lkml.org 
[lkml]   [2023]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH V6 3/6] drm: bridge: samsung-dsim: Fetch pll-clock-frequency automatically
    Date
    Make the pll-clock-frequency optional.  If it's present, use it
    to maintain backwards compatibility with existing hardware. If it
    is absent, read clock rate of "sclk_mipi" to determine the rate.
    Since it can be optional, change the message from an error to
    dev_info.

    Signed-off-by: Adam Ford <aford173@gmail.com>
    Tested-by: Chen-Yu Tsai <wenst@chromium.org>
    Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
    Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
    ---
    drivers/gpu/drm/bridge/samsung-dsim.c | 23 ++++++++++++++++-------
    1 file changed, 16 insertions(+), 7 deletions(-)

    diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
    index bf4b33d2de76..08266303c261 100644
    --- a/drivers/gpu/drm/bridge/samsung-dsim.c
    +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
    @@ -1712,11 +1712,11 @@ static const struct mipi_dsi_host_ops samsung_dsim_ops = {
    };

    static int samsung_dsim_of_read_u32(const struct device_node *np,
    - const char *propname, u32 *out_value)
    + const char *propname, u32 *out_value, bool optional)
    {
    int ret = of_property_read_u32(np, propname, out_value);

    - if (ret < 0)
    + if (ret < 0 && !optional)
    pr_err("%pOF: failed to get '%s' property\n", np, propname);

    return ret;
    @@ -1726,20 +1726,29 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi)
    {
    struct device *dev = dsi->dev;
    struct device_node *node = dev->of_node;
    + struct clk *pll_clk;
    int ret;

    ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency",
    - &dsi->pll_clk_rate);
    - if (ret < 0)
    - return ret;
    + &dsi->pll_clk_rate, 1);
    +
    + /* If it doesn't exist, read it from the clock instead of failing */
    + if (ret < 0) {
    + dev_info(dev, "Using sclk_mipi for pll clock frequency\n");
    + pll_clk = devm_clk_get(dev, "sclk_mipi");
    + if (!IS_ERR(pll_clk))
    + dsi->pll_clk_rate = clk_get_rate(pll_clk);
    + else
    + return PTR_ERR(pll_clk);
    + }

    ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency",
    - &dsi->burst_clk_rate);
    + &dsi->burst_clk_rate, 0);
    if (ret < 0)
    return ret;

    ret = samsung_dsim_of_read_u32(node, "samsung,esc-clock-frequency",
    - &dsi->esc_clk_rate);
    + &dsi->esc_clk_rate, 0);
    if (ret < 0)
    return ret;

    --
    2.39.2
    \
     
     \ /
      Last update: 2023-05-16 01:58    [W:5.793 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site