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Message-Id: <20220815-rpi-fix-4k-60-v3-3-fc56729d11fe@cerno.tech>
Date: Thu, 13 Oct 2022 11:13:10 +0200
From: Maxime Ripard <maxime@...no.tech>
To: Florian Fainelli <f.fainelli@...il.com>,
Michael Turquette <mturquette@...libre.com>,
Emma Anholt <emma@...olt.net>, Stephen Boyd <sboyd@...nel.org>,
Ray Jui <rjui@...adcom.com>,
Scott Branden <sbranden@...adcom.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@...adcom.com>,
Daniel Vetter <daniel@...ll.ch>,
David Airlie <airlied@...ux.ie>,
Maxime Ripard <mripard@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
Maxime Ripard <maxime@...no.tech>,
Stefan Wahren <stefan.wahren@...e.com>,
linux-clk@...r.kernel.org, linux-rpi-kernel@...ts.infradead.org,
Dom Cobley <popcornmix@...il.com>,
dri-devel@...ts.freedesktop.org
Subject: [PATCH v3 3/7] 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@...nel.org>
Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
drivers/firmware/raspberrypi.c | 20 ++++++++++++++++++++
include/soc/bcm2835/raspberrypi-firmware.h | 26 ++++++++++++++++++++++++++
2 files changed, 46 insertions(+)
diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
index b916e1e171f8..1353ec2f9b53 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 74c7bcc1ac2a..10248c370229 100644
--- a/include/soc/bcm2835/raspberrypi-firmware.h
+++ b/include/soc/bcm2835/raspberrypi-firmware.h
@@ -154,12 +154,32 @@ 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,
@@ -179,6 +199,12 @@ 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;
--
b4 0.11.0-dev-7da52
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