tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state

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 <rnayak@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Akash Asthana <akashast@codeaurora.org>
Cc: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/1592222564-13556-2-git-send-email-rnayak@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index f701c7e..0300867 100644 (file)
--- 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>
@@ -963,7 +964,7 @@ 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;
 
@@ -1383,13 +1384,25 @@ 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,
@@ -1397,7 +1410,7 @@ 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;
        }
 
        /*
@@ -1414,11 +1427,16 @@ 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)
@@ -1426,6 +1444,9 @@ 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 743dd97..afa511e 100644 (file)
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -47,6 +47,8 @@ struct geni_icc_path {
  * @num_clk_levels:    Number of valid clock levels in clk_perf_tbl
  * @clk_perf_tbl:      Table of clock frequency input to serial engine clock
  * @icc_paths:         Array of ICC paths for SE
+ * @opp_table:         Pointer to the OPP table
+ * @has_opp_table:     Specifies if the SE has an OPP table
  */
 struct geni_se {
        void __iomem *base;
@@ -56,6 +58,8 @@ struct geni_se {
        unsigned int num_clk_levels;
        unsigned long *clk_perf_tbl;
        struct geni_icc_path icc_paths[3];
+       struct opp_table *opp_table;
+       bool has_opp_table;
 };
 
 /* Common SE registers */