From 44ac5e91580b9c88212bd0336214ac204e6e9fe7 Mon Sep 17 00:00:00 2001 From: Ben Wolsieffer Date: Thu, 28 Sep 2023 09:56:44 -0400 Subject: mmc: mmci: use peripheral flow control for STM32 The STM32 SDMMC peripheral (at least for the STM32F429, STM32F469 and STM32F746, which are all the currently supported devices using periphid 0x00880180) requires DMA to be performed in peripheral flow controller mode. From the STM32F74/5 reference manual, section 35.3.2: "SDMMC host allows only to use the DMA in peripheral flow controller mode. DMA stream used to serve SDMMC must be configured in peripheral flow controller mode" This patch adds a variant option to control peripheral flow control and enables it for the STM32 variant. Signed-off-by: Ben Wolsieffer Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20230928135644.1489691-1-ben.wolsieffer@hefring.com Signed-off-by: Ulf Hansson --- drivers/mmc/host/mmci.c | 3 ++- drivers/mmc/host/mmci.h | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index dda756a56379..e967cca7a16f 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -249,6 +249,7 @@ static struct variant_data variant_stm32 = { .f_max = 48000000, .pwrreg_clkgate = true, .pwrreg_nopower = true, + .dma_flow_controller = true, .init = mmci_variant_init, }; @@ -1015,7 +1016,7 @@ static int _mmci_dmae_prep_data(struct mmci_host *host, struct mmc_data *data, .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, .src_maxburst = variant->fifohalfsize >> 2, /* # of words */ .dst_maxburst = variant->fifohalfsize >> 2, /* # of words */ - .device_fc = false, + .device_fc = variant->dma_flow_controller, }; struct dma_chan *chan; struct dma_device *device; diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index 253197f132fc..34d9897c289b 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h @@ -332,6 +332,7 @@ enum mmci_busy_state { * @opendrain: bitmask identifying the OPENDRAIN bit inside MMCIPOWER register * @dma_lli: true if variant has dma link list feature. * @stm32_idmabsize_mask: stm32 sdmmc idma buffer size. + * @dma_flow_controller: use peripheral as flow controller for DMA. */ struct variant_data { unsigned int clkreg; @@ -378,6 +379,7 @@ struct variant_data { u8 dma_lli:1; u32 stm32_idmabsize_mask; u32 stm32_idmabsize_align; + bool dma_flow_controller; void (*init)(struct mmci_host *host); }; -- cgit v1.2.3