diff options
| author | Maxime Ripard <maxime@cerno.tech> | 2022-10-27 15:52:43 +0300 |
|---|---|---|
| committer | Maxime Ripard <maxime@cerno.tech> | 2022-10-28 14:03:19 +0300 |
| commit | 40c31955e4e9ff268d21c0a8009e35f4cfaa167c (patch) | |
| tree | c6151e11dd3620fef12ce29984d8e4d2b7c31a80 | |
| parent | d0cde9b3b0cae06f5998f6d3936e90a80d05b2ec (diff) | |
| download | linux-40c31955e4e9ff268d21c0a8009e35f4cfaa167c.tar.xz | |
firmware: raspberrypi: Provide a helper to query a clock max rate
The firmware allows to query for its clocks the operating range of a
given clock. We'll need this for some drivers (KMS, in particular) to
infer the state of some configuration options, so let's create a
function to do so.
Acked-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220815-rpi-fix-4k-60-v5-3-fe9e7ac8b111@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
| -rw-r--r-- | drivers/firmware/raspberrypi.c | 20 | ||||
| -rw-r--r-- | include/soc/bcm2835/raspberrypi-firmware.h | 26 |
2 files changed, 46 insertions, 0 deletions
diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c index 932a8bef22fb..b15aa6fce0e9 100644 --- a/drivers/firmware/raspberrypi.c +++ b/drivers/firmware/raspberrypi.c @@ -228,6 +228,26 @@ static void rpi_register_clk_driver(struct device *dev) -1, NULL, 0); } +unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, unsigned int id) +{ + struct rpi_firmware_clk_rate_request msg = + RPI_FIRMWARE_CLK_RATE_REQUEST(id); + int ret; + + ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_MAX_CLOCK_RATE, + &msg, sizeof(msg)); + if (ret) + /* + * If our firmware doesn't support that operation, or fails, we + * assume the maximum clock rate is absolute maximum we can + * store over our type. + */ + return UINT_MAX; + + return le32_to_cpu(msg.rate); +} +EXPORT_SYMBOL_GPL(rpi_firmware_clk_get_max_rate); + static void rpi_firmware_delete(struct kref *kref) { struct rpi_firmware *fw = container_of(kref, struct rpi_firmware, diff --git a/include/soc/bcm2835/raspberrypi-firmware.h b/include/soc/bcm2835/raspberrypi-firmware.h index 9b1db12d013f..ab955591cb72 100644 --- a/include/soc/bcm2835/raspberrypi-firmware.h +++ b/include/soc/bcm2835/raspberrypi-firmware.h @@ -155,12 +155,32 @@ enum rpi_firmware_clk_id { RPI_FIRMWARE_NUM_CLK_ID, }; +/** + * struct rpi_firmware_clk_rate_request - Firmware Request for a rate + * @id: ID of the clock being queried + * @rate: Rate in Hertz. Set by the firmware. + * + * Used by @RPI_FIRMWARE_GET_CLOCK_RATE, @RPI_FIRMWARE_GET_CLOCK_MEASURED, + * @RPI_FIRMWARE_GET_MAX_CLOCK_RATE and @RPI_FIRMWARE_GET_MIN_CLOCK_RATE. + */ +struct rpi_firmware_clk_rate_request { + __le32 id; + __le32 rate; +} __packed; + +#define RPI_FIRMWARE_CLK_RATE_REQUEST(_id) \ + { \ + .id = _id, \ + } + #if IS_ENABLED(CONFIG_RASPBERRYPI_FIRMWARE) int rpi_firmware_property(struct rpi_firmware *fw, u32 tag, void *data, size_t len); int rpi_firmware_property_list(struct rpi_firmware *fw, void *data, size_t tag_size); void rpi_firmware_put(struct rpi_firmware *fw); +unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, + unsigned int id); struct device_node *rpi_firmware_find_node(void); struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node); struct rpi_firmware *devm_rpi_firmware_get(struct device *dev, @@ -180,6 +200,12 @@ static inline int rpi_firmware_property_list(struct rpi_firmware *fw, static inline void rpi_firmware_put(struct rpi_firmware *fw) { } +static inline unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, + unsigned int id) +{ + return UINT_MAX; +} + static inline struct device_node *rpi_firmware_find_node(void) { return NULL; |