[PATCH 07/15] dmaengine: dw: revisit data_width property
Andy Shevchenko
andriy.shevchenko at linux.intel.com
Mon Jan 25 00:42:21 PST 2016
On Sun, 2016-01-24 at 19:21 +0000, Mans Rullgard wrote:
> From: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
>
> There are several changes are done here:
>
> - Convert the property to be in bytes
>
> Much more convenient than keeping encoded value.
>
> - Use one value for all AHB masters for now
>
> It seems in practice we have no controllers where masters have
> different
> data bus width, we still might return to distinct values when
> there is a use
> case.
>
> - Rename data_width to data-width in the device tree bindings.
>
> - While here, replace dwc_fast_ffs() by __ffs().
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
> Signed-off-by: Mans Rullgard <mans at mansr.com>
> ---
> This patch changes the DT binding, so it should probably be amended
> for
> compatibility with old device trees. I've included it as is since I
> think
> the change as such is good.
So, since all users have at least one master defined, we may easily to
use similar line for old DT variable
if (!of_property_read_u32(np, "data_width", &tmp)) /* removeme: old */
pdata->data_width = tmp;
else if (!of_property_read_u32(np, "data-
width", &tmp)) /* removeme: new */
pdata->data_width = tmp;
I any case Viresh might comment on this since it was his code regarding
to support SPEAr SoCs.
> ---
> Documentation/devicetree/bindings/dma/snps-dma.txt | 5 ++-
> arch/arc/boot/dts/abilis_tb10x.dtsi | 2 +-
> arch/arm/boot/dts/spear13xx.dtsi | 4 +--
> drivers/dma/dw/core.c | 40 +++---------
> ----------
> drivers/dma/dw/platform.c | 8 ++---
> drivers/dma/dw/regs.h | 2 +-
> include/linux/platform_data/dma-dw.h | 5 ++-
> 7 files changed, 16 insertions(+), 50 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt
> b/Documentation/devicetree/bindings/dma/snps-dma.txt
> index c99c1ffac199..fe7f7710a6b4 100644
> --- a/Documentation/devicetree/bindings/dma/snps-dma.txt
> +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt
> @@ -13,8 +13,7 @@ Required properties:
> - chan_priority: priority of channels. 0 (default): increase from
> chan 0->n, 1:
> increase from chan n->0
> - block_size: Maximum block size supported by the controller
> -- data_width: Maximum data width supported by hardware per AHB
> master
> - (0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
> +- data-width: Maximum data width supported by hardware (in bytes)
>
>
> Optional properties:
> @@ -38,7 +37,7 @@ Example:
> chan_allocation_order = <1>;
> chan_priority = <1>;
> block_size = <0xfff>;
> - data_width = <3 3>;
> + data-width = <8>;
> };
>
> DMA clients connected to the Designware DMA controller must use the
> format
> diff --git a/arch/arc/boot/dts/abilis_tb10x.dtsi
> b/arch/arc/boot/dts/abilis_tb10x.dtsi
> index cfb5052239a1..2f53bedb0cde 100644
> --- a/arch/arc/boot/dts/abilis_tb10x.dtsi
> +++ b/arch/arc/boot/dts/abilis_tb10x.dtsi
> @@ -112,7 +112,7 @@
> chan_allocation_order = <0>;
> chan_priority = <1>;
> block_size = <0x7ff>;
> - data_width = <2>;
> + data-width = <4>;
> clocks = <&ahb_clk>;
> clock-names = "hclk";
> };
> diff --git a/arch/arm/boot/dts/spear13xx.dtsi
> b/arch/arm/boot/dts/spear13xx.dtsi
> index 14594ce8c18a..474b66fa6a32 100644
> --- a/arch/arm/boot/dts/spear13xx.dtsi
> +++ b/arch/arm/boot/dts/spear13xx.dtsi
> @@ -117,7 +117,7 @@
> chan_priority = <1>;
> block_size = <0xfff>;
> dma-masters = <2>;
> - data_width = <3 3>;
> + data-width = <8>;
> };
>
> dma at eb000000 {
> @@ -133,7 +133,7 @@
> chan_allocation_order = <1>;
> chan_priority = <1>;
> block_size = <0xfff>;
> - data_width = <3 3>;
> + data-width = <8>;
> };
>
> fsmc: flash at b0000000 {
> diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
> index 140ea59ec882..28278e4c77ad 100644
> --- a/drivers/dma/dw/core.c
> +++ b/drivers/dma/dw/core.c
> @@ -168,21 +168,6 @@ static void dwc_initialize(struct dw_dma_chan
> *dwc)
>
> /*----------------------------------------------------------------
> ------*/
>
> -static inline unsigned int dwc_fast_ffs(unsigned long long v)
> -{
> - /*
> - * We can be a lot more clever here, but this should take
> care
> - * of the most common optimization.
