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

From: Vinod Koul <vkoul@kernel.org>
To: dmaengine@vger.kernel.org
Cc: Vinod Koul <vkoul@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [RFC PATCH 2/3] dmaengine: add peripheral configuration
Date: Mon, 24 Aug 2020 14:17:11 +0530	[thread overview]
Message-ID: <20200824084712.2526079-3-vkoul@kernel.org> (raw)
In-Reply-To: <20200824084712.2526079-1-vkoul@kernel.org>

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@kernel.org>
---
 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

