[PATCH v1] dmaengine: stm32_mdma: activate pack/unpack feature
Benjamin Gaignard
benjamin.gaignard at linaro.org
Tue Oct 17 07:26:50 PDT 2017
+Arnd since it should also fix 64 bits division issue
2017-10-17 15:43 GMT+02:00 Pierre-Yves MORDRET <pierre-yves.mordret at st.com>:
> If source and destination bus width differs pack/unpack MDMA
> feature has to be activated for alignment.
> This pack/unpack feature implies to have both source/destination address
> and buffer length aligned on bus width.
>
> Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret at st.com>
> ---
> drivers/dma/stm32-mdma.c | 84 ++++++++++++++++++++++++++++--------------------
> 1 file changed, 50 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
> index d3be6bf..daa1602 100644
> --- a/drivers/dma/stm32-mdma.c
> +++ b/drivers/dma/stm32-mdma.c
> @@ -387,14 +387,20 @@ static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
> }
> }
>
> -static enum dma_slave_buswidth stm32_mdma_get_max_width(u32 buf_len, u32 tlen)
> +static enum dma_slave_buswidth stm32_mdma_get_max_width(dma_addr_t addr,
> + u32 buf_len, u32 tlen)
> {
> enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
>
> for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
> max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
> max_width >>= 1) {
> - if (((buf_len % max_width) == 0) && (tlen >= max_width))
> + /*
> + * Address and buffer length both have to be aligned on
> + * bus width
> + */
> + if ((((buf_len | addr) & (max_width - 1)) == 0) &&
> + tlen >= max_width)
> break;
> }
>
> @@ -486,7 +492,8 @@ static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
> static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> enum dma_transfer_direction direction,
> u32 *mdma_ccr, u32 *mdma_ctcr,
> - u32 *mdma_ctbr, u32 buf_len)
> + u32 *mdma_ctbr, dma_addr_t addr,
> + u32 buf_len)
> {
> struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
> struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
> @@ -520,6 +527,9 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
> ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
>
> + /* Disable Pack Enable */
> + ctcr &= ~STM32_MDMA_CTCR_PKE;
> +
> /* Check burst size constraints */
> if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
> dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
> @@ -551,6 +561,8 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
>
> switch (direction) {
> case DMA_MEM_TO_DEV:
> + dst_addr = chan->dma_config.dst_addr;
> +
> /* Set device data size */
> dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
> if (dst_bus_width < 0)
> @@ -567,7 +579,7 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
>
> /* Set memory data size */
> - src_addr_width = stm32_mdma_get_max_width(buf_len, tlen);
> + src_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
> chan->mem_width = src_addr_width;
> src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
> if (src_bus_width < 0)
> @@ -587,15 +599,19 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
>
> /* Select bus */
> - dst_addr = chan->dma_config.dst_addr;
> stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
> dst_addr);
>
> + if (dst_bus_width != src_bus_width)
> + ctcr |= STM32_MDMA_CTCR_PKE;
> +
> /* Set destination address */
> stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
> break;
>
> case DMA_DEV_TO_MEM:
> + src_addr = chan->dma_config.src_addr;
> +
> /* Set device data size */
> src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
> if (src_bus_width < 0)
> @@ -611,7 +627,7 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
>
> /* Set memory data size */
> - dst_addr_width = stm32_mdma_get_max_width(buf_len, tlen);
> + dst_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
> chan->mem_width = dst_addr_width;
> dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
> if (dst_bus_width < 0)
> @@ -630,10 +646,12 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
>
> /* Select bus */
> - src_addr = chan->dma_config.src_addr;
> stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
> src_addr);
>
> + if (dst_bus_width != src_bus_width)
> + ctcr |= STM32_MDMA_CTCR_PKE;
> +
> /* Set source address */
> stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
> break;
> @@ -719,23 +737,27 @@ static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
> return -EINVAL;
> }
>
> - ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
> - &ctbr, sg_dma_len(sg));
> - if (ret < 0)
> - return ret;
> -
> if (direction == DMA_MEM_TO_DEV) {
> src_addr = sg_dma_address(sg);
> dst_addr = dma_config->dst_addr;
> + ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
> + &ctcr, &ctbr, src_addr,
> + sg_dma_len(sg));
> stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
> src_addr);
> } else {
> src_addr = dma_config->src_addr;
> dst_addr = sg_dma_address(sg);
> + ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
> + &ctcr, &ctbr, dst_addr,
> + sg_dma_len(sg));
> stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
> dst_addr);
> }
>
> + if (ret < 0)
> + return ret;
> +
> stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
> dst_addr, sg_dma_len(sg), ctcr, ctbr,
> i == sg_len - 1, i == 0, false);
> @@ -830,27 +852,29 @@ stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
> if (!desc)
> return NULL;
>
> - ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr, &ctbr,
> - period_len);
> - if (ret < 0)
> - goto xfer_setup_err;
> -
> - /* Enable interrupts */
> - ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
> - ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
> - desc->ccr = ccr;
> -
> /* Select bus */
> if (direction == DMA_MEM_TO_DEV) {
> src_addr = buf_addr;
> + ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
> + &ctbr, src_addr, period_len);
> stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
> src_addr);
> } else {
> dst_addr = buf_addr;
> + ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
> + &ctbr, dst_addr, period_len);
> stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
> dst_addr);
> }
>
> + if (ret < 0)
> + goto xfer_setup_err;
> +
> + /* Enable interrupts */
> + ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
> + ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
> + desc->ccr = ccr;
> +
> /* Configure hwdesc list */
> for (i = 0; i < count; i++) {
> if (direction == DMA_MEM_TO_DEV) {
> @@ -956,9 +980,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
>
> /* Set source best burst size */
> - max_width = stm32_mdma_get_max_width(len, tlen);
> - if (src % max_width)
> - max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> + max_width = stm32_mdma_get_max_width(src, len, tlen);
> src_bus_width = stm32_mdma_get_width(chan, max_width);
>
> max_burst = tlen / max_width;
> @@ -971,9 +993,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> STM32_MDMA_CTCR_SINCOS(src_bus_width);
>
> /* Set destination best burst size */
> - max_width = stm32_mdma_get_max_width(len, tlen);
> - if (dest % max_width)
> - max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> + max_width = stm32_mdma_get_max_width(dest, len, tlen);
> dst_bus_width = stm32_mdma_get_width(chan, max_width);
>
> max_burst = tlen / max_width;
> @@ -1014,9 +1034,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> STM32_MDMA_MAX_BLOCK_LEN);
>
> /* Set source best burst size */
> - max_width = stm32_mdma_get_max_width(len, tlen);
> - if (src % max_width)
> - max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> + max_width = stm32_mdma_get_max_width(src, len, tlen);
> src_bus_width = stm32_mdma_get_width(chan, max_width);
>
> max_burst = tlen / max_width;
> @@ -1030,9 +1048,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> STM32_MDMA_CTCR_SINCOS(src_bus_width);
>
> /* Set destination best burst size */
> - max_width = stm32_mdma_get_max_width(len, tlen);
> - if (dest % max_width)
> - max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> + max_width = stm32_mdma_get_max_width(dest, len, tlen);
> dst_bus_width = stm32_mdma_get_width(chan, max_width);
>
> max_burst = tlen / max_width;
> --
> 2.7.4
>
>
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--
Benjamin Gaignard
Graphic Study Group
Linaro.org │ Open source software for ARM SoCs
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