> - */
> - if (!(v & 7))
> - return 3;
> - else if (!(v & 3))
> - return 2;
> - else if (!(v & 1))
> - return 1;
> - return 0;
> -}
> -
> static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
> {
> dev_err(chan2dev(&dwc->chan),
> @@ -712,7 +697,6 @@ dwc_prep_dma_memcpy(struct dma_chan *chan,
> dma_addr_t dest, dma_addr_t src,
> size_t offset;
> unsigned int src_width;
> unsigned int dst_width;
> - unsigned int data_width;
> u32 ctllo;
>
> dev_vdbg(chan2dev(chan),
> @@ -726,10 +710,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan,
> dma_addr_t dest, dma_addr_t src,
>
> dwc->direction = DMA_MEM_TO_MEM;
>
> - data_width = dw->data_width[dwc->m_master];
> -
> - src_width = dst_width = min_t(unsigned int, data_width,
> - dwc_fast_ffs(src | dest |
> len));
> + src_width = dst_width = __ffs(dw->data_width | src | dest |
> len);
>
> ctllo = DWC_DEFAULT_CTLLO(chan)
> | DWC_CTLL_DST_WIDTH(dst_width)
> @@ -792,7 +773,6 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct
> scatterlist *sgl,
> dma_addr_t reg;
> unsigned int reg_width;
> unsigned int mem_width;
> - unsigned int data_width;
> unsigned int i;
> struct scatterlist *sg;
> size_t total_len = 0;
> @@ -818,8 +798,6 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct
> scatterlist *sgl,
> ctllo |= sconfig->device_fc ?
> DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
> DWC_CTLL_FC(DW_DMA_FC_D_M2P);
>
> - data_width = dw->data_width[dwc->m_master];
> -
> for_each_sg(sgl, sg, sg_len, i) {
> struct dw_desc *desc;
> u32 len, dlen, mem;
> @@ -827,8 +805,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct
> scatterlist *sgl,
> mem = sg_dma_address(sg);
> len = sg_dma_len(sg);
>
> - mem_width = min_t(unsigned int,
> - data_width,
> dwc_fast_ffs(mem | len));
> + mem_width = __ffs(dw->data_width | mem |
> len);
>
> slave_sg_todev_fill_desc:
> desc = dwc_desc_get(dwc);
> @@ -874,8 +851,6 @@ slave_sg_todev_fill_desc:
> ctllo |= sconfig->device_fc ?
> DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
> DWC_CTLL_FC(DW_DMA_FC_D_P2M);
>
> - data_width = dw->data_width[dwc->m_master];
> -
> for_each_sg(sgl, sg, sg_len, i) {
> struct dw_desc *desc;
> u32 len, dlen, mem;
> @@ -883,8 +858,7 @@ slave_sg_todev_fill_desc:
> mem = sg_dma_address(sg);
> len = sg_dma_len(sg);
>
> - mem_width = min_t(unsigned int,
> - data_width,
> dwc_fast_ffs(mem | len));
> + mem_width = __ffs(dw->data_width | mem |
> len);
>
> slave_sg_fromdev_fill_desc:
> desc = dwc_desc_get(dwc);
> @@ -1531,10 +1505,7 @@ int dw_dma_probe(struct dw_dma_chip *chip,
> struct dw_dma_platform_data *pdata)
> /* Get hardware configuration parameters */
> pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN
> & 7) + 1;
> pdata->nr_masters = (dw_params >>
> DW_PARAMS_NR_MASTER & 3) + 1;
> - for (i = 0; i < pdata->nr_masters; i++) {
> - pdata->data_width[i] =
> - (dw_params >>
> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
> - }
> + pdata->data_width = 4 << (dw_params >>
> DW_PARAMS_DATA_WIDTH(0) & 3);
> max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
>
> /* Fill platform data with the default values */
> @@ -1556,8 +1527,7 @@ int dw_dma_probe(struct dw_dma_chip *chip,
> struct dw_dma_platform_data *pdata)
>
> /* Get hardware configuration parameters */
> dw->nr_masters = pdata->nr_masters;
> - for (i = 0; i < dw->nr_masters; i++)
> - dw->data_width[i] = pdata->data_width[i];
> + dw->data_width = pdata->data_width;
>
> /* Calculate all channel mask before DMA setup */
> dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
> diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
> index d3e1abcebd7f..89d0461f5dcc 100644
> --- a/drivers/dma/dw/platform.c
> +++ b/drivers/dma/dw/platform.c
> @@ -102,8 +102,8 @@ dw_dma_parse_dt(struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> struct dw_dma_platform_data *pdata;
> - u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
> u32 nr_channels;
> + u32 tmp;
>
> if (!np) {
> dev_err(&pdev->dev, "Missing DT data\n");
> @@ -138,10 +138,8 @@ dw_dma_parse_dt(struct platform_device *pdev)
> pdata->nr_masters = tmp;
> }
>
> - if (!of_property_read_u32_array(np, "data_width", arr,
> - pdata->nr_masters))
> - for (tmp = 0; tmp < pdata->nr_masters; tmp++)
> - pdata->data_width[tmp] = arr[tmp];
> + if (!of_property_read_u32(np, "data-width", &tmp))
> + pdata->data_width = tmp;
>
> return pdata;
> }
> diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
> index e4b277565165..87bc97fca084 100644
> --- a/drivers/dma/dw/regs.h
> +++ b/drivers/dma/dw/regs.h
> @@ -285,7 +285,7 @@ struct dw_dma {
>
> /* hardware configuration */
> unsigned char nr_masters;
> - unsigned char data_width[DW_DMA_MAX_NR_MASTER
> S];
> + unsigned char data_width;
> };
>
> static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma
> *dw)
> diff --git a/include/linux/platform_data/dma-dw.h
> b/include/linux/platform_data/dma-dw.h
> index b881b978e486..4120a3eb71ca 100644
> --- a/include/linux/platform_data/dma-dw.h
> +++ b/include/linux/platform_data/dma-dw.h
> @@ -42,8 +42,7 @@ struct dw_dma_slave {
> * @chan_priority: Set channel priority increasing from 0 to 7 or 7
> to 0.
> * @block_size: Maximum block size supported by the controller
> * @nr_masters: Number of AHB masters supported by the controller
> - * @data_width: Maximum data width supported by hardware per AHB
> master
> - * (0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
> + * @data_width: Maximum data width supported by hardware (in bytes)
> */
> struct dw_dma_platform_data {
> unsigned int nr_channels;
> @@ -57,7 +56,7 @@ struct dw_dma_platform_data {
> unsigned char chan_priority;
> unsigned short block_size;
> unsigned char nr_masters;
> - unsigned char data_width[DW_DMA_MAX_NR_MASTERS];
> + unsigned char data_width;
> };
>
> #endif /* _PLATFORM_DATA_DMA_DW_H */
--
Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Intel Finland Oy
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