[PATCH v8 07/10] cpufreq: dt: Add support for interconnect bandwidth scaling
From: Georgi Djakov <hidden>
Date: 2020-05-12 12:54:36
Also in:
linux-pm, lkml
Subsystem:
cpu frequency scaling framework, the rest · Maintainers:
"Rafael J. Wysocki", Viresh Kumar, Linus Torvalds
In addition to clocks and regulators, some devices can scale the bandwidth of their on-chip interconnect - for example between CPU and DDR memory. Add support for that, so that platforms which support it can make use of it. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Georgi Djakov <redacted> --- v8: * Picked reviewed-by tag. * Added a separate patch to check the number of paths in DT and validate each one of them. drivers/cpufreq/Kconfig | 1 + drivers/cpufreq/cpufreq-dt.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index c3e6bd59e920..db2ad54ee67f 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig@@ -217,6 +217,7 @@ config CPUFREQ_DT config CPUFREQ_DT_PLATDEV bool + depends on INTERCONNECT || !INTERCONNECT help This adds a generic DT based cpufreq platdev driver for frequency management. This creates a 'cpufreq-dt' platform device, on the
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 26fe8dfb9ce6..4ecef3257532 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c@@ -13,6 +13,7 @@ #include <linux/cpufreq.h> #include <linux/cpumask.h> #include <linux/err.h> +#include <linux/interconnect.h> #include <linux/module.h> #include <linux/of.h> #include <linux/pm_opp.h>
@@ -95,6 +96,7 @@ static int resources_available(void) struct device *cpu_dev; struct regulator *cpu_reg; struct clk *cpu_clk; + struct icc_path *cpu_path; int ret = 0; const char *name;
@@ -121,6 +123,19 @@ static int resources_available(void) clk_put(cpu_clk); + cpu_path = of_icc_get(cpu_dev, NULL); + ret = PTR_ERR_OR_ZERO(cpu_path); + if (ret) { + if (ret == -EPROBE_DEFER) + dev_dbg(cpu_dev, "defer icc path: %d\n", ret); + else + dev_err(cpu_dev, "failed to get icc path: %d\n", ret); + + return ret; + } + + icc_put(cpu_path); + name = find_supply_name(cpu_dev); /* Platform doesn't require regulator */ if (!name)