[PATCH v3 0/4] serial: atmel: cleanup code

[PATCH v3 0/4] serial: atmel: cleanup code

[Claudiu Beznea]

Hi,

The following patches does some cleanup for atmel_serial driver by
switching to dev_pm_ops and improving clock management code. Along with
it I took the chance and introduced a patch for st-asc which removes the
include of pm_runtime.h.

Thank you,
Claudiu Beznea

Changes in v3:
- removed "int ret;" from atmel_console_setup() as suggested in
  the review of v1
  
Changes in v2:
- split patch 2/3 from v1 in patch 2/4 and patch 3/4 in this
  series
- collected tags

Claudiu Beznea (4):
  tty: serial: atmel: stop using legacy pm ops
  tty: serial: atmel: use devm_clk_get()
  tty: serial: atmel: remove enable/disable clock due to
    atmel_console_setup()
  serial: st-asc: remove include of pm_runtime.h

 drivers/tty/serial/atmel_serial.c | 94 +++++++++----------------------
 drivers/tty/serial/st-asc.c       |  1 -
 2 files changed, 26 insertions(+), 69 deletions(-)

-- 
2.34.1

[PATCH v3 1/4] tty: serial: atmel: stop using legacy pm ops

[Claudiu Beznea]

Stop using legacy PM ops and switch using dev_pm_ops. Along with
it #ifdef CONFIG_PM are removed and __maybe_unused and pm_ptr() used
instead. Coding style recommends (at chapter Conditional Compilation)
to avoid using preprocessor conditional and use __maybe_unused
instead.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/tty/serial/atmel_serial.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 74dd1d3ac46f..c618d7e93058 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -166,7 +166,6 @@ struct atmel_uart_port {
 	unsigned int		fidi_min;
 	unsigned int		fidi_max;
 
-#ifdef CONFIG_PM
 	struct {
 		u32		cr;
 		u32		mr;
@@ -177,7 +176,6 @@ struct atmel_uart_port {
 		u32		fmr;
 		u32		fimr;
 	} cache;
-#endif
 
 	int (*prepare_rx)(struct uart_port *port);
 	int (*prepare_tx)(struct uart_port *port);
@@ -2718,7 +2716,6 @@ static struct uart_driver atmel_uart = {
 	.cons		= ATMEL_CONSOLE_DEVICE,
 };
 
-#ifdef CONFIG_PM
 static bool atmel_serial_clk_will_stop(void)
 {
 #ifdef CONFIG_ARCH_AT91
@@ -2728,10 +2725,9 @@ static bool atmel_serial_clk_will_stop(void)
 #endif
 }
 
-static int atmel_serial_suspend(struct platform_device *pdev,
-				pm_message_t state)
+static int __maybe_unused atmel_serial_suspend(struct device *dev)
 {
-	struct uart_port *port = platform_get_drvdata(pdev);
+	struct uart_port *port = dev_get_drvdata(dev);
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 
 	if (uart_console(port) && console_suspend_enabled) {
@@ -2756,14 +2752,14 @@ static int atmel_serial_suspend(struct platform_device *pdev,
 	}
 
 	/* we can not wake up if we're running on slow clock */
-	atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
+	atmel_port->may_wakeup = device_may_wakeup(dev);
 	if (atmel_serial_clk_will_stop()) {
 		unsigned long flags;
 
 		spin_lock_irqsave(&atmel_port->lock_suspended, flags);
 		atmel_port->suspended = true;
 		spin_unlock_irqrestore(&atmel_port->lock_suspended, flags);
-		device_set_wakeup_enable(&pdev->dev, 0);
+		device_set_wakeup_enable(dev, 0);
 	}
 
 	uart_suspend_port(&atmel_uart, port);
@@ -2771,9 +2767,9 @@ static int atmel_serial_suspend(struct platform_device *pdev,
 	return 0;
 }
 
-static int atmel_serial_resume(struct platform_device *pdev)
+static int __maybe_unused atmel_serial_resume(struct device *dev)
 {
-	struct uart_port *port = platform_get_drvdata(pdev);
+	struct uart_port *port = dev_get_drvdata(dev);
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 	unsigned long flags;
 
@@ -2808,14 +2804,10 @@ static int atmel_serial_resume(struct platform_device *pdev)
 	spin_unlock_irqrestore(&atmel_port->lock_suspended, flags);
 
 	uart_resume_port(&atmel_uart, port);
-	device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
+	device_set_wakeup_enable(dev, atmel_port->may_wakeup);
 
 	return 0;
 }
-#else
-#define atmel_serial_suspend NULL
-#define atmel_serial_resume NULL
-#endif
 
 static void atmel_serial_probe_fifos(struct atmel_uart_port *atmel_port,
 				     struct platform_device *pdev)
@@ -3019,14 +3011,16 @@ static int atmel_serial_remove(struct platform_device *pdev)
 	return ret;
 }
 
