[PATCH V4 7/9] tty: serial: qcom_geni_serial: Add interconnect support

[Akash Asthana <akashast@xxxxxxxxxxxxxx>]

Get the interconnect paths for Uart based Serial Engine device
and vote according to the baud rate requirement of the driver.

Signed-off-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
---
Changes in V2:
 - As per Bjorn's comment, removed se == NULL check from geni_serial_icc_get
 - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure
 - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting
   path handle
 - As per Matthias comment, added error handling for icc_set_bw call

Changes in V3:
 - As per Matthias comment, use common library APIs defined in geni-se
   driver for ICC functionality.

Changes in V4:
 - As per Mark's comment move peak_bw guess as twice of avg_bw if
   nothing mentioned explicitly to ICC core.
 - As per Matthias's comment select core clock BW based on baud rate.
   If it's less than 115200 go for GENI_DEFAULT_BW else CORE_2X_50_MHZ

 drivers/tty/serial/qcom_geni_serial.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 8c5d97c..a5b2f1c 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -965,6 +965,15 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	ser_clk_cfg = SER_CLK_EN;
 	ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
 
+	/*
+	 * Bump up BW vote on CPU and CORE path as driver supports FIFO mode
+	 * only.
+	 */
+	port->se.icc_paths[0].avg_bw = (baud > 115200) ?
+				Bps_to_icc(CORE_2X_50_MHZ) : GENI_DEFAULT_BW;
+	port->se.icc_paths[1].avg_bw = Bps_to_icc(baud);
+	geni_icc_vote_on(&port->se);
+
 	/* parity */
 	tx_trans_cfg = readl(uport->membase + SE_UART_TX_TRANS_CFG);
 	tx_parity_cfg = readl(uport->membase + SE_UART_TX_PARITY_CFG);
@@ -1202,11 +1211,14 @@ static void qcom_geni_serial_pm(struct uart_port *uport,
 	if (old_state == UART_PM_STATE_UNDEFINED)
 		old_state = UART_PM_STATE_OFF;
 
-	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF)
+	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF) {
+		geni_icc_vote_on(&port->se);
 		geni_se_resources_on(&port->se);
-	else if (new_state == UART_PM_STATE_OFF &&
-			old_state == UART_PM_STATE_ON)
+	} else if (new_state == UART_PM_STATE_OFF &&
+			old_state == UART_PM_STATE_ON) {
 		geni_se_resources_off(&port->se);
+		geni_icc_vote_off(&port->se);
+	}
 }
 
 static const struct uart_ops qcom_geni_console_pops = {
@@ -1304,6 +1316,13 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 			return -ENOMEM;
 	}
 
+	ret = geni_icc_get(&port->se, NULL);
+	if (ret)
+		return ret;
+	/* Set the bus quota to a reasonable value for register access */
+	port->se.icc_paths[0].avg_bw = GENI_DEFAULT_BW;
+	port->se.icc_paths[1].avg_bw = GENI_DEFAULT_BW;
+
 	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
 			"qcom_geni_serial_%s%d",
 			uart_console(uport) ? "console" : "uart", uport->line);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project