drm/sun4i: hdmi: Add support for controller hardware variants

The HDMI controller found in earlier Allwinner SoCs have slight
differences between the A10, A10s, and the A31:

  - Need different initial values for the PLL related registers

  - Different behavior of the DDC and TMDS clocks

  - Different register layout for the DDC portion

  - Separate DDC parent clock on the A31

  - Explicit reset control

For the A31, the HDMI TMDS clock has a different value offset for
the divider. The HDMI DDC block is different from the one in the
other SoCs. As far as the DDC clock goes, it has no pre-divider,
as it is clocked from a slower parent clock, not the TMDS clock.
The divider offset from the register value is different. And the
clock control register is at a different offset.

A new variant data structure is created to store pointers to the
above functions, structures, and the different initial values.
Another flag notates whether there is a separate DDC parent clock.
If not, the TMDS clock is passed to the DDC clock create function,
as before.

Regmap fields are used to deal with the different register layout
of the DDC block.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171010032008.682-8-wens@csie.org

1 files changed, 164 insertions, 63 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c
index 2e42d09ab42e..58e9d37e8c17 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c
@@ -25,8 +25,6 @@
 
 /* FIFO request bit is set when FIFO level is above RX_THRESHOLD during read */
 #define RX_THRESHOLD SUN4I_HDMI_DDC_FIFO_CTRL_RX_THRES_MAX
-/* FIFO request bit is set when FIFO level is below TX_THRESHOLD during write */
-#define TX_THRESHOLD 1
 
 static int fifo_transfer(struct sun4i_hdmi *hdmi, u8 *buf, int len, bool read)
 {
@@ -39,27 +37,36 @@ static int fifo_transfer(struct sun4i_hdmi *hdmi, u8 *buf, int len, bool read)
 			 SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST |
 			 SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE;
 	u32 reg;
+	/*
+	 * If threshold is inclusive, then the FIFO may only have
+	 * RX_THRESHOLD number of bytes, instead of RX_THRESHOLD + 1.
+	 */
+	int read_len = RX_THRESHOLD +
+		(hdmi->variant->ddc_fifo_thres_incl ? 0 : 1);
 
-	/* Limit transfer length by FIFO threshold */
-	len = min_t(int, len, read ? (RX_THRESHOLD + 1) :
-			      (SUN4I_HDMI_DDC_FIFO_SIZE - TX_THRESHOLD + 1));
+	/*
+	 * Limit transfer length by FIFO threshold or FIFO size.
+	 * For TX the threshold is for an empty FIFO.
+	 */
+	len = min_t(int, len, read ? read_len : SUN4I_HDMI_DDC_FIFO_SIZE);
 
 	/* Wait until error, FIFO request bit set or transfer complete */
-	if (readl_poll_timeout(hdmi->base + SUN4I_HDMI_DDC_INT_STATUS_REG, reg,
-			       reg & mask, len * byte_time_ns, 100000))
+	if (regmap_field_read_poll_timeout(hdmi->field_ddc_int_status, reg,
+					   reg & mask, len * byte_time_ns,
+					   100000))
 		return -ETIMEDOUT;
 
 	if (reg & SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK)
 		return -EIO;
 
 	if (read)
-		readsb(hdmi->base + SUN4I_HDMI_DDC_FIFO_DATA_REG, buf, len);
+		readsb(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len);
 	else
-		writesb(hdmi->base + SUN4I_HDMI_DDC_FIFO_DATA_REG, buf, len);
+		writesb(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len);
 
-	/* Clear FIFO request bit */
-	writel(SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST,
-	       hdmi->base + SUN4I_HDMI_DDC_INT_STATUS_REG);
+	/* Clear FIFO request bit by forcing a write to that bit */
+	regmap_field_force_write(hdmi->field_ddc_int_status,
+				 SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST);
 
 	return len;
 }
@@ -70,50 +77,52 @@ static int xfer_msg(struct sun4i_hdmi *hdmi, struct i2c_msg *msg)
 	u32 reg;
 
