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Message-ID: <51C2B3D1.9060601@atmel.com>
Date: Thu, 20 Jun 2013 09:48:33 +0200
From: Nicolas Ferre <nicolas.ferre@...el.com>
To: Boris BREZILLON <b.brezillon@...rkiz.com>
CC: Ludovic Desroches <ludovic.desroches@...el.com>,
"Jean-Christophe Plagniol-Villard" <plagnioj@...osoft.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Jiri Slaby <jslaby@...e.cz>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <linux-serial@...r.kernel.org>
Subject: Re: [PATCH 4/8] tty: atmel_serial: prepare clk before calling enable
On 19/06/2013 13:17, Boris BREZILLON :
> Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
> avoid common clk framework warnings.
>
> Signed-off-by: Boris BREZILLON <b.brezillon@...rkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@...el.com>
(one comment though)
> ---
> drivers/tty/serial/atmel_serial.c | 41 ++++++++++++++++++++++++++++---------
> 1 file changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 3467462..691265f 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -1100,7 +1100,7 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state,
> * Enable the peripheral clock for this serial port.
> * This is called on uart_open() or a resume event.
> */
> - clk_enable(atmel_port->clk);
> + clk_prepare_enable(atmel_port->clk);
Do we need to check return code here?
>
> /* re-enable interrupts if we disabled some on suspend */
> UART_PUT_IER(port, atmel_port->backup_imr);
> @@ -1114,7 +1114,7 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state,
> * Disable the peripheral clock for this serial port.
> * This is called on uart_close() or a suspend event.
> */
> - clk_disable(atmel_port->clk);
> + clk_disable_unprepare(atmel_port->clk);
> break;
> default:
> printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
> @@ -1458,9 +1458,10 @@ static void atmel_of_init_port(struct atmel_uart_port *atmel_port,
> /*
> * Configure the port from the platform device resource info.
> */
> -static void atmel_init_port(struct atmel_uart_port *atmel_port,
> +static int atmel_init_port(struct atmel_uart_port *atmel_port,
> struct platform_device *pdev)
> {
> + int ret;
> struct uart_port *port = &atmel_port->uart;
> struct atmel_uart_data *pdata = pdev->dev.platform_data;
>
> @@ -1496,9 +1497,19 @@ static void atmel_init_port(struct atmel_uart_port *atmel_port,
> /* for console, the clock could already be configured */
> if (!atmel_port->clk) {
> atmel_port->clk = clk_get(&pdev->dev, "usart");
> - clk_enable(atmel_port->clk);
> + 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(atmel_port->clk);
> + clk_disable_unprepare(atmel_port->clk);
> /* only enable clock when USART is in use */
> }
>
> @@ -1511,6 +1522,8 @@ static void atmel_init_port(struct atmel_uart_port *atmel_port,
> } else {
> atmel_port->tx_done_mask = ATMEL_US_TXRDY;
> }
> +
> + return 0;
> }
>
> struct platform_device *atmel_default_console_device; /* the serial console device */
> @@ -1601,6 +1614,7 @@ 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;
> int baud = 115200;
> int bits = 8;
> @@ -1612,7 +1626,9 @@ static int __init atmel_console_setup(struct console *co, char *options)
> return -ENODEV;
> }
>
> - clk_enable(atmel_ports[co->index].clk);
> + ret = clk_prepare_enable(atmel_ports[co->index].clk);
> + if (ret)
> + return ret;
>
> UART_PUT_IDR(port, -1);
> UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
> @@ -1645,6 +1661,7 @@ static struct console atmel_console = {
> */
> static int __init atmel_console_init(void)
> {
> + int ret;
> if (atmel_default_console_device) {
> struct atmel_uart_data *pdata =
> atmel_default_console_device->dev.platform_data;
> @@ -1655,7 +1672,9 @@ static int __init atmel_console_init(void)
> port->uart.line = id;
>
> add_preferred_console(ATMEL_DEVICENAME, id, NULL);
> - atmel_init_port(port, atmel_default_console_device);
> + ret = atmel_init_port(port, atmel_default_console_device);
> + if (ret)
> + return ret;
> register_console(&atmel_console);
> }
>
> @@ -1786,7 +1805,9 @@ static int atmel_serial_probe(struct platform_device *pdev)
> port->backup_imr = 0;
> port->uart.line = ret;
>
> - atmel_init_port(port, pdev);
> + ret = atmel_init_port(port, pdev);
> + if (ret)
> + goto err;
>
> pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
> if (IS_ERR(pinctrl)) {
> @@ -1812,9 +1833,9 @@ static int atmel_serial_probe(struct platform_device *pdev)
> && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
> /*
> * The serial core enabled the clock for us, so undo
> - * the clk_enable() in atmel_console_setup()
> + * the clk_prepare_enable() in atmel_console_setup()
> */
> - clk_disable(port->clk);
> + clk_disable_unprepare(port->clk);
> }
> #endif
>
>
--
Nicolas Ferre
--
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