[PATCH v3 4/8] serial: qcom-geni: Use geni_se_set_rate() for source clock configuration

[Praveen Talari]

On the SA8255P platform there is no Linux clock handler for the SE
source clock, so the driver has no way to compute the divider needed
for a requested baud rate. To work around this, firmware instead
exposes the SE HW supported source clock frequencies as OPPs on the
perf domain device.

geni_se_domain_attach() now populates clk_perf_tbl from
the performance-domain OPP table, allowing firmware-managed
platforms to use geni_se_clk_freq_match().

Call geni_serial_set_rate() unconditionally from
qcom_geni_serial_set_termios(), and use geni_se_set_rate() instead of
dev_pm_opp_set_rate() so clock programming is handled centrally by
the GENI core, independent of the underlying clock-control mechanism.

Reviewed-by: Mukesh Kumar Savaliya <mukesh.savaliya at oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari at oss.qualcomm.com>
---
 drivers/tty/serial/qcom_geni_serial.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 4a6f526340b8..23e423009255 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -113,7 +113,6 @@ struct qcom_geni_device_data {
 	bool console;
 	enum geni_se_xfer_mode mode;
 	int (*resources_init)(struct geni_se *se);
-	int (*set_rate)(struct geni_se *se, unsigned long baud);
 	int (*power_on)(struct geni_se *se);
 	int (*power_off)(struct geni_se *se);
 };
@@ -1461,7 +1460,10 @@ static int geni_serial_set_rate(struct geni_se *se, unsigned long baud)
 
 	uport->uartclk = clk_rate;
 	port->clk_rate = clk_rate;
-	dev_pm_opp_set_rate(uport->dev, clk_rate);
+	ret = geni_se_set_rate(&port->se, clk_rate);
+	if (ret)
+		return ret;
+
 	ser_clk_cfg = SER_CLK_EN;
 	ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
 
@@ -1499,7 +1501,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	/* baud rate */
 	baud = uart_get_baud_rate(uport, termios, old, 300, 8000000);
 
-	ret = port->dev_data->set_rate(&port->se, baud);
+	ret = geni_serial_set_rate(&port->se, baud);
 	if (ret)
 		return;
 
@@ -2051,15 +2053,19 @@ static void qcom_geni_serial_remove(struct platform_device *pdev)
 static int __maybe_unused qcom_geni_serial_runtime_suspend(struct device *dev)
 {
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
+	int ret;
 
-	return port->dev_data->power_off ?
-	       port->dev_data->power_off(&port->se) : 0;
+	ret = port->dev_data->power_off ?
+	      port->dev_data->power_off(&port->se) : 0;
+	if (ret)
+		return ret;
+
+	return geni_se_set_rate(&port->se, 0);
 }
 
 static int __maybe_unused qcom_geni_serial_runtime_resume(struct device *dev)
 {
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
-	struct uart_port *uport = &port->uport;
 	int ret;
 
 	if (port->dev_data->power_on) {
@@ -2068,8 +2074,8 @@ static int __maybe_unused qcom_geni_serial_runtime_resume(struct device *dev)
 			return ret;
 	}
 
-	if (port->se.has_opp && port->clk_rate)
-		return dev_pm_opp_set_rate(uport->dev, port->clk_rate);
+	if (port->clk_rate)
+		return geni_se_set_rate(&port->se, port->clk_rate);
 
 	return 0;
 }
@@ -2130,7 +2136,6 @@ static const struct qcom_geni_device_data qcom_geni_console_data = {
 	.console = true,
 	.mode = GENI_SE_FIFO,
 	.resources_init = geni_se_resources_init,
-	.set_rate = geni_serial_set_rate,
 	.power_on = geni_se_resources_activate,
 	.power_off = geni_se_resources_deactivate,
 };
@@ -2139,7 +2144,6 @@ static const struct qcom_geni_device_data sa8255p_qcom_geni_console_data = {
 	.console = true,
 	.mode = GENI_SE_FIFO,
 	.resources_init = geni_se_domain_attach,
-	.set_rate = geni_se_set_perf_level,
 };
 #endif
 
@@ -2147,7 +2151,6 @@ static const struct qcom_geni_device_data qcom_geni_uart_data = {
 	.console = false,
 	.mode = GENI_SE_DMA,
 	.resources_init = geni_se_resources_init,
-	.set_rate = geni_serial_set_rate,
 	.power_on = geni_se_resources_activate,
 	.power_off = geni_se_resources_deactivate,
 };
@@ -2156,7 +2159,6 @@ static const struct qcom_geni_device_data sa8255p_qcom_geni_uart_data = {
 	.console = false,
 	.mode = GENI_SE_DMA,
 	.resources_init = geni_se_domain_attach,
-	.set_rate = geni_se_set_perf_level,
 };
 
 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {

-- 
2.34.1