+static SIMPLE_DEV_PM_OPS(atmel_serial_pm_ops, atmel_serial_suspend,
+			 atmel_serial_resume);
+
 static struct platform_driver atmel_serial_driver = {
 	.probe		= atmel_serial_probe,
 	.remove		= atmel_serial_remove,
-	.suspend	= atmel_serial_suspend,
-	.resume		= atmel_serial_resume,
 	.driver		= {
 		.name			= "atmel_usart_serial",
 		.of_match_table		= of_match_ptr(atmel_serial_dt_ids),
+		.pm			= pm_ptr(&atmel_serial_pm_ops),
 	},
 };
 
-- 
2.34.1

[PATCH v3 2/4] tty: serial: atmel: use devm_clk_get()

[Claudiu Beznea]

Use devm_clk_get() for serial clock instead of clk_get()/clk_put().
With this move the clk_get in driver's probe function.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/tty/serial/atmel_serial.c | 50 ++++++++++---------------------
 1 file changed, 15 insertions(+), 35 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index c618d7e93058..4cec97fd7241 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2508,24 +2508,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
 	if (ret)
 		return ret;
 
-	/* for console, the clock could already be configured */
-	if (!atmel_port->clk) {
-		atmel_port->clk = clk_get(&mpdev->dev, "usart");
-		if (IS_ERR(atmel_port->clk)) {
-			ret = PTR_ERR(atmel_port->clk);
-			atmel_port->clk = NULL;
-			return ret;
-		}
-		ret = clk_prepare_enable(atmel_port->clk);
-		if (ret) {
-			clk_put(atmel_port->clk);
-			atmel_port->clk = NULL;
-			return ret;
-		}
-		port->uartclk = clk_get_rate(atmel_port->clk);
-		clk_disable_unprepare(atmel_port->clk);
-		/* only enable clock when USART is in use */
-	}
+	port->uartclk = clk_get_rate(atmel_port->clk);
 
 	/*
 	 * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
@@ -2896,14 +2879,23 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	atomic_set(&atmel_port->tasklet_shutdown, 0);
 	spin_lock_init(&atmel_port->lock_suspended);
 
+	atmel_port->clk = devm_clk_get(&pdev->dev, "usart");
+	if (IS_ERR(atmel_port->clk)) {
+		ret = PTR_ERR(atmel_port->clk);
+		goto err;
+	}
+	ret = clk_prepare_enable(atmel_port->clk);
+	if (ret)
+		goto err;
+
 	ret = atmel_init_port(atmel_port, pdev);
 	if (ret)
-		goto err_clear_bit;
+		goto err_clk_disable_unprepare;
 
 	atmel_port->gpios = mctrl_gpio_init(&atmel_port->uart, 0);
 	if (IS_ERR(atmel_port->gpios)) {
 		ret = PTR_ERR(atmel_port->gpios);
-		goto err_clear_bit;
+		goto err_clk_disable_unprepare;
 	}
 
 	if (!atmel_use_pdc_rx(&atmel_port->uart)) {
@@ -2912,7 +2904,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
 				     sizeof(struct atmel_uart_char),
 				     GFP_KERNEL);
 		if (!data)
-			goto err_alloc_ring;
+			goto err_clk_disable_unprepare;
 		atmel_port->rx_ring.buf = data;
 	}
 
@@ -2936,12 +2928,6 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	device_init_wakeup(&pdev->dev, 1);
 	platform_set_drvdata(pdev, atmel_port);
 
-	/*
-	 * The peripheral clock has been disabled by atmel_init_port():
-	 * enable it before accessing I/O registers
-	 */
-	clk_prepare_enable(atmel_port->clk);
-
 	if (rs485_enabled) {
 		atmel_uart_writel(&atmel_port->uart, ATMEL_US_MR,
 				  ATMEL_US_USMODE_NORMAL);
@@ -2965,12 +2951,8 @@ static int atmel_serial_probe(struct platform_device *pdev)
 err_add_port:
 	kfree(atmel_port->rx_ring.buf);
 	atmel_port->rx_ring.buf = NULL;
-err_alloc_ring:
-	if (!uart_console(&atmel_port->uart)) {
-		clk_put(atmel_port->clk);
-		atmel_port->clk = NULL;
-	}
-err_clear_bit:
+err_clk_disable_unprepare:
+	clk_disable_unprepare(atmel_port->clk);
 	clear_bit(atmel_port->uart.line, atmel_ports_in_use);
 err:
 	return ret;
@@ -3004,8 +2986,6 @@ static int atmel_serial_remove(struct platform_device *pdev)
 
 	clear_bit(port->line, atmel_ports_in_use);
 
