[PATCH 2/8] firmware: qcom: scm: Convert SCM to platform driver

Andy Gross
2016-04-22T22:19:51Z

This patch converts the Qualcomm SCM firmware driver into a platform
driver.

Signed-off-by: Andy Gross <andy.gross@linaro.org>
---
arch/arm64/Kconfig.platforms | 1 +
drivers/firmware/qcom_scm.c | 154 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 147 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index efa77c1..6f0876f 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -76,6 +76,7 @@ config ARCH_MVEBU
config ARCH_QCOM
bool "Qualcomm Platforms"
select PINCTRL
+ select QCOM_SCM
help
This enables support for the ARMv8 based Qualcomm chipsets.

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 45c008d..8e1eeb8 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -10,19 +10,68 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
*/
-
+#include <linux/platform_device.h>
+#include <linux/module.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 device *dev;
+ 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;
+
+ if (__scm->iface_clk) {
+ ret = clk_prepare_enable(__scm->iface_clk);
+ if (ret)
+ goto disable_core;
+ }
+
+ if (__scm->bus_clk) {
+ ret = clk_prepare_enable(__scm->bus_clk);
+ if (ret)
+ goto disable_iface;
+ }
+
+ return 0;
+
+disable_iface:
+ if (__scm->iface_clk)
+ clk_disable_unprepare(__scm->iface_clk);
+disable_core:
+ if (__scm->bus_clk)
+ clk_disable_unprepare(__scm->core_clk);
+bail:
+ return ret;
+}
+
+static void qcom_scm_clk_disable(void)
+{
+ clk_disable_unprepare(__scm->core_clk);
+ if (__scm->iface_clk)
+ clk_disable_unprepare(__scm->iface_clk);
+ if (__scm->bus_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 +121,17 @@ 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 +146,89 @@ 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_probe(struct platform_device *pdev)
+{
+ struct qcom_scm *scm;
+ long rate;
+ 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);
+ }
+
+ if (of_device_is_compatible(pdev->dev.of_node, "qcom,scm-apq8064")) {
+ 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 */
+ rate = clk_round_rate(scm->core_clk, INT_MAX);
+ ret = clk_set_rate(scm->core_clk, rate);
+ if (ret)
+ return ret;
+
+ __scm = scm;
+ __scm->dev = &pdev->dev;
+
+ return 0;
+}
+
+static const struct of_device_id qcom_scm_dt_match[] = {
+ { .compatible = "qcom,scm-apq8064",},
+ { .compatible = "qcom,scm-apq8084",},
+ { .compatible = "qcom,scm-msm8916",},
+ { .compatible = "qcom,scm-msm8974",},
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, qcom_scm_dt_match);
+
+static struct platform_driver qcom_scm_driver = {
+ .driver = {
+ .name = "qcom_scm",
+ .of_match_table = qcom_scm_dt_match,
+ },
+ .probe = qcom_scm_probe,
+};
+
+builtin_platform_driver(qcom_scm_driver);
+MODULE_DESCRIPTION("Qualcomm SCM driver");
+MODULE_LICENSE("GPL v2");
--