 	/* Set FIFO direction */
-	reg = readl(hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
-	reg &= ~SUN4I_HDMI_DDC_CTRL_FIFO_DIR_MASK;
-	reg |= (msg->flags & I2C_M_RD) ?
-	       SUN4I_HDMI_DDC_CTRL_FIFO_DIR_READ :
-	       SUN4I_HDMI_DDC_CTRL_FIFO_DIR_WRITE;
-	writel(reg, hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
+	if (hdmi->variant->ddc_fifo_has_dir) {
+		reg = readl(hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
+		reg &= ~SUN4I_HDMI_DDC_CTRL_FIFO_DIR_MASK;
+		reg |= (msg->flags & I2C_M_RD) ?
+		       SUN4I_HDMI_DDC_CTRL_FIFO_DIR_READ :
+		       SUN4I_HDMI_DDC_CTRL_FIFO_DIR_WRITE;
+		writel(reg, hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
+	}
+
+	/* Clear address register (not cleared by soft reset) */
+	regmap_field_write(hdmi->field_ddc_addr_reg, 0);
 
 	/* Set I2C address */
-	writel(SUN4I_HDMI_DDC_ADDR_SLAVE(msg->addr),
-	       hdmi->base + SUN4I_HDMI_DDC_ADDR_REG);
-
-	/* Set FIFO RX/TX thresholds and clear FIFO */
-	reg = readl(hdmi->base + SUN4I_HDMI_DDC_FIFO_CTRL_REG);
-	reg |= SUN4I_HDMI_DDC_FIFO_CTRL_CLEAR;
-	reg &= ~SUN4I_HDMI_DDC_FIFO_CTRL_RX_THRES_MASK;
-	reg |= SUN4I_HDMI_DDC_FIFO_CTRL_RX_THRES(RX_THRESHOLD);
-	reg &= ~SUN4I_HDMI_DDC_FIFO_CTRL_TX_THRES_MASK;
-	reg |= SUN4I_HDMI_DDC_FIFO_CTRL_TX_THRES(TX_THRESHOLD);
-	writel(reg, hdmi->base + SUN4I_HDMI_DDC_FIFO_CTRL_REG);
-	if (readl_poll_timeout(hdmi->base + SUN4I_HDMI_DDC_FIFO_CTRL_REG,
-			       reg,
-			       !(reg & SUN4I_HDMI_DDC_FIFO_CTRL_CLEAR),
-			       100, 2000))
+	regmap_field_write(hdmi->field_ddc_slave_addr, msg->addr);
+
+	/*
+	 * Set FIFO RX/TX thresholds and clear FIFO
+	 *
+	 * If threshold is inclusive, we can set the TX threshold to
+	 * 0 instead of 1.
+	 */
+	regmap_field_write(hdmi->field_ddc_fifo_tx_thres,
+			   hdmi->variant->ddc_fifo_thres_incl ? 0 : 1);
+	regmap_field_write(hdmi->field_ddc_fifo_rx_thres, RX_THRESHOLD);
+	regmap_field_write(hdmi->field_ddc_fifo_clear, 1);
+	if (regmap_field_read_poll_timeout(hdmi->field_ddc_fifo_clear,
+					   reg, !reg, 100, 2000))
 		return -EIO;
 
 	/* Set transfer length */
-	writel(msg->len, hdmi->base + SUN4I_HDMI_DDC_BYTE_COUNT_REG);
+	regmap_field_write(hdmi->field_ddc_byte_count, msg->len);
 
