lkml.org 
[lkml]   [2014]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.14 066/158] iio: adc: at91_adc: Repair broken platform_data support
    Date
    3.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Alexandre Belloni <alexandre.belloni@free-electrons.com>

    commit 467a44b0372d8268ce5bd90e58bde7db51c1d476 upstream.

    Trying to use the at91_adc driver while not using device tree is ending up in a
    kernel crash:

    Unable to handle kernel NULL pointer dereference at virtual address 00000004
    [...]
    [<c01f3510>] (at91_adc_probe) from [<c0183828>] (platform_drv_probe+0x18/0x48)
    [<c0183828>] (platform_drv_probe) from [<c01824a4>] (driver_probe_device+0x100/0x218)
    [<c01824a4>] (driver_probe_device) from [<c0182648>] (__driver_attach+0x8c/0x90)
    [<c0182648>] (__driver_attach) from [<c0180de4>] (bus_for_each_dev+0x58/0x88)
    [<c0180de4>] (bus_for_each_dev) from [<c0181c7c>] (bus_add_driver+0xd4/0x1d4)
    [<c0181c7c>] (bus_add_driver) from [<c0182c40>] (driver_register+0x78/0xf4)
    [<c0182c40>] (driver_register) from [<c0008998>] (do_one_initcall+0xe8/0x14c)
    [<c0008998>] (do_one_initcall) from [<c02f0b50>] (kernel_init_freeable+0xec/0x1b4)
    [<c02f0b50>] (kernel_init_freeable) from [<c022acdc>] (kernel_init+0x8/0xe4)
    [<c022acdc>] (kernel_init) from [<c0009670>] (ret_from_fork+0x14/0x24)

    This is because the at91_adc_caps structure is mandatory but is not filled when
    using platform_data. Correct that by using an id_table. It ensues that the
    driver will not match "at91_adc" anymore but it was crashing anyway.

    Fixes: c46016665fff (iio: at91: ADC start-up time calculation changed since at91sam9x5)
    Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
    Tested-by: Josh Wu <josh.wu@atmel.com>
    Acked-by: Josh Wu <josh.wu@atmel.com>
    Signed-off-by: Jonathan Cameron <jic23@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/iio/adc/at91_adc.c | 26 ++++++++++++++++++++++----
    1 file changed, 22 insertions(+), 4 deletions(-)

    --- a/drivers/iio/adc/at91_adc.c
    +++ b/drivers/iio/adc/at91_adc.c
    @@ -765,14 +765,17 @@ static int at91_adc_probe_pdata(struct a
    if (!pdata)
    return -EINVAL;

    + st->caps = (struct at91_adc_caps *)
    + platform_get_device_id(pdev)->driver_data;
    +
    st->use_external = pdata->use_external_triggers;
    st->vref_mv = pdata->vref;
    st->channels_mask = pdata->channels_used;
    - st->num_channels = pdata->num_channels;
    + st->num_channels = st->caps->num_channels;
    st->startup_time = pdata->startup_time;
    st->trigger_number = pdata->trigger_number;
    st->trigger_list = pdata->trigger_list;
    - st->registers = pdata->registers;
    + st->registers = &st->caps->registers;

    return 0;
    }
    @@ -1101,7 +1104,6 @@ static int at91_adc_remove(struct platfo
    return 0;
    }

    -#ifdef CONFIG_OF
    static struct at91_adc_caps at91sam9260_caps = {
    .calc_startup_ticks = calc_startup_ticks_9260,
    .num_channels = 4,
    @@ -1154,11 +1156,27 @@ static const struct of_device_id at91_ad
    {},
    };
    MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
    -#endif
    +
    +static const struct platform_device_id at91_adc_ids[] = {
    + {
    + .name = "at91sam9260-adc",
    + .driver_data = (unsigned long)&at91sam9260_caps,
    + }, {
    + .name = "at91sam9g45-adc",
    + .driver_data = (unsigned long)&at91sam9g45_caps,
    + }, {
    + .name = "at91sam9x5-adc",
    + .driver_data = (unsigned long)&at91sam9x5_caps,
    + }, {
    + /* terminator */
    + }
    +};
    +MODULE_DEVICE_TABLE(platform, at91_adc_ids);

    static struct platform_driver at91_adc_driver = {
    .probe = at91_adc_probe,
    .remove = at91_adc_remove,
    + .id_table = at91_adc_ids,
    .driver = {
    .name = DRIVER_NAME,
    .of_match_table = of_match_ptr(at91_adc_dt_ids),



    \
     
     \ /
      Last update: 2014-05-04 19:41    [W:8.969 / U:1.500 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site