Re: [PATCH 02/21] tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state

[Akash Asthana]

Hi Rajendra,

On 4/10/2020 12:26 PM, Akash Asthana wrote:
> Hi Rajendra,
>
> On 4/8/2020 7:16 PM, Rajendra Nayak wrote:
> > geni serial needs to express a perforamnce state requirement on CX
> *performance
> > 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@xxxxxxxxxxxxxx>
> > Cc: Akash Asthana <akashast@xxxxxxxxxxxxxx>
> > Cc: linux-serial@xxxxxxxxxxxxxxx
> > ---
> > Â drivers/tty/serial/qcom_geni_serial.c | 20 +++++++++++++++-----
> > Â include/linux/qcom-geni-se.hÂÂÂÂÂÂÂÂÂ |Â 2 ++
> > Â 2 files changed, 17 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/tty/serial/qcom_geni_serial.c 
> > b/drivers/tty/serial/qcom_geni_serial.c
> > index 6119090..754eaf6 100644
> > --- a/drivers/tty/serial/qcom_geni_serial.c
> > +++ b/drivers/tty/serial/qcom_geni_serial.c
> > @@ -9,6 +9,7 @@
> > Â #include <linux/module.h>
> > Â #include <linux/of.h>
> > Â #include <linux/of_device.h>
> > +#include <linux/pm_opp.h>
> > Â #include <linux/platform_device.h>
> > Â #include <linux/pm_runtime.h>
> > Â #include <linux/pm_wakeirq.h>
> > @@ -961,7 +962,7 @@ static void qcom_geni_serial_set_termios(struct 
> > uart_port *uport,
> > ÂÂÂÂÂÂÂÂÂ goto out_restart_rx;
> > Â ÂÂÂÂÂ uport->uartclk = clk_rate;
> > -ÂÂÂ clk_set_rate(port->se.clk, clk_rate);
> > +ÂÂÂ dev_pm_opp_set_rate(uport->dev, clk_rate);
>
> Is this change not intended for backward compatibility? If I don't 
> pick DT change for Geni drivers, dev_pm_opp_set_rate is failing and 
> causing functionality issues.

oops Sorry, 1st patch is intended for backward compatibility. Which I 
missed earlier.

Regards,

Akash

> > ÂÂÂÂÂ ser_clk_cfg = SER_CLK_EN;
> > ÂÂÂÂÂ ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
> > Â @@ -1198,8 +1199,10 @@ static void qcom_geni_serial_pm(struct 
> > uart_port *uport,
> > ÂÂÂÂÂ if (new_state == UART_PM_STATE_ON && old_state == 
> > UART_PM_STATE_OFF)
> > ÂÂÂÂÂÂÂÂÂ geni_se_resources_on(&port->se);
> > ÂÂÂÂÂ else if (new_state == UART_PM_STATE_OFF &&
> > -ÂÂÂÂÂÂÂÂÂÂÂ old_state == UART_PM_STATE_ON)
> > +ÂÂÂÂÂÂÂÂÂÂÂ old_state == UART_PM_STATE_ON) {
> > +ÂÂÂÂÂÂÂ dev_pm_opp_set_rate(uport->dev, 0);
> > ÂÂÂÂÂÂÂÂÂ geni_se_resources_off(&port->se);
> > +ÂÂÂ }
> > Â }
> > Â Â static const struct uart_ops qcom_geni_console_pops = {
> > @@ -1318,13 +1321,16 @@ static int qcom_geni_serial_probe(struct 
> > platform_device *pdev)
> > ÂÂÂÂÂ if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
> > ÂÂÂÂÂÂÂÂÂ port->cts_rts_swap = true;
> > Â +ÂÂÂ port->se.opp = dev_pm_opp_set_clkname(&pdev->dev, "se");
> > +ÂÂÂ dev_pm_opp_of_add_table(&pdev->dev);
> > +
> > ÂÂÂÂÂ uport->private_data = drv;
> > ÂÂÂÂÂ platform_set_drvdata(pdev, port);
> > ÂÂÂÂÂ port->handle_rx = console ? handle_rx_console : handle_rx_uart;
> > Â ÂÂÂÂÂ ret = uart_add_one_port(drv, uport);
> > ÂÂÂÂÂ if (ret)
> > -ÂÂÂÂÂÂÂ return ret;
> > +ÂÂÂÂÂÂÂ goto err;
> > Â ÂÂÂÂÂ irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
> > ÂÂÂÂÂ ret = devm_request_irq(uport->dev, uport->irq, 
> > qcom_geni_serial_isr,
> > @@ -1332,7 +1338,7 @@ static int qcom_geni_serial_probe(struct 
> > platform_device *pdev)
> > ÂÂÂÂÂ if (ret) {
> > ÂÂÂÂÂÂÂÂÂ dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
> > ÂÂÂÂÂÂÂÂÂ uart_remove_one_port(drv, uport);
> > -ÂÂÂÂÂÂÂ return ret;
> > +ÂÂÂÂÂÂÂ goto err;
> > ÂÂÂÂÂ }
> > Â ÂÂÂÂÂ /*
> > @@ -1349,11 +1355,14 @@ static int qcom_geni_serial_probe(struct 
> > platform_device *pdev)
> > ÂÂÂÂÂÂÂÂÂ if (ret) {
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂ device_init_wakeup(&pdev->dev, false);
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂ uart_remove_one_port(drv, uport);
> > -ÂÂÂÂÂÂÂÂÂÂÂ return ret;
> > +ÂÂÂÂÂÂÂÂÂÂÂ goto err;
> > ÂÂÂÂÂÂÂÂÂ }
> > ÂÂÂÂÂ }
> > Â ÂÂÂÂÂ return 0;
> > +err:
> > +ÂÂÂ dev_pm_opp_of_remove_table(&pdev->dev);
> do we need to call "dev_pm_opp_put_clkname" here and in remove to 
> release clk resource grabbed by
>
> dev_pm_opp_set_clkname(&pdev->dev, "se");?
>
> Regards,
> Akash
>
> > +ÂÂÂ return ret;
> > Â }
> > Â Â static int qcom_geni_serial_remove(struct platform_device *pdev)
> > @@ -1361,6 +1370,7 @@ static int qcom_geni_serial_remove(struct 
> > platform_device *pdev)
> > ÂÂÂÂÂ struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
> > ÂÂÂÂÂ struct uart_driver *drv = port->uport.private_data;
> > Â +ÂÂÂ dev_pm_opp_of_remove_table(&pdev->dev);
> > ÂÂÂÂÂ dev_pm_clear_wake_irq(&pdev->dev);
> > ÂÂÂÂÂ device_init_wakeup(&pdev->dev, false);
> > ÂÂÂÂÂ 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..737e713 100644
> > --- a/include/linux/qcom-geni-se.h
> > +++ b/include/linux/qcom-geni-se.h
> > @@ -24,6 +24,7 @@ enum geni_se_protocol_type {
> > Â Â struct geni_wrapper;
> > Â struct clk;
> > +struct opp_table;
> > Â Â /**
> > ÂÂ * struct geni_se - GENI Serial Engine
> > @@ -39,6 +40,7 @@ struct geni_se {
> > ÂÂÂÂÂ struct device *dev;
> > ÂÂÂÂÂ struct geni_wrapper *wrapper;
> > ÂÂÂÂÂ struct clk *clk;
> > +ÂÂÂ struct opp_table *opp;
> > ÂÂÂÂÂ unsigned int num_clk_levels;
> > ÂÂÂÂÂ unsigned long *clk_perf_tbl;
> > Â };
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project