geni serial needs to express a perforamnce state requirement on CX
powerdomain 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 <rna...@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <m...@chromium.org>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Akash Asthana <akash...@codeaurora.org>
Cc: linux-ser...@vger.kernel.org
---
 drivers/tty/serial/qcom_geni_serial.c | 34 +++++++++++++++++++++++++++++-----
 include/linux/qcom-geni-se.h          |  4 ++++
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c 
b/drivers/tty/serial/qcom_geni_serial.c
index 6119090..dd3d1ba 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -9,6 +9,7 @@
 #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/pm_runtime.h>
 #include <linux/pm_wakeirq.h>
@@ -961,7 +962,7 @@ 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(uport->dev, clk_rate);
        ser_clk_cfg = SER_CLK_EN;
        ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
 
@@ -1198,8 +1199,11 @@ 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) {
+               /* Drop the performance state vote */
+               dev_pm_opp_set_rate(uport->dev, 0);
                geni_se_resources_off(&port->se);
+       }
 }
 
 static const struct uart_ops qcom_geni_console_pops = {
@@ -1318,13 +1322,25 @@ static int qcom_geni_serial_probe(struct 
platform_device *pdev)
        if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
                port->cts_rts_swap = true;
 
+       port->se.opp_table = dev_pm_opp_set_clkname(&pdev->dev, "se");
+       if (IS_ERR(port->se.opp_table))
+               return PTR_ERR(port->se.opp_table);
+       /* OPP table is optional */
+       ret = dev_pm_opp_of_add_table(&pdev->dev);
+       if (!ret) {
+               port->se.has_opp_table = true;
+       } else if (ret != -ENODEV) {
+               dev_err(&pdev->dev, "invalid OPP table in device tree\n");
+               return ret;
+       }
+
        uport->private_data = drv;
        platform_set_drvdata(pdev, port);
        port->handle_rx = console ? handle_rx_console : handle_rx_uart;
 
        ret = uart_add_one_port(drv, uport);
        if (ret)
-               return ret;
+               goto err;
 
        irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
        ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
@@ -1332,7 +1348,7 @@ static int qcom_geni_serial_probe(struct platform_device 
*pdev)
        if (ret) {
                dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
                uart_remove_one_port(drv, uport);
-               return ret;
+               goto err;
        }
 
        /*
@@ -1349,11 +1365,16 @@ static int qcom_geni_serial_probe(struct 
platform_device *pdev)
                if (ret) {
                        device_init_wakeup(&pdev->dev, false);
                        uart_remove_one_port(drv, uport);
-                       return ret;
+                       goto err;
                }
        }
 
        return 0;
+err:
+       if (port->se.has_opp_table)
+               dev_pm_opp_of_remove_table(&pdev->dev);
+       dev_pm_opp_put_clkname(port->se.opp_table);
+       return ret;
 }
 
 static int qcom_geni_serial_remove(struct platform_device *pdev)
@@ -1361,6 +1382,9 @@ static int qcom_geni_serial_remove(struct platform_device 
*pdev)
        struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
        struct uart_driver *drv = port->uport.private_data;
 
+       if (port->se.has_opp_table)
+               dev_pm_opp_of_remove_table(&pdev->dev);
+       dev_pm_opp_put_clkname(port->se.opp_table);
        dev_pm_clear_wake_irq(&pdev->dev);
        device_init_wakeup(&pdev->dev, false);
        uart_remove_one_port(drv, &port->uport);
diff --git a/include/linux/qcom-geni-se.h b/include/linux/qcom-geni-se.h
index dd46494..6b78094 100644
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -33,6 +33,8 @@ struct clk;
  * @clk:               Handle to the core serial engine clock
  * @num_clk_levels:    Number of valid clock levels in clk_perf_tbl
  * @clk_perf_tbl:      Table of clock frequency input to serial engine clock
+ * @opp_table:         Pointer to the OPP table
+ * @has_opp_table:     Specifies if the SE has an OPP table
  */
 struct geni_se {
        void __iomem *base;
@@ -41,6 +43,8 @@ struct geni_se {
        struct clk *clk;
        unsigned int num_clk_levels;
        unsigned long *clk_perf_tbl;
+       struct opp_table *opp_table;
+       bool has_opp_table;
 };
 
 /* Common SE registers */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Reply via email to