-	clk_put(atmel_port->clk);
-	atmel_port->clk = NULL;
 	pdev->dev.of_node = NULL;
 
 	return ret;
-- 
2.34.1

Re: [PATCH v3 2/4] tty: serial: atmel: use devm_clk_get()

[Richard Genoud]

Le 16/06/2022 à 16:00, Claudiu Beznea a écrit :
> Use devm_clk_get() for serial clock instead of clk_get()/clk_put().
> With this move the clk_get in driver's probe function.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>

> ---
>   drivers/tty/serial/atmel_serial.c | 50 ++++++++++---------------------
>   1 file changed, 15 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index c618d7e93058..4cec97fd7241 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2508,24 +2508,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
>   	if (ret)
>   		return ret;
>   
> -	/* for console, the clock could already be configured */
> -	if (!atmel_port->clk) {
> -		atmel_port->clk = clk_get(&mpdev->dev, "usart");
> -		if (IS_ERR(atmel_port->clk)) {
> -			ret = PTR_ERR(atmel_port->clk);
> -			atmel_port->clk = NULL;
> -			return ret;
> -		}
> -		ret = clk_prepare_enable(atmel_port->clk);
> -		if (ret) {
> -			clk_put(atmel_port->clk);
> -			atmel_port->clk = NULL;
> -			return ret;
> -		}
> -		port->uartclk = clk_get_rate(atmel_port->clk);
> -		clk_disable_unprepare(atmel_port->clk);
> -		/* only enable clock when USART is in use */
> -	}
> +	port->uartclk = clk_get_rate(atmel_port->clk);
>   
>   	/*
>   	 * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
> @@ -2896,14 +2879,23 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   	atomic_set(&atmel_port->tasklet_shutdown, 0);
>   	spin_lock_init(&atmel_port->lock_suspended);
>   
> +	atmel_port->clk = devm_clk_get(&pdev->dev, "usart");
> +	if (IS_ERR(atmel_port->clk)) {
> +		ret = PTR_ERR(atmel_port->clk);
> +		goto err;
> +	}
> +	ret = clk_prepare_enable(atmel_port->clk);
> +	if (ret)
> +		goto err;
> +
>   	ret = atmel_init_port(atmel_port, pdev);
>   	if (ret)
> -		goto err_clear_bit;
> +		goto err_clk_disable_unprepare;
>   
>   	atmel_port->gpios = mctrl_gpio_init(&atmel_port->uart, 0);
>   	if (IS_ERR(atmel_port->gpios)) {
>   		ret = PTR_ERR(atmel_port->gpios);
> -		goto err_clear_bit;
> +		goto err_clk_disable_unprepare;
>   	}
>   
>   	if (!atmel_use_pdc_rx(&atmel_port->uart)) {
> @@ -2912,7 +2904,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   				     sizeof(struct atmel_uart_char),
>   				     GFP_KERNEL);
>   		if (!data)
> -			goto err_alloc_ring;
> +			goto err_clk_disable_unprepare;
>   		atmel_port->rx_ring.buf = data;
>   	}
>   
> @@ -2936,12 +2928,6 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   	device_init_wakeup(&pdev->dev, 1);
>   	platform_set_drvdata(pdev, atmel_port);
>   
> -	/*
> -	 * The peripheral clock has been disabled by atmel_init_port():
> -	 * enable it before accessing I/O registers
> -	 */
> -	clk_prepare_enable(atmel_port->clk);
> -
>   	if (rs485_enabled) {
>   		atmel_uart_writel(&atmel_port->uart, ATMEL_US_MR,
>   				  ATMEL_US_USMODE_NORMAL);
> @@ -2965,12 +2951,8 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   err_add_port:
>   	kfree(atmel_port->rx_ring.buf);
>   	atmel_port->rx_ring.buf = NULL;
> -err_alloc_ring:
> -	if (!uart_console(&atmel_port->uart)) {
> -		clk_put(atmel_port->clk);
> -		atmel_port->clk = NULL;
> -	}
> -err_clear_bit:
> +err_clk_disable_unprepare:
> +	clk_disable_unprepare(atmel_port->clk);
>   	clear_bit(atmel_port->uart.line, atmel_ports_in_use);
>   err:
>   	return ret;
> @@ -3004,8 +2986,6 @@ static int atmel_serial_remove(struct platform_device *pdev)
>   
>   	clear_bit(port->line, atmel_ports_in_use);
>   
> -	clk_put(atmel_port->clk);
> -	atmel_port->clk = NULL;
>   	pdev->dev.of_node = NULL;
>   
>   	return ret;

Thanks !

