spi: stm32-qspi: Set DMA maxburst dynamically

Set src_maxburst and dst_maxburst dynamically from DMA
capabilities.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://patch.msgid.link/20251208-upstream_qspi_ospi_updates-v2-5-62526c9467dc@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
index f2d19f1c5ab1c4ea4c2269108c7250fc00d707a9..c131441e4dd4af423fba63fc96587f955dd3b8e6 100644 (file)
--- a/drivers/spi/spi-stm32-qspi.c
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -689,6 +689,7 @@ static int stm32_qspi_dma_setup(struct stm32_qspi *qspi)
 {
        struct dma_slave_config dma_cfg;
        struct device *dev = qspi->dev;
+       struct dma_slave_caps caps;
        int ret = 0;
 
        memset(&dma_cfg, 0, sizeof(dma_cfg));
@@ -697,8 +698,6 @@ static int stm32_qspi_dma_setup(struct stm32_qspi *qspi)
        dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
        dma_cfg.src_addr = qspi->phys_base + QSPI_DR;
        dma_cfg.dst_addr = qspi->phys_base + QSPI_DR;
-       dma_cfg.src_maxburst = 4;
-       dma_cfg.dst_maxburst = 4;
 
        qspi->dma_chrx = dma_request_chan(dev, "rx");
        if (IS_ERR(qspi->dma_chrx)) {
@@ -707,6 +706,11 @@ static int stm32_qspi_dma_setup(struct stm32_qspi *qspi)
                if (ret == -EPROBE_DEFER)
                        goto out;
        } else {
+               ret = dma_get_slave_caps(qspi->dma_chrx, &caps);
+               if (ret)
+                       return ret;
+
+               dma_cfg.src_maxburst = caps.max_burst / dma_cfg.src_addr_width;
                if (dmaengine_slave_config(qspi->dma_chrx, &dma_cfg)) {
                        dev_err(dev, "dma rx config failed\n");
                        dma_release_channel(qspi->dma_chrx);
@@ -719,6 +723,11 @@ static int stm32_qspi_dma_setup(struct stm32_qspi *qspi)
                ret = PTR_ERR(qspi->dma_chtx);
                qspi->dma_chtx = NULL;
        } else {
+               ret = dma_get_slave_caps(qspi->dma_chtx, &caps);
+               if (ret)
+                       return ret;
+
+               dma_cfg.dst_maxburst = caps.max_burst / dma_cfg.dst_addr_width;
                if (dmaengine_slave_config(qspi->dma_chtx, &dma_cfg)) {
                        dev_err(dev, "dma tx config failed\n");
                        dma_release_channel(qspi->dma_chtx);