[RFC v2 03/11] tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state

Rajendra Nayak
2019-03-20T09:49:55Z

geni serial needs to express a perforamnce state requirement on CX
depending on the frequency of the clock rates. Use OPP table from
DT to register with OPP framework and use dev_pm_opp_set_rate() to
set the clk/perf state.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
drivers/tty/serial/qcom_geni_serial.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 3bcec1c20219..422852911141 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/qcom-geni-se.h>
#include <linux/serial.h>
@@ -115,6 +116,7 @@ struct qcom_geni_serial_port {
bool brk;

unsigned int tx_remaining;
+ struct device *dev;
};

static const struct uart_ops qcom_geni_console_pops;
@@ -961,7 +963,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
goto out_restart_rx;

uport->uartclk = clk_rate;
- clk_set_rate(port->se.clk, clk_rate);
+ dev_pm_opp_set_rate(port->dev, clk_rate);
ser_clk_cfg = SER_CLK_EN;
ser_clk_cfg |= clk_div << CLK_DIV_SHFT;

@@ -1198,8 +1200,10 @@ static void qcom_geni_serial_pm(struct uart_port *uport,
if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF)
geni_se_resources_on(&port->se);
else if (new_state == UART_PM_STATE_OFF &&
- old_state == UART_PM_STATE_ON)
+ old_state == UART_PM_STATE_ON) {
+ dev_pm_opp_set_rate(port->dev, 0);
geni_se_resources_off(&port->se);
+ }
}

static const struct uart_ops qcom_geni_console_pops = {
@@ -1265,6 +1269,7 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "Invalid line %d\n", line);
return PTR_ERR(port);
}
+ port->dev = &pdev->dev;

uport = &port->uport;
/* Don't allow 2 drivers to access the same port */
@@ -1286,6 +1291,12 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
return -EINVAL;
uport->mapbase = res->start;

+ ret = dev_pm_opp_of_add_table(&pdev->dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to init OPP table: %d\n", ret);
+ return ret;
+ }
+
port->tx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;