linux-kernel - Re: [PATCH 14/15] power: supply: olpc_battery: Avoid using platform

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Date:   Fri, 19 Oct 2018 16:50:16 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Lubomir Rintel <lkundrak@...sk>
Cc:     Mark Brown <broonie@...nel.org>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        quozl@...top.org, Sebastian Reichel <sre@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Eric Miao <eric.y.miao@...il.com>,
        Haojian Zhuang <haojian.zhuang@...il.com>,
        Daniel Mack <daniel@...que.org>,
        Robert Jarzmik <robert.jarzmik@...e.fr>,
        linux-spi <linux-spi@...r.kernel.org>,
        devicetree <devicetree@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-arm Mailing List <linux-arm-kernel@...ts.infradead.org>,
        Platform Driver <platform-driver-x86@...r.kernel.org>,
        devel@...verdev.osuosl.org, Linux PM <linux-pm@...r.kernel.org>
Subject: Re: [PATCH 14/15] power: supply: olpc_battery: Avoid using platform_info

On Wed, Oct 10, 2018 at 8:24 PM Lubomir Rintel <lkundrak@...sk> wrote:
>
> This wouldn't work on the DT-based ARM platform. Let's read the EC version
> directly from the EC driver instead.
>
> This makes the driver no longer x86 specific.
>
> Signed-off-by: Lubomir Rintel <lkundrak@...sk>
> ---
>  drivers/power/supply/Kconfig        |  2 +-
>  drivers/power/supply/olpc_battery.c | 35 +++++++++++++++++++++--------
>  2 files changed, 27 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index ff6dab0bf0dd..f0361e4dd457 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -151,7 +151,7 @@ config BATTERY_PMU
>
>  config BATTERY_OLPC
>         tristate "One Laptop Per Child battery"
> -       depends on X86_32 && OLPC
> +       depends on OLPC
>         help
>           Say Y to enable support for the battery on the OLPC laptop.
>
> diff --git a/drivers/power/supply/olpc_battery.c b/drivers/power/supply/olpc_battery.c
> index 2a2d7cc995f0..dde9863e5c4a 100644
> --- a/drivers/power/supply/olpc_battery.c
> +++ b/drivers/power/supply/olpc_battery.c
> @@ -20,8 +20,6 @@
>  #include <linux/sched.h>
>  #include <linux/olpc-ec.h>

>  #include <linux/of.h>

Btw, Kconfig might miss
depends on OF
part.

> -#include <asm/olpc.h>
> -
>
>  #define EC_BAT_VOLTAGE 0x10    /* uint16_t,    *9.76/32,    mV   */
>  #define EC_BAT_CURRENT 0x11    /* int16_t,     *15.625/120, mA   */
> @@ -57,6 +55,7 @@ struct olpc_battery_data {
>         struct power_supply *olpc_ac;
>         struct power_supply *olpc_bat;
>         char bat_serial[17];
> +       int new_proto;
>  };
>
>  /*********************************************************************
> @@ -100,7 +99,7 @@ static const struct power_supply_desc olpc_ac_desc = {
>  static int olpc_bat_get_status(struct olpc_battery_data *data,
>                 union power_supply_propval *val, uint8_t ec_byte)
>  {
> -       if (olpc_platform_info.ecver > 0x44) {
> +       if (data->new_proto) {
>                 if (ec_byte & (BAT_STAT_CHARGING | BAT_STAT_TRICKLE))
>                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
>                 else if (ec_byte & BAT_STAT_DISCHARGING)
> @@ -608,14 +607,32 @@ static int olpc_battery_probe(struct platform_device *pdev)
>         struct power_supply_config psy_cfg = {};
>         struct olpc_battery_data *data;
>         uint8_t status;

> +       unsigned char ecver[1];

isn't it simple
 uint8_t ecver;
?

> +       int ret;
> +
> +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +       if (!data)
> +               return -ENOMEM;
> +       platform_set_drvdata(pdev, data);
> +
> +       /* See if the EC is already there and get the EC revision */
> +       ret = olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, ecver, ARRAY_SIZE(ecver));

> +       if (ret) {

> +               if (ret == -ENODEV)
> +                       return -EPROBE_DEFER;

Yeah, exactly a question I asked somewhere in the first part of the series.

> +               return ret;
> +       }
>
> -       /*
> -        * We've seen a number of EC protocol changes; this driver requires
> -        * the latest EC protocol, supported by 0x44 and above.
> -        */
> -       if (olpc_platform_info.ecver < 0x44) {
> +       if (ecver[0] > 0x44) {
> +               /* XO 1 or 1.5 with a new EC firmware. */
> +               data->new_proto = 1;
> +       } else if (ecver[0] < 0x44) {
> +               /*
> +                * We've seen a number of EC protocol changes; this driver
> +                * requires the latest EC protocol, supported by 0x44 and above.
> +                */
>                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
> -                       "battery driver.\n", olpc_platform_info.ecver);
> +                       "battery driver.\n", ecver[0]);
>                 return -ENXIO;
>         }
>
> --
> 2.19.0
>


-- 
With Best Regards,
Andy Shevchenko