media: i2c: adv748x: Handle TX[A|B] power management

As the driver is now allowed to probe with a single output endpoint,
power management routines shall now take into account the case a CSI-2 TX
is not enabled.

Unify the adv748x_tx_power() routine to handle transparently TXA and TXB,
and enable the CSI-2 outputs conditionally.
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/i2c/adv748x/adv748x-afe.c

@@ -282,7 +282,7 @@ static int adv748x_afe_s_stream(struct v4l2_subdev *sd, int enable)
 			goto unlock;
 	}
 
-	ret = adv748x_txb_power(state, enable);
+	ret = adv748x_tx_power(&state->txb, enable);
 	if (ret)
 		goto unlock;
 

drivers/media/i2c/adv748x/adv748x-core.c

@@ -288,33 +288,16 @@ static const struct adv748x_reg_value adv748x_power_down_txb_1lane[] = {
 	{ADV748X_PAGE_EOR, 0xff, 0xff}	/* End of register table */
 };
 
-int adv748x_txa_power(struct adv748x_state *state, bool on)
+int adv748x_tx_power(struct adv748x_csi2 *tx, bool on)
 {
+	struct adv748x_state *state = tx->state;
+	const struct adv748x_reg_value *reglist;
 	int val;
 
-	val = txa_read(state, ADV748X_CSI_FS_AS_LS);
-	if (val < 0)
-		return val;
-
-	/*
-	 * This test against BIT(6) is not documented by the datasheet, but was
-	 * specified in the downstream driver.
-	 * Track with a WARN_ONCE to determine if it is ever set by HW.
-	 */
-	WARN_ONCE((on && val & ADV748X_CSI_FS_AS_LS_UNKNOWN),
-			"Enabling with unknown bit set");
-
-	if (on)
-		return adv748x_write_regs(state, adv748x_power_up_txa_4lane);
-
-	return adv748x_write_regs(state, adv748x_power_down_txa_4lane);
-}
-
-int adv748x_txb_power(struct adv748x_state *state, bool on)
-{
-	int val;
+	if (!is_tx_enabled(tx))
+		return 0;
 
-	val = txb_read(state, ADV748X_CSI_FS_AS_LS);
+	val = tx_read(tx, ADV748X_CSI_FS_AS_LS);
 	if (val < 0)
 		return val;
 
@@ -327,9 +310,13 @@ int adv748x_txb_power(struct adv748x_state *state, bool on)
 			"Enabling with unknown bit set");
 
 	if (on)
-		return adv748x_write_regs(state, adv748x_power_up_txb_1lane);
+		reglist = is_txa(tx) ? adv748x_power_up_txa_4lane :
+				       adv748x_power_up_txb_1lane;
+	else
+		reglist = is_txa(tx) ? adv748x_power_down_txa_4lane :
+				       adv748x_power_down_txb_1lane;
 
-	return adv748x_write_regs(state, adv748x_power_down_txb_1lane);
+	return adv748x_write_regs(state, reglist);
 }
 
 /* -----------------------------------------------------------------------------
@@ -478,6 +465,7 @@ static const struct adv748x_reg_value adv748x_init_txb_1lane[] = {
 static int adv748x_reset(struct adv748x_state *state)
 {
 	int ret;
+	u8 regval = ADV748X_IO_10_PIX_OUT_EN;
 
 	ret = adv748x_write_regs(state, adv748x_sw_reset);
 	if (ret < 0)
@@ -492,22 +480,24 @@ static int adv748x_reset(struct adv748x_state *state)
 	if (ret)
 		return ret;
 
-	adv748x_txa_power(state, 0);
+	adv748x_tx_power(&state->txa, 0);
 
 	/* Init and power down TXB */
 	ret = adv748x_write_regs(state, adv748x_init_txb_1lane);
 	if (ret)
 		return ret;
 
-	adv748x_txb_power(state, 0);
+	adv748x_tx_power(&state->txb, 0);
 
 	/* Disable chip powerdown & Enable HDMI Rx block */
 	io_write(state, ADV748X_IO_PD, ADV748X_IO_PD_RX_EN);
 
-	/* Enable 4-lane CSI Tx & Pixel Port */
-	io_write(state, ADV748X_IO_10, ADV748X_IO_10_CSI4_EN |
-				       ADV748X_IO_10_CSI1_EN |
-				       ADV748X_IO_10_PIX_OUT_EN);
+	/* Conditionally enable TXa and TXb. */
+	if (is_tx_enabled(&state->txa))
+		regval |= ADV748X_IO_10_CSI4_EN;
+	if (is_tx_enabled(&state->txb))
+		regval |= ADV748X_IO_10_CSI1_EN;
+	io_write(state, ADV748X_IO_10, regval);
 
 	/* Use vid_std and v_freq as freerun resolution for CP */
 	cp_clrset(state, ADV748X_CP_CLMP_POS, ADV748X_CP_CLMP_POS_DIS_AUTO,

drivers/media/i2c/adv748x/adv748x-csi2.c

@@ -14,11 +14,6 @@
 
 #include "adv748x.h"
 
-static bool is_txa(struct adv748x_csi2 *tx)
-{
-	return tx == &tx->state->txa;
-}
-
 static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
 					    unsigned int vc)
 {

drivers/media/i2c/adv748x/adv748x-hdmi.c

@@ -358,7 +358,7 @@ static int adv748x_hdmi_s_stream(struct v4l2_subdev *sd, int enable)
 
 	mutex_lock(&state->mutex);
 
-	ret = adv748x_txa_power(state, enable);
+	ret = adv748x_tx_power(&state->txa, enable);
 	if (ret)
 		goto done;
 

drivers/media/i2c/adv748x/adv748x.h

@@ -89,6 +89,7 @@ struct adv748x_csi2 {
 #define notifier_to_csi2(n) container_of(n, struct adv748x_csi2, notifier)
 #define adv748x_sd_to_csi2(sd) container_of(sd, struct adv748x_csi2, sd)
 #define is_tx_enabled(_tx) ((_tx)->state->endpoints[(_tx)->port] != NULL)
+#define is_txa(_tx) ((_tx) == &(_tx)->state->txa)
 
 enum adv748x_hdmi_pads {
 	ADV748X_HDMI_SINK,
@@ -374,9 +375,6 @@ int adv748x_write_block(struct adv748x_state *state, int client_page,
 #define cp_write(s, r, v) adv748x_write(s, ADV748X_PAGE_CP, r, v)
 #define cp_clrset(s, r, m, v) cp_write(s, r, (cp_read(s, r) & ~m) | v)
 
-#define txa_read(s, r) adv748x_read(s, ADV748X_PAGE_TXA, r)
-#define txb_read(s, r) adv748x_read(s, ADV748X_PAGE_TXB, r)
-
 #define tx_read(t, r) adv748x_read(t->state, t->page, r)
 #define tx_write(t, r, v) adv748x_write(t->state, t->page, r, v)
 
@@ -396,8 +394,7 @@ void adv748x_subdev_init(struct v4l2_subdev *sd, struct adv748x_state *state,
 int adv748x_register_subdevs(struct adv748x_state *state,
 			     struct v4l2_device *v4l2_dev);
 
-int adv748x_txa_power(struct adv748x_state *state, bool on);
-int adv748x_txb_power(struct adv748x_state *state, bool on);
+int adv748x_tx_power(struct adv748x_csi2 *tx, bool on);
 
 int adv748x_afe_init(struct adv748x_afe *afe);
 void adv748x_afe_cleanup(struct adv748x_afe *afe);