git.openwrt.org Git - openwrt/staging/svanheule.git/blob

   1 From 4c64053e0646f66463bded712d7e6975757cf4c2 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Tue, 20 Sep 2022 13:49:10 +0200
   4 Subject: [PATCH] firmware: raspberrypi: Provide a helper to query a
   5  clock max rate
   6
   7 The firmware allows to query for its clocks the operating range of a
   8 given clock. We'll need this for some drivers (KMS, in particular) to
   9 infer the state of some configuration options, so let's create a
  10 function to do so.
  11
  12 Acked-by: Stephen Boyd <sboyd@kernel.org>
  13 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  14 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  15 ---
  16  drivers/firmware/raspberrypi.c             | 20 +++++++++++++++++
  17  include/soc/bcm2835/raspberrypi-firmware.h | 26 ++++++++++++++++++++++
  18  2 files changed, 46 insertions(+)
  19
  20 --- a/drivers/firmware/raspberrypi.c
  21 +++ b/drivers/firmware/raspberrypi.c
  22 @@ -342,6 +342,26 @@ static void rpi_register_clk_driver(stru
  23                                                 -1, NULL, 0);
  24  }
  25
  26 +unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, unsigned int id)
  27 +{
  28 +       struct rpi_firmware_clk_rate_request msg =
  29 +               RPI_FIRMWARE_CLK_RATE_REQUEST(id);
  30 +       int ret;
  31 +
  32 +       ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_MAX_CLOCK_RATE,
  33 +                                   &msg, sizeof(msg));
  34 +       if (ret)
  35 +               /*
  36 +                * If our firmware doesn't support that operation, or fails, we
  37 +                * assume the maximum clock rate is absolute maximum we can
  38 +                * store over our type.
  39 +                */
  40 +                return UINT_MAX;
  41 +
  42 +       return le32_to_cpu(msg.rate);
  43 +}
  44 +EXPORT_SYMBOL_GPL(rpi_firmware_clk_get_max_rate);
  45 +
  46  static void rpi_firmware_delete(struct kref *kref)
  47  {
  48         struct rpi_firmware *fw = container_of(kref, struct rpi_firmware,
  49 --- a/include/soc/bcm2835/raspberrypi-firmware.h
  50 +++ b/include/soc/bcm2835/raspberrypi-firmware.h
  51 @@ -181,12 +181,32 @@ enum rpi_firmware_clk_id {
  52
  53  #define GET_DISPLAY_SETTINGS_PAYLOAD_SIZE 64
  54
  55 +/**
  56 + * struct rpi_firmware_clk_rate_request - Firmware Request for a rate
  57 + * @id:        ID of the clock being queried
  58 + * @rate: Rate in Hertz. Set by the firmware.
  59 + *
  60 + * Used by @RPI_FIRMWARE_GET_CLOCK_RATE, @RPI_FIRMWARE_GET_CLOCK_MEASURED,
  61 + * @RPI_FIRMWARE_GET_MAX_CLOCK_RATE and @RPI_FIRMWARE_GET_MIN_CLOCK_RATE.
  62 + */
  63 +struct rpi_firmware_clk_rate_request {
  64 +       __le32 id;
  65 +       __le32 rate;
  66 +} __packed;
  67 +
  68 +#define RPI_FIRMWARE_CLK_RATE_REQUEST(_id)     \
  69 +       {                                       \
  70 +               .id = _id,                      \
  71 +       }
  72 +
  73  #if IS_ENABLED(CONFIG_RASPBERRYPI_FIRMWARE)
  74  int rpi_firmware_property(struct rpi_firmware *fw,
  75                           u32 tag, void *data, size_t len);
  76  int rpi_firmware_property_list(struct rpi_firmware *fw,
  77                                void *data, size_t tag_size);
  78  void rpi_firmware_put(struct rpi_firmware *fw);
  79 +unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw,
  80 +                                          unsigned int id);
  81  struct device_node *rpi_firmware_find_node(void);
  82  struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node);
  83  struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
  84 @@ -206,6 +226,12 @@ static inline int rpi_firmware_property_
  85
  86  static inline void rpi_firmware_put(struct rpi_firmware *fw) { }
  87
  88 +static inline unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw,
  89 +                                                        unsigned int id)
  90 +{
  91 +       return UINT_MAX;
  92 +}
  93 +
  94  static inline struct device_node *rpi_firmware_find_node(void)
  95  {
  96         return NULL;