 	/* Set command */
-	writel(msg->flags & I2C_M_RD ?
-	       SUN4I_HDMI_DDC_CMD_IMPLICIT_READ :
-	       SUN4I_HDMI_DDC_CMD_IMPLICIT_WRITE,
-	       hdmi->base + SUN4I_HDMI_DDC_CMD_REG);
+	regmap_field_write(hdmi->field_ddc_cmd,
+			   msg->flags & I2C_M_RD ?
+			   SUN4I_HDMI_DDC_CMD_IMPLICIT_READ :
+			   SUN4I_HDMI_DDC_CMD_IMPLICIT_WRITE);
 
-	/* Clear interrupt status bits */
-	writel(SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK |
-	       SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST |
-	       SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE,
-	       hdmi->base + SUN4I_HDMI_DDC_INT_STATUS_REG);
+	/* Clear interrupt status bits by forcing a write */
+	regmap_field_force_write(hdmi->field_ddc_int_status,
+				 SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK |
+				 SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST |
+				 SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE);
 
 	/* Start command */
-	reg = readl(hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
-	writel(reg | SUN4I_HDMI_DDC_CTRL_START_CMD,
-	       hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
+	regmap_field_write(hdmi->field_ddc_start, 1);
 
 	/* Transfer bytes */
 	for (i = 0; i < msg->len; i += len) {
@@ -124,14 +133,12 @@ static int xfer_msg(struct sun4i_hdmi *hdmi, struct i2c_msg *msg)
 	}
 
 	/* Wait for command to finish */
-	if (readl_poll_timeout(hdmi->base + SUN4I_HDMI_DDC_CTRL_REG,
-			       reg,
-			       !(reg & SUN4I_HDMI_DDC_CTRL_START_CMD),
-			       100, 100000))
+	if (regmap_field_read_poll_timeout(hdmi->field_ddc_start,
+					   reg, !reg, 100, 100000))
 		return -EIO;
 
 	/* Check for errors */
-	reg = readl(hdmi->base + SUN4I_HDMI_DDC_INT_STATUS_REG);
+	regmap_field_read(hdmi->field_ddc_int_status, &reg);
 	if ((reg & SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK) ||
 	    !(reg & SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE)) {
 		return -EIO;
@@ -154,20 +161,21 @@ static int sun4i_hdmi_i2c_xfer(struct i2c_adapter *adap,
 			return -EINVAL;
 	}
 
+	/* DDC clock needs to be enabled for the module to work */
+	clk_prepare_enable(hdmi->ddc_clk);
+	clk_set_rate(hdmi->ddc_clk, 100000);
+
 	/* Reset I2C controller */
-	writel(SUN4I_HDMI_DDC_CTRL_ENABLE | SUN4I_HDMI_DDC_CTRL_RESET,
-	       hdmi->base + SUN4I_HDMI_DDC_CTRL_REG);
-	if (readl_poll_timeout(hdmi->base + SUN4I_HDMI_DDC_CTRL_REG, reg,
-			       !(reg & SUN4I_HDMI_DDC_CTRL_RESET),
-			       100, 2000))
+	regmap_field_write(hdmi->field_ddc_en, 1);
+	regmap_field_write(hdmi->field_ddc_reset, 1);
+	if (regmap_field_read_poll_timeout(hdmi->field_ddc_reset,
+					   reg, !reg, 100, 2000)) {
+		clk_disable_unprepare(hdmi->ddc_clk);
 		return -EIO;
+	}
 
-	writel(SUN4I_HDMI_DDC_LINE_CTRL_SDA_ENABLE |
-	       SUN4I_HDMI_DDC_LINE_CTRL_SCL_ENABLE,
-	       hdmi->base + SUN4I_HDMI_DDC_LINE_CTRL_REG);
-
-	clk_prepare_enable(hdmi->ddc_clk);
-	clk_set_rate(hdmi->ddc_clk, 100000);
+	regmap_field_write(hdmi->field_ddc_sck_en, 1);
+	regmap_field_write(hdmi->field_ddc_sda_en, 1);
 
 	for (i = 0; i < num; i++) {
 		err = xfer_msg(hdmi, &msgs[i]);
@@ -191,12 +199,105 @@ static const struct i2c_algorithm sun4i_hdmi_i2c_algorithm = {
 	.functionality	= sun4i_hdmi_i2c_func,
 };
 
