| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <e540bf3c-c689-10fb-984a-c2458000cab7@baylibre.com>
Date: Mon, 12 Jun 2017 14:48:00 +0200
From: Neil Armstrong <narmstrong@...libre.com>
To: Jerome Brunet <jbrunet@...libre.com>, gregkh@...uxfoundation.org,
khilman@...libre.com
Cc: linux-kernel@...r.kernel.org, Helmut Klein <hgkr.klein@...il.com>,
linux-serial@...r.kernel.org, linux-amlogic@...ts.infradead.org,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v4 2/7] tty/serial: meson_uart: update to stable bindings
On 06/12/2017 11:39 AM, Jerome Brunet wrote:
> On Fri, 2017-06-09 at 11:49 +0200, Neil Armstrong wrote:
>> From: Helmut Klein <hgkr.klein@...il.com>
>>
>> This patch handle the stable UART bindings but also keeps compatibility
>> with the legacy non-stable bindings until all boards uses them.
>>
>> Signed-off-by: Helmut Klein <hgkr.klein@...il.com>
>> Signed-off-by: Neil Armstrong <narmstrong@...libre.com>
>> ---
>> drivers/tty/serial/meson_uart.c | 109 +++++++++++++++++++++++++++++++++++++
>> ---
>> 1 file changed, 103 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
>> index 60f1679..d2c8136 100644
>> --- a/drivers/tty/serial/meson_uart.c
>> +++ b/drivers/tty/serial/meson_uart.c
>> @@ -579,8 +579,12 @@ static void meson_serial_early_console_write(struct
>> console *co,
>> device->con->write = meson_serial_early_console_write;
>> return 0;
>> }
>> +/* Legacy bindings, should be removed when no more used */
>> OF_EARLYCON_DECLARE(meson, "amlogic,meson-uart",
>> meson_serial_early_console_setup);
>> +/* Stable bindings */
>> +OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart",
>> + meson_serial_early_console_setup);
>>
>> #define MESON_SERIAL_CONSOLE (&meson_serial_console)
>> #else
>> @@ -595,11 +599,95 @@ static void meson_serial_early_console_write(struct
>> console *co,
>> .cons = MESON_SERIAL_CONSOLE,
>> };
>>
>> +/*
>> + * This function gets clocks in the legacy non-stable DT bindings.
>> + * This code will be remove once all the platforms switch to the
>> + * new DT bindings.
>> + */
>> +static int meson_uart_probe_clocks_legacy(struct platform_device *pdev,
>> + struct uart_port *port)
>> +{
>> + struct clk *clk = NULL;
>> + int ret;
>> +
>> + clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(clk))
>> + return PTR_ERR(clk);
>> +
>> + ret = clk_prepare_enable(clk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "couldn't enable clk\n");
>> + return ret;
>> + }
>> +
>> + devm_add_action_or_reset(&pdev->dev,
>> + (void(*)(void *))clk_disable_unprepare,
>> + clk);
>> +
>> + port->uartclk = clk_get_rate(clk);
>> +
>> + return 0;
>> +}
>> +
>> +static int meson_uart_probe_clocks(struct platform_device *pdev,
>> + struct uart_port *port)
>> +{
>> + struct clk *clk_xtal = NULL;
>> + struct clk *clk_pclk = NULL;
>> + struct clk *clk_baud = NULL;
>> + int ret;
>> +
>> + clk_pclk = devm_clk_get(&pdev->dev, "pclk");
>> + if (IS_ERR(clk_pclk))
>> + return PTR_ERR(clk_pclk);
>> +
>> + clk_xtal = devm_clk_get(&pdev->dev, "xtal");
>> + if (IS_ERR(clk_xtal))
>> + return PTR_ERR(clk_xtal);
>> +
>> + clk_baud = devm_clk_get(&pdev->dev, "baud");
>> + if (IS_ERR(clk_xtal))
>> + return PTR_ERR(clk_baud);
>> +
>> + ret = clk_prepare_enable(clk_pclk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "couldn't enable pclk\n");
>> + return ret;
>> + }
>> +
>> + devm_add_action_or_reset(&pdev->dev,
>> + (void(*)(void *))clk_disable_unprepare,
>> + clk_pclk);
>> +
>> + ret = clk_prepare_enable(clk_xtal);
>> + if (ret) {
>> + dev_err(&pdev->dev, "couldn't enable xtal\n");
>> + return ret;
>> + }
>> +
>> + devm_add_action_or_reset(&pdev->dev,
>> + (void(*)(void *))clk_disable_unprepare,
>> + clk_xtal);
>> +
>> + ret = clk_prepare_enable(clk_baud);
>> + if (ret) {
>> + dev_err(&pdev->dev, "couldn't enable baud clk\n");
>> + return ret;
>> + }
>> +
>> + devm_add_action_or_reset(&pdev->dev,
>> + (void(*)(void *))clk_disable_unprepare,
>> + clk_baud);
>
> It's not critical but there is a lot of duplication here. Should we add an
> helper function doing "get, prepare_enable, add_reset_action" with the clock
> name as argument ?
Yep, will do.
>
> Apart from this:
>
> Reviewed-by: Jerome Brunet <jbrunet@...libre.com>
>
>> +
>> + port->uartclk = clk_get_rate(clk_baud);
>
> This was already like this, but I wonder if we should store the *clk instead of
> caching the rate. Then call get_rate when appropriate
>
> Could be done in separate patch.
Well, this is the limit of the TTY framework, I'll leave it like this until we find
a good way to pass a context structure with the proper baud clock pointer and
don't rely anymore on the tty structure for this.
>
>> +
>> + return 0;
>> +}
>> +
>> static int meson_uart_probe(struct platform_device *pdev)
>> {
>> struct resource *res_mem, *res_irq;
>> struct uart_port *port;
>> - struct clk *clk;
>> int ret = 0;
>>
>> if (pdev->dev.of_node)
>> @@ -625,11 +713,15 @@ static int meson_uart_probe(struct platform_device
>> *pdev)
>> if (!port)
>> return -ENOMEM;
>>
>> - clk = clk_get(&pdev->dev, NULL);
>> - if (IS_ERR(clk))
>> - return PTR_ERR(clk);
>> + /* Use legacy way until all platforms switch to new bindings */
>> + if (of_device_is_compatible(pdev->dev.of_node, "amlogic,meson-uart"))
>> + ret = meson_uart_probe_clocks_legacy(pdev, port);
>> + else
>> + ret = meson_uart_probe_clocks(pdev, port);
>> +
>> + if (ret)
>> + return ret;
>>
>> - port->uartclk = clk_get_rate(clk);
>> port->iotype = UPIO_MEM;
>> port->mapbase = res_mem->start;
>> port->irq = res_irq->start;
>> @@ -668,9 +760,14 @@ static int meson_uart_remove(struct platform_device
>> *pdev)
>> return 0;
>> }
>>
>> -
>> static const struct of_device_id meson_uart_dt_match[] = {
>> + /* Legacy bindings, should be removed when no more used */
>> { .compatible = "amlogic,meson-uart" },
>> + /* Stable bindings */
>> + { .compatible = "amlogic,meson6-uart" },
>> + { .compatible = "amlogic,meson8-uart" },
>> + { .compatible = "amlogic,meson8b-uart" },
>> + { .compatible = "amlogic,meson-gx-uart" },
>> { /* sentinel */ },
>> };
>> MODULE_DEVICE_TABLE(of, meson_uart_dt_match);
>
Thanks,
Neil
Powered by blists - more mailing lists