i2s regmap and dma setup

Author: 54shady

debug/codec/rk_i2s.c

@@ -10,14 +10,39 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+#include <sound/dmaengine_pcm.h>
+
 #define I2S_DEFAULT_FREQ	(11289600)
+#define I2S_DMA_BURST_SIZE	(16) /* size * width: 16*4 = 64 bytes */
+
+/* I2S regname and offset */
+#define I2S_TXCR	(0x0000)
+#define I2S_RXCR	(0x0004)
+#define I2S_CKR		(0x0008)
+#define I2S_FIFOLR	(0x000c)
+#define I2S_DMACR	(0x0010)
+#define I2S_INTCR	(0x0014)
+#define I2S_INTSR	(0x0018)
+#define I2S_XFER	(0x001c)
+#define I2S_CLR		(0x0020)
+#define I2S_TXDR	(0x0024)
+#define I2S_RXDR	(0x0028)
 
 /* 描述I2S控制器的数据结构 */
 struct rk_i2s_dev {
 	struct device *dev;
 	struct clk *clk; /* bclk */
 	struct clk *mclk; /*mclk output only */
 	struct clk *hclk; /*ahb clk */
+
+	struct snd_dmaengine_dai_dma_data capture_dma_data;
+	struct snd_dmaengine_dai_dma_data playback_dma_data;
+
+	struct regmap *regmap;
+
+	/* 发送和接收数据的标志 */
+	bool tx_start;
+	bool rx_start;
 };
 
 static const struct of_device_id rockchip_i2s_match[] = {
@@ -76,6 +101,83 @@ void enable_clks(struct rk_i2s_dev *i2s)
 	clk_prepare_enable(i2s->mclk);
 }
 
+/* 可写寄存器 */
+static bool rockchip_i2s_wr_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+		case I2S_TXCR:
+		case I2S_RXCR:
+		case I2S_CKR:
+		case I2S_DMACR:
+		case I2S_INTCR:
+		case I2S_XFER:
+		case I2S_CLR:
+		case I2S_TXDR:
+			return true;
+		default:
+			return false;
+	}
+}
+
+/* 可读寄存器 */
+static bool rockchip_i2s_rd_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+		case I2S_TXCR:
+		case I2S_RXCR:
+		case I2S_CKR:
+		case I2S_DMACR:
+		case I2S_INTCR:
+		case I2S_XFER:
+		case I2S_CLR:
+		case I2S_RXDR:
+		case I2S_FIFOLR:
+		case I2S_INTSR:
+			return true;
+		default:
+			return false;
+	}
+}
+
+/* VOLATILE 寄存器 */
+static bool rockchip_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+		case I2S_INTSR:
+		case I2S_CLR:
+			return true;
+		default:
+			return false;
+	}
+}
+
+/* 私有寄存器 */
+static bool rockchip_i2s_precious_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+		default:
+			return false;
+	}
+}
+
+/*
+ * 从芯片手册可以得到下面信息
+ * I2S控制器的寄存器是32位的
+ * 每个寄存器步进大小为4
+ * 用32位的值来表示
+ */
+static const struct regmap_config rockchip_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = I2S_RXDR,
+	.writeable_reg = rockchip_i2s_wr_reg,
+	.readable_reg = rockchip_i2s_rd_reg,
+	.volatile_reg = rockchip_i2s_volatile_reg,
+	.precious_reg = rockchip_i2s_precious_reg,
+	.cache_type = REGCACHE_FLAT,
+};
+
 static int rockchip_i2s_probe(struct platform_device *pdev)
 {
 	struct rk_i2s_dev *i2s;
@@ -110,6 +212,37 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
 		goto EXIT;
 	}
 
+	/* regmap setup */
+	i2s->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
+			&rockchip_i2s_regmap_config);
+	if (IS_ERR(i2s->regmap)) {
+		dev_err(&pdev->dev,
+				"Failed to initialise managed register map\n");
+		ret = PTR_ERR(i2s->regmap);
+		goto EXIT;
+	}
+
+	/*
+	 * DMA setup for playback and capture
+	 * playback --> i2s tx fifo
+	 * capture --> i2s rx fifo
+	 */
+	i2s->playback_dma_data.addr = res->start + I2S_TXDR;
+	i2s->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	i2s->playback_dma_data.maxburst = I2S_DMA_BURST_SIZE;
+
+	i2s->capture_dma_data.addr = res->start + I2S_RXDR;
+	i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	i2s->capture_dma_data.maxburst = I2S_DMA_BURST_SIZE;
+
+	/* turn off xfer and recv while init */
+	i2s->tx_start = false;
+	i2s->rx_start = false;
+
+	/* i2s setup */
+	i2s->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, i2s);
+
 	printk("%s, %d\n", __FUNCTION__, __LINE__);
 
 EXIT: