[PATCH v7 7/7] cpufreq: dt: Add support for interconnect bandwidth scaling

Georgi Djakov
2020-04-24T15:54:34Z

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.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
v7:
* Drop using dev_pm_opp_set_paths(), as it has been removed.
* Add Kconfig dependency on INTERCONNECT, as it can be module.

v2: https://lore.kernel.org/r/20190423132823.7915-6-georgi.djakov@linaro.org

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)