Hi Joel,
On Fri, 2017-05-26 at 11:55 +1000, Joel Stanley wrote:
> This adds the hooks for an optional reset controller in the 8250 device
> tree node.
>
> Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
>
> ---
> v2:
> Address Philipp's comments. Thanks for the review!
> - use _shared variant
> - remove unnecessary error handling
>
> Documentation/devicetree/bindings/serial/8250.txt | 1 +
> drivers/tty/serial/8250/8250_of.c | 10 ++++++++++
> 2 files changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
> index 10276a46ecef..63e32393f82b 100644
> --- a/Documentation/devicetree/bindings/serial/8250.txt
> +++ b/Documentation/devicetree/bindings/serial/8250.txt
> @@ -45,6 +45,7 @@ Optional properties:
> property.
> - tx-threshold: Specify the TX FIFO low water indication for parts with
> programmable TX FIFO thresholds.
> +- resets : phandle + reset specifier pairs
>
> Note:
> * fsl,ns16550:
> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
> index 1cbadafc6889..e95cc9698c32 100644
> --- a/drivers/tty/serial/8250/8250_of.c
> +++ b/drivers/tty/serial/8250/8250_of.c
> @@ -19,11 +19,13 @@
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/clk.h>
> +#include <linux/reset.h>
>
> #include "8250.h"
>
> struct of_serial_info {
> struct clk *clk;
> + struct reset_control *rst;
> int type;
> int line;
> };
> @@ -132,6 +134,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
> }
> }
>
> + info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
> + if (IS_ERR(info->rst))
> + goto out;
> + ret = reset_control_deassert(info->rst);
> + if (ret)
> + goto out;
> +
> port->type = type;
> port->uartclk = clk;
> port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
> @@ -231,6 +240,7 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
>
> if (info->clk)
> clk_disable_unprepare(info->clk);
> + reset_control_assert(info->rst);
The clock is enabled before the reset is deasserted in
of_platform_serial_setup, I'd disable it after asserting the reset in
of_platform_serial_remove. Other than that,
Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
regards
Philipp
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