[PATCH v3 3/4] tty: serial: atmel: remove enable/disable clock due to atmel_console_setup()

[Claudiu Beznea]

There is no need for clk_prepare_enable() at the beginning of
atmel_console_setup() and clk_disable_unprepare() at the end of
atmel_console_setup() as the clock is already enabled when calling
atmel_console_setup() and its disablement is done at the end
of probe.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/tty/serial/atmel_serial.c | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 4cec97fd7241..3a94c2bdda72 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2617,7 +2617,6 @@ static void __init atmel_console_get_options(struct uart_port *port, int *baud,
 
 static int __init atmel_console_setup(struct console *co, char *options)
 {
-	int ret;
 	struct uart_port *port = &atmel_ports[co->index].uart;
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 	int baud = 115200;
@@ -2630,10 +2629,6 @@ static int __init atmel_console_setup(struct console *co, char *options)
 		return -ENODEV;
 	}
 
-	ret = clk_prepare_enable(atmel_ports[co->index].clk);
-	if (ret)
-		return ret;
-
 	atmel_uart_writel(port, ATMEL_US_IDR, -1);
 	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
 	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
@@ -2914,17 +2909,6 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_add_port;
 
-#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
-	if (uart_console(&atmel_port->uart)
-			&& ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
-		/*
-		 * The serial core enabled the clock for us, so undo
-		 * the clk_prepare_enable() in atmel_console_setup()
-		 */
-		clk_disable_unprepare(atmel_port->clk);
-	}
-#endif
-
 	device_init_wakeup(&pdev->dev, 1);
 	platform_set_drvdata(pdev, atmel_port);
 
-- 
2.34.1

Re: [PATCH v3 3/4] tty: serial: atmel: remove enable/disable clock due to atmel_console_setup()

[Richard Genoud]

Le 16/06/2022 à 16:00, Claudiu Beznea a écrit :
> There is no need for clk_prepare_enable() at the beginning of
> atmel_console_setup() and clk_disable_unprepare() at the end of
> atmel_console_setup() as the clock is already enabled when calling
> atmel_console_setup() and its disablement is done at the end
> of probe.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>

> ---
>   drivers/tty/serial/atmel_serial.c | 16 ----------------
>   1 file changed, 16 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 4cec97fd7241..3a94c2bdda72 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2617,7 +2617,6 @@ static void __init atmel_console_get_options(struct uart_port *port, int *baud,
>   
>   static int __init atmel_console_setup(struct console *co, char *options)
>   {
> -	int ret;
>   	struct uart_port *port = &atmel_ports[co->index].uart;
>   	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>   	int baud = 115200;
> @@ -2630,10 +2629,6 @@ static int __init atmel_console_setup(struct console *co, char *options)
>   		return -ENODEV;
>   	}
>   
> -	ret = clk_prepare_enable(atmel_ports[co->index].clk);
> -	if (ret)
> -		return ret;
> -
>   	atmel_uart_writel(port, ATMEL_US_IDR, -1);
>   	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
>   	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
> @@ -2914,17 +2909,6 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   	if (ret)
>   		goto err_add_port;
>   
> -#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
> -	if (uart_console(&atmel_port->uart)
> -			&& ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
> -		/*
> -		 * The serial core enabled the clock for us, so undo
> -		 * the clk_prepare_enable() in atmel_console_setup()
> -		 */
> -		clk_disable_unprepare(atmel_port->clk);
> -	}
> -#endif
> -
>   	device_init_wakeup(&pdev->dev, 1);
>   	platform_set_drvdata(pdev, atmel_port);
>   
Thanks !

[PATCH v3 4/4] serial: st-asc: remove include of pm_runtime.h

[Claudiu Beznea]

st-asc driver doesn't use helpers from pm_runtime.h thus remove its
include.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
---
 drivers/tty/serial/st-asc.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index 1b0da603ab54..cce42f4c9bc2 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -17,7 +17,6 @@
 #include <linux/tty_flip.h>
 #include <linux/delay.h>
 #include <linux/spinlock.h>
-#include <linux/pm_runtime.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/serial_core.h>
-- 
2.34.1