This patch creates a platform driver for the SCM so that we can adequately
manage resources. This removes clients having to carry the necessary
clocks to use the SCM resources.
Signed-off-by: Andy Gross <agross@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/firmware/qcom,scm.txt | 25 ++++
drivers/firmware/qcom_scm.c | 138 +++++++++++++++++++-
2 files changed, 159 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/firmware/qcom,scm.txt
diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.txt b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
new file mode 100644
index 0000000..debcd32
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
@@ -0,0 +1,25 @@
+QCOM Secure Channel Manager (SCM)
+
+Qualcomm processors include an interface to communicate to the secure firmware.
+This interface allows for clients to request different types of actions. These
+can include CPU power up/down, HDCP requests, loading of firmware, and other
+assorted actions.
+
+Required properties:
+- compatible: must contain "qcom,scm"
+- clocks: Should contain the core, iface, and bus clocks.
+- clock-names: Must contain "core" for the core clock, "iface" for the interface
+ clock and "bus" for the bus clock.
+
+Example:
+
+ firmware {
+ compatible = "simple-bus";
+
+ scm {
+ compatible = "qcom,scm";
+ clocks = <&gcc GCC_CE1_CLK> , <&gcc GCC_CE1_AXI_CLK>, <&gcc GCC_CE1_AHB_CLK>;
+ clock-names = "core", "bus", "iface";
+ };
+ };
+
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 45c008d..5dd0514 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -15,14 +15,57 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
-
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/qcom_scm.h>
+#include <linux/of.h>
+#include <linux/clk.h>
#include "qcom_scm.h"
+struct qcom_scm {
+ struct clk *core_clk;
+ struct clk *iface_clk;
+ struct clk *bus_clk;
+};
+
+static struct qcom_scm *__scm;
+
+static int qcom_scm_clk_enable(void)
+{
+ int ret;
+
+ ret = clk_prepare_enable(__scm->core_clk);
+ if (ret)
+ goto bail;
+ ret = clk_prepare_enable(__scm->iface_clk);
+ if (ret)
+ goto disable_core;
+ ret = clk_prepare_enable(__scm->bus_clk);
+ if (ret)
+ goto disable_iface;
+
+ return 0;
+
+disable_iface:
+ clk_disable_unprepare(__scm->iface_clk);
+disable_core:
+ clk_disable_unprepare(__scm->core_clk);
+bail:
+ return ret;
+}
+
+static void qcom_scm_clk_disable(void)
+{
+ clk_disable_unprepare(__scm->core_clk);
+ clk_disable_unprepare(__scm->iface_clk);
+ clk_disable_unprepare(__scm->bus_clk);
+}
+
/**
* qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
* @entry: Entry point function for the cpus
@@ -72,11 +115,17 @@ EXPORT_SYMBOL(qcom_scm_cpu_power_down);
*/
bool qcom_scm_hdcp_available(void)
{
- int ret;
+ int ret = qcom_scm_clk_enable();
+
+ if (ret)
+ goto clk_err;
ret = __qcom_scm_is_call_available(QCOM_SCM_SVC_HDCP,
- QCOM_SCM_CMD_HDCP);
+ QCOM_SCM_CMD_HDCP);
+
+ qcom_scm_clk_disable();
+clk_err:
return (ret > 0) ? true : false;
}
EXPORT_SYMBOL(qcom_scm_hdcp_available);
@@ -91,6 +140,87 @@ EXPORT_SYMBOL(qcom_scm_hdcp_available);
*/
int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
{
- return __qcom_scm_hdcp_req(req, req_cnt, resp);
+ int ret = qcom_scm_clk_enable();
+
+ if (ret)
+ return ret;
+
+ ret = __qcom_scm_hdcp_req(req, req_cnt, resp);
+ qcom_scm_clk_disable();
+ return ret;
}
EXPORT_SYMBOL(qcom_scm_hdcp_req);
+
+/**
+ * qcom_scm_is_available() - Checks if SCM is available
+ */
+bool qcom_scm_is_available(void)
+{
+ return !!__scm;
+}
+EXPORT_SYMBOL(qcom_scm_is_available);
+
+static int qcom_scm_remove(struct platform_device *pdev)
+{
+ __scm = NULL;
+
+ return 0;
+}
+
+static int qcom_scm_probe(struct platform_device *pdev)
+{
+ struct qcom_scm *scm;
+ int ret;
+
+ scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL);
+ if (!scm)
+ return -ENOMEM;
+
+ scm->core_clk = devm_clk_get(&pdev->dev, "core");
+ if (IS_ERR(scm->core_clk)) {
+ if (PTR_ERR(scm->core_clk) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "failed to acquire core clk\n");
+ return PTR_ERR(scm->core_clk);
+ }
+
+ scm->iface_clk = devm_clk_get(&pdev->dev, "iface");
+ if (IS_ERR(scm->iface_clk)) {
+ if (PTR_ERR(scm->iface_clk) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "failed to acquire iface clk\n");
+ return PTR_ERR(scm->iface_clk);
+ }
+
+ scm->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ if (IS_ERR(scm->bus_clk)) {
+ if (PTR_ERR(scm->bus_clk) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "failed to acquire bus clk\n");
+ return PTR_ERR(scm->bus_clk);
+ }
+
+ /* vote for max clk rate for highest performance */
+ ret = clk_set_rate(scm->core_clk, INT_MAX);
+ if (ret)
+ return ret;
+
+ __scm = scm;
+
+ return 0;
+}
+
+static const struct of_device_id qcom_scm_dt_match[] = {
+ { .compatible = "qcom,scm",},
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, qcom_scm_dt_match);
+
+static struct platform_driver qcom_scm_driver = {
+ .driver = {
+ .name = "scm",
+ .of_match_table = qcom_scm_dt_match,
+ },
+ .probe = qcom_scm_probe,
+ .remove = qcom_scm_remove,
+};
+
+module_platform_driver(qcom_scm_driver);
--
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