[PATCH] pinctrl: fsl: imx: Check for 0 config register
Stefan Agner
stefan at agner.ch
Fri Mar 27 03:32:31 PDT 2015
On 2015-03-24 16:26, Markus Pargmann wrote:
> 0 is used in all pinfunction definitions when a config register is not
> available, for example imx25-pinfunc.h. If a configuration value is used
> for such a pinfunction the driver will always write it to the
> configuration register if it is not -1. For a 0 configuration register
> the configuration value is written to offset 0x0. This can lead to a
> crashing/hanging system without any warning message.
0 is a valid offset for Vybrid's mux register, however, since Vybrid set
the SHARE_MUX_CONF_REG, intepreting a 0 in conf_reg as "not set"
actually works.
What is a bit a bummer is that we now have different meanings of 0,
depending on the field:
- For the first field (mux), 0 is a valid offset
- For the second field (config), 0 means not valid
However, I can't think of a easy solution which would solve this in a
cleaner mannor... Maybe a comment in the function header how the 5 u32's
are intepreted would appropriate?
--
Stefan
>
> This patch checks for 0 config register and sets the internal value to
> -1. If the configuration value is not NO_PADCTL this leads to an error
> message that applying the configuration failed.
>
> Signed-off-by: Markus Pargmann <mpa at pengutronix.de>
> ---
> drivers/pinctrl/freescale/pinctrl-imx.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c
> b/drivers/pinctrl/freescale/pinctrl-imx.c
> index 448f10986c28..2cc400b0a26b 100644
> --- a/drivers/pinctrl/freescale/pinctrl-imx.c
> +++ b/drivers/pinctrl/freescale/pinctrl-imx.c
> @@ -542,10 +542,13 @@ static int imx_pinctrl_parse_groups(struct
> device_node *np,
> struct imx_pin_reg *pin_reg;
> struct imx_pin *pin = &grp->pins[i];
>
> - if (info->flags & SHARE_MUX_CONF_REG)
> + if (info->flags & SHARE_MUX_CONF_REG) {
> conf_reg = mux_reg;
> - else
> + } else {
> conf_reg = be32_to_cpu(*list++);
> + if (!conf_reg)
> + conf_reg = -1;
> + }
>
> pin_id = mux_reg ? mux_reg / 4 : conf_reg / 4;
> pin_reg = &info->pin_regs[pin_id];
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