Mediatek I2C fixup Eddie Huang <eddie.huang@mediatek.com> - 2015-08-06 09:30 +0200
[PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Eddie Huang <eddie.huang@mediatek.com> - 2015-08-06 09:30 +0200
Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Daniel Kurtz <djkurtz@chromium.org> - 2015-08-11 10:40 +0200
Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Wolfram Sang <wsa@the-dreams.de> - 2015-08-11 17:00 +0200
Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Daniel Kurtz <djkurtz@chromium.org> - 2015-08-12 03:40 +0200
Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Wolfram Sang <wsa@the-dreams.de> - 2015-08-12 03:50 +0200
[PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init function Eddie Huang <eddie.huang@mediatek.com> - 2015-08-06 09:30 +0200
Re: [PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init function Daniel Kurtz <djkurtz@chromium.org> - 2015-08-11 10:40 +0200
Re: [PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init function Wolfram Sang <wsa@the-dreams.de> - 2015-08-11 17:00 +0200
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