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Diffstat (limited to 'sys-kernel/boest-v5.0.15/raspberrypi/0022-clk-bcm2835-Read-max-core-clock-from-firmware.patch')
-rw-r--r--sys-kernel/boest-v5.0.15/raspberrypi/0022-clk-bcm2835-Read-max-core-clock-from-firmware.patch117
1 files changed, 117 insertions, 0 deletions
diff --git a/sys-kernel/boest-v5.0.15/raspberrypi/0022-clk-bcm2835-Read-max-core-clock-from-firmware.patch b/sys-kernel/boest-v5.0.15/raspberrypi/0022-clk-bcm2835-Read-max-core-clock-from-firmware.patch
new file mode 100644
index 00000000..78f5619d
--- /dev/null
+++ b/sys-kernel/boest-v5.0.15/raspberrypi/0022-clk-bcm2835-Read-max-core-clock-from-firmware.patch
@@ -0,0 +1,117 @@
+From 30c3caaa7f8a6475f010c44be2dc6651ba78591d Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Mon, 6 Mar 2017 09:06:18 +0000
+Subject: [PATCH 022/194] clk-bcm2835: Read max core clock from firmware
+
+The VPU is responsible for managing the core clock, usually under
+direction from the bcm2835-cpufreq driver but not via the clk-bcm2835
+driver. Since the core frequency can change without warning, it is
+safer to report the maximum clock rate to users of the core clock -
+I2C, SPI and the mini UART - to err on the safe side when calculating
+clock divisors.
+
+If the DT node for the clock driver includes a reference to the
+firmware node, use the firmware API to query the maximum core clock
+instead of reading the divider registers.
+
+Prior to this patch, a "100KHz" I2C bus was sometimes clocked at about
+160KHz. In particular, switching to the 4.9 kernel was likely to break
+SenseHAT usage on a Pi3.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ drivers/clk/bcm/clk-bcm2835.c | 39 ++++++++++++++++++++++++++++++++++-
+ 1 file changed, 38 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
+index fd381f8f43f7..e1ceafdc7dce 100644
+--- a/drivers/clk/bcm/clk-bcm2835.c
++++ b/drivers/clk/bcm/clk-bcm2835.c
+@@ -34,6 +34,7 @@
+ #include <linux/platform_device.h>
+ #include <linux/slab.h>
+ #include <dt-bindings/clock/bcm2835.h>
++#include <soc/bcm2835/raspberrypi-firmware.h>
+
+ #define CM_PASSWORD 0x5a000000
+
+@@ -288,6 +289,8 @@
+ #define LOCK_TIMEOUT_NS 100000000
+ #define BCM2835_MAX_FB_RATE 1750000000u
+
++#define VCMSG_ID_CORE_CLOCK 4
++
+ /*
+ * Names of clocks used within the driver that need to be replaced
+ * with an external parent's name. This array is in the order that
+@@ -306,6 +309,7 @@ static const char *const cprman_parent_names[] = {
+ struct bcm2835_cprman {
+ struct device *dev;
+ void __iomem *regs;
++ struct rpi_firmware *fw;
+ spinlock_t regs_lock; /* spinlock for all clocks */
+
+ /*
+@@ -988,6 +992,30 @@ static unsigned long bcm2835_clock_get_rate(struct clk_hw *hw,
+ return bcm2835_clock_rate_from_divisor(clock, parent_rate, div);
+ }
+
++static unsigned long bcm2835_clock_get_rate_vpu(struct clk_hw *hw,
++ unsigned long parent_rate)
++{
++ struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
++ struct bcm2835_cprman *cprman = clock->cprman;
++
++ if (cprman->fw) {
++ struct {
++ u32 id;
++ u32 val;
++ } packet;
++
++ packet.id = VCMSG_ID_CORE_CLOCK;
++ packet.val = 0;
++
++ if (!rpi_firmware_property(cprman->fw,
++ RPI_FIRMWARE_GET_MAX_CLOCK_RATE,
++ &packet, sizeof(packet)))
++ return packet.val;
++ }
++
++ return bcm2835_clock_get_rate(hw, parent_rate);
++}
++
+ static void bcm2835_clock_wait_busy(struct bcm2835_clock *clock)
+ {
+ struct bcm2835_cprman *cprman = clock->cprman;
+@@ -1276,7 +1304,7 @@ static int bcm2835_vpu_clock_is_on(struct clk_hw *hw)
+ */
+ static const struct clk_ops bcm2835_vpu_clock_clk_ops = {
+ .is_prepared = bcm2835_vpu_clock_is_on,
+- .recalc_rate = bcm2835_clock_get_rate,
++ .recalc_rate = bcm2835_clock_get_rate_vpu,
+ .set_rate = bcm2835_clock_set_rate,
+ .determine_rate = bcm2835_clock_determine_rate,
+ .set_parent = bcm2835_clock_set_parent,
+@@ -2155,6 +2183,7 @@ static int bcm2835_clk_probe(struct platform_device *pdev)
+ struct resource *res;
+ const struct bcm2835_clk_desc *desc;
+ const size_t asize = ARRAY_SIZE(clk_desc_array);
++ struct device_node *fw_node;
+ size_t i;
+ u32 clk_id;
+ int ret;
+@@ -2172,6 +2201,14 @@ static int bcm2835_clk_probe(struct platform_device *pdev)
+ if (IS_ERR(cprman->regs))
+ return PTR_ERR(cprman->regs);
+
++ fw_node = of_parse_phandle(dev->of_node, "firmware", 0);
++ if (fw_node) {
++ struct rpi_firmware *fw = rpi_firmware_get(NULL);
++ if (!fw)
++ return -EPROBE_DEFER;
++ cprman->fw = fw;
++ }
++
+ memset(bcm2835_clk_claimed, 0, sizeof(bcm2835_clk_claimed));
+ for (i = 0;
+ !of_property_read_u32_index(pdev->dev.of_node, "claim-clocks",