[RFC PATCH 2/3] dmaengine: add peripheral configuration

From: Vinod Koul
Date: Mon Aug 24 2020 - 05:37:59 EST


Some complex dmaengine controllers have capability to program the
peripheral device, so pass on the peripheral configuration as part of
dma_slave_config

Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
---
include/linux/dmaengine.h | 75 +++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 6fbd5c99e30c..264643ca9209 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -380,6 +380,73 @@ enum dma_slave_buswidth {
DMA_SLAVE_BUSWIDTH_64_BYTES = 64,
};

+/**
+ * enum spi_transfer_cmd - spi transfer commands
+ */
+enum spi_transfer_cmd {
+ SPI_TX = 1,
+ SPI_RX,
+ SPI_DUPLEX,
+};
+
+/**
+ * struct dmaengine_spi_config - spi config for peripheral
+ *
+ * @loopback_en: spi loopback enable when set
+ * @clock_pol: clock polarity
+ * @data_pol: data polarity
+ * @pack_en: process tx/rx buffers as packed
+ * @word_len: spi word length
+ * @clk_div: source clock divider
+ * @clk_src: serial clock
+ * @cmd: spi cmd
+ * @cs: chip select toggle
+ * @rx_len: receive length for spi buffer
+ */
+struct dmaengine_spi_config {
+ u8 loopback_en;
+ u8 clock_pol;
+ u8 data_pol;
+ u8 pack_en;
+ u8 word_len;
+ u32 clk_div;
+ u32 clk_src;
+ u8 fragmentation;
+ enum spi_transfer_cmd cmd;
+ u8 cs;
+ u32 rx_len;
+};
+
+/**
+ * struct dmaengine_i2c_config - i2c config for peripheral
+ *
+ * @pack_enable: process tx/rx buffers as packed
+ * @cycle_count: clock cycles to be sent
+ * @high_count: high period of clock
+ * @low_count: low period of clock
+ * @clk_div: source clock divider
+ * @addr: i2c bus address
+ * @strech: strech the clock at eot
+ * @op: i2c cmd
+ */
+struct dmaengine_i2c_config {
+ u8 pack_enable;
+ u8 cycle_count;
+ u8 high_count;
+ u8 low_count;
+ u16 clk_div;
+ u8 addr;
+ u8 strech;
+ u8 op;
+};
+
+enum dmaengine_peripheral {
+ DMAENGINE_PERIPHERAL_SPI,
+ DMAENGINE_PERIPHERAL_I2C,
+ DMAENGINE_PERIPHERAL_UART,
+ DMAENGINE_PERIPHERAL_LAST = DMAENGINE_PERIPHERAL_UART,
+};
+
/**
* struct dma_slave_config - dma slave channel runtime config
* @direction: whether the data shall go in or out on this slave
@@ -418,6 +485,10 @@ enum dma_slave_buswidth {
* @slave_id: Slave requester id. Only valid for slave channels. The dma
* slave peripheral will have unique id as dma requester which need to be
* pass as slave config.
+ * @peripheral: type of peripheral to DMA to/from
+ * @set_config: set peripheral config
+ * @spi: peripheral config for spi
+ * @:i2c peripheral config for i2c
*
* This struct is passed in as configuration data to a DMA engine
* in order to set up a certain channel for DMA transport at runtime.
@@ -443,6 +514,10 @@ struct dma_slave_config {
u32 dst_port_window_size;
bool device_fc;
unsigned int slave_id;
+ enum dmaengine_peripheral peripheral;
+ u8 set_config;
+ struct dmaengine_spi_config spi;
+ struct dmaengine_i2c_config i2c;
};

/**
--
2.26.2