Re: [PATCH v3 2/2] serial: fsl_linflexuart: add clock support

From: Frank Li
Date: Thu Nov 07 2024 - 10:19:25 EST


On Thu, Nov 07, 2024 at 01:46:11PM +0200, Ciprian Costea wrote:
> From: Ciprian Marian Costea <ciprianmarian.costea@xxxxxxxxxxx>
>
> Add clocking support to the NXP LINFlexD UART driver.
> It is used by S32G2 and S32G3 SoCs.
> Clocking support is added as optional in order to not break
> existing support for S32V234 SoC.

wrap at 75 char.

Add optional clock 'lin' and 'ipg' support to NXP LINFlexD UART driver,
which used by S22G2 and S32G3.

>
> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@xxxxxxxxxxx>
> ---
> drivers/tty/serial/fsl_linflexuart.c | 67 +++++++++++++++++++++-------
> 1 file changed, 51 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
> index e972df4b188d..23aed3bbff6c 100644
> --- a/drivers/tty/serial/fsl_linflexuart.c
> +++ b/drivers/tty/serial/fsl_linflexuart.c
> @@ -3,9 +3,10 @@
> * Freescale LINFlexD UART serial port driver
> *
> * Copyright 2012-2016 Freescale Semiconductor, Inc.
> - * Copyright 2017-2019 NXP
> + * Copyright 2017-2019, 2024 NXP
> */
>
> +#include <linux/clk.h>
> #include <linux/console.h>
> #include <linux/io.h>
> #include <linux/irq.h>
> @@ -120,6 +121,12 @@
>
> #define PREINIT_DELAY 2000 /* us */
>
> +struct linflex_port {
> + struct uart_port port;
> + struct clk *clk_lin;
> + struct clk *clk_ipg;

Please clk bulk

> +};
> +
> static const struct of_device_id linflex_dt_ids[] = {
> {
> .compatible = "fsl,s32v234-linflexuart",
> @@ -807,12 +814,13 @@ static struct uart_driver linflex_reg = {
> static int linflex_probe(struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> + struct linflex_port *lfport;
> struct uart_port *sport;
> struct resource *res;
> int ret;
>
> - sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
> - if (!sport)
> + lfport = devm_kzalloc(&pdev->dev, sizeof(*lfport), GFP_KERNEL);
> + if (!lfport)
> return -ENOMEM;
>
> ret = of_alias_get_id(np, "serial");
> @@ -826,6 +834,7 @@ static int linflex_probe(struct platform_device *pdev)
> return -ENOMEM;
> }
>
> + sport = &lfport->port;
> sport->line = ret;
>
> sport->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> @@ -844,39 +853,65 @@ static int linflex_probe(struct platform_device *pdev)
> sport->flags = UPF_BOOT_AUTOCONF;
> sport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE);
>
> - linflex_ports[sport->line] = sport;
> + lfport->clk_lin = devm_clk_get_optional_enabled(&pdev->dev, "lin");
> + if (IS_ERR(lfport->clk_lin))
> + return dev_err_probe(&pdev->dev, PTR_ERR(lfport->clk_lin),
> + "Failed to get linflexuart clk\n");
>
> - platform_set_drvdata(pdev, sport);
> + lfport->clk_ipg = devm_clk_get_optional_enabled(&pdev->dev, "ipg");
> + if (IS_ERR(lfport->clk_ipg))
> + return dev_err_probe(&pdev->dev, PTR_ERR(lfport->clk_ipg),
> + "Failed to get linflexuart ipg clk\n");
> +

use clk bulk API to simple code.

> + linflex_ports[sport->line] = sport;
> + platform_set_drvdata(pdev, lfport);
>
> return uart_add_one_port(&linflex_reg, sport);
> }
>
> static void linflex_remove(struct platform_device *pdev)
> {
> - struct uart_port *sport = platform_get_drvdata(pdev);
> + struct linflex_port *lfport = platform_get_drvdata(pdev);
>
> - uart_remove_one_port(&linflex_reg, sport);
> + uart_remove_one_port(&linflex_reg, &lfport->port);
> }
>
> -#ifdef CONFIG_PM_SLEEP

Not related change. If change CONFIG_PM, please use sperate patch.
Please ref
https://lore.kernel.org/imx/1713848917-13380-1-git-send-email-shengjiu.wang@xxxxxxx/

> -static int linflex_suspend(struct device *dev)
> +static int __maybe_unused linflex_suspend(struct device *dev)
> {
> - struct uart_port *sport = dev_get_drvdata(dev);
> + struct linflex_port *lfport = dev_get_drvdata(dev);
> +
> + uart_suspend_port(&linflex_reg, &lfport->port);
>
> - uart_suspend_port(&linflex_reg, sport);
> + clk_disable_unprepare(lfport->clk_lin);
> + clk_disable_unprepare(lfport->clk_ipg);
>
> return 0;
> }
>
> -static int linflex_resume(struct device *dev)
> +static int __maybe_unused linflex_resume(struct device *dev)
> {
> - struct uart_port *sport = dev_get_drvdata(dev);
> + struct linflex_port *lfport = dev_get_drvdata(dev);
> + int ret;
>
> - uart_resume_port(&linflex_reg, sport);
> + if (lfport->clk_lin) {
> + ret = clk_prepare_enable(lfport->clk_lin);
> + if (ret) {
> + dev_err(dev, "Failed to enable linflexuart clk: %d\n", ret);
> + return ret;
> + }
> + }
>
> - return 0;
> + if (lfport->clk_ipg) {
> + ret = clk_prepare_enable(lfport->clk_ipg);
> + if (ret) {
> + dev_err(dev, "Failed to enable linflexuart ipg clk: %d\n", ret);
> + clk_disable_unprepare(lfport->clk_lin);
> + return ret;
> + }
> + }

use clk bulk api.

> +
> + return uart_resume_port(&linflex_reg, &lfport->port);
> }
> -#endif
>
> static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume);
>
> --
> 2.45.2
>