Messages in this thread Patch in this message | | | Date | Tue, 2 Jul 2013 17:46:06 +0200 (CEST) | From | Guennadi Liakhovetski <> | Subject | [PATCH 3/3] DMA: shdma: support the new CHCLR register layout |
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On newer r-car SoCs the CHCLR register only contains one bit per channel, to which a 1 has to be written to reset the channel. Older SoC versions had one CHCLR register per channel, to which a 0 must be written to reset the channel and clear its buffers. This patch adds support for the newer layout.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> --- drivers/dma/sh/shdma.c | 6 ++++-- include/linux/sh_dma.h | 12 +++++++++++- 2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c index 64eb7fb..883a4de 100644 --- a/drivers/dma/sh/shdma.c +++ b/drivers/dma/sh/shdma.c @@ -54,9 +54,11 @@ static LIST_HEAD(sh_dmae_devices); static void channel_clear(struct sh_dmae_chan *sh_dc) { struct sh_dmae_device *shdev = to_sh_dev(sh_dc); + const struct sh_dmae_channel *chan_pdata = shdev->pdata->channel + + sh_dc->shdma_chan.id; + u32 val = chan_pdata->chclr_bit < 0 ? 0 : 1 << chan_pdata->chclr_bit; - __raw_writel(0, shdev->chan_reg + - shdev->pdata->channel[sh_dc->shdma_chan.id].chclr_offset); + __raw_writel(val, shdev->chan_reg + chan_pdata->chclr_offset); } static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg) diff --git a/include/linux/sh_dma.h b/include/linux/sh_dma.h index 4e83f3e..9316a1d 100644 --- a/include/linux/sh_dma.h +++ b/include/linux/sh_dma.h @@ -33,11 +33,21 @@ struct sh_dmae_slave_config { char mid_rid; }; +/** + * struct sh_dmae_channel - DMAC channel platform data + * @offset: register offset within the main IOMEM resource + * @dmars: channel DMARS register offset + * @chclr_offset: channel CHCLR register offset + * @dmars_bit: channel DMARS field offset within the register + * @chclr_bit: > 0: bit position, to be set to reset the channel + * < 0: CHCLR has to be cleared to clear channel's buffers + */ struct sh_dmae_channel { unsigned int offset; unsigned int dmars; - unsigned int dmars_bit; unsigned int chclr_offset; + unsigned char dmars_bit; + signed char chclr_bit; }; struct sh_dmae_pdata { -- 1.7.2.5
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