+static int sun4i_hdmi_init_regmap_fields(struct sun4i_hdmi *hdmi)
+{
+	hdmi->field_ddc_en =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_en);
+	if (IS_ERR(hdmi->field_ddc_en))
+		return PTR_ERR(hdmi->field_ddc_en);
+
+	hdmi->field_ddc_start =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_start);
+	if (IS_ERR(hdmi->field_ddc_start))
+		return PTR_ERR(hdmi->field_ddc_start);
+
+	hdmi->field_ddc_reset =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_reset);
+	if (IS_ERR(hdmi->field_ddc_reset))
+		return PTR_ERR(hdmi->field_ddc_reset);
+
+	hdmi->field_ddc_addr_reg =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_addr_reg);
+	if (IS_ERR(hdmi->field_ddc_addr_reg))
+		return PTR_ERR(hdmi->field_ddc_addr_reg);
+
+	hdmi->field_ddc_slave_addr =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_slave_addr);
+	if (IS_ERR(hdmi->field_ddc_slave_addr))
+		return PTR_ERR(hdmi->field_ddc_slave_addr);
+
+	hdmi->field_ddc_int_mask =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_int_mask);
+	if (IS_ERR(hdmi->field_ddc_int_mask))
+		return PTR_ERR(hdmi->field_ddc_int_mask);
+
+	hdmi->field_ddc_int_status =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_int_status);
+	if (IS_ERR(hdmi->field_ddc_int_status))
+		return PTR_ERR(hdmi->field_ddc_int_status);
+
+	hdmi->field_ddc_fifo_clear =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_fifo_clear);
+	if (IS_ERR(hdmi->field_ddc_fifo_clear))
+		return PTR_ERR(hdmi->field_ddc_fifo_clear);
+
+	hdmi->field_ddc_fifo_rx_thres =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_fifo_rx_thres);
+	if (IS_ERR(hdmi->field_ddc_fifo_rx_thres))
+		return PTR_ERR(hdmi->field_ddc_fifo_rx_thres);
+
+	hdmi->field_ddc_fifo_tx_thres =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_fifo_tx_thres);
+	if (IS_ERR(hdmi->field_ddc_fifo_tx_thres))
+		return PTR_ERR(hdmi->field_ddc_fifo_tx_thres);
+
+	hdmi->field_ddc_byte_count =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_byte_count);
+	if (IS_ERR(hdmi->field_ddc_byte_count))
+		return PTR_ERR(hdmi->field_ddc_byte_count);
+
+	hdmi->field_ddc_cmd =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_cmd);
+	if (IS_ERR(hdmi->field_ddc_cmd))
+		return PTR_ERR(hdmi->field_ddc_cmd);
+
+	hdmi->field_ddc_sda_en =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_sda_en);
+	if (IS_ERR(hdmi->field_ddc_sda_en))
+		return PTR_ERR(hdmi->field_ddc_sda_en);
+
+	hdmi->field_ddc_sck_en =
+		devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
+					hdmi->variant->field_ddc_sck_en);
+	if (IS_ERR(hdmi->field_ddc_sck_en))
+		return PTR_ERR(hdmi->field_ddc_sck_en);
+
+	return 0;
+}
+
 int sun4i_hdmi_i2c_create(struct device *dev, struct sun4i_hdmi *hdmi)
 {
 	struct i2c_adapter *adap;
 	int ret = 0;
 
-	ret = sun4i_ddc_create(hdmi, hdmi->tmds_clk);
+	ret = sun4i_ddc_create(hdmi, hdmi->ddc_parent_clk);
+	if (ret)
+		return ret;
+
+	ret = sun4i_hdmi_init_regmap_fields(hdmi);
 	if (ret)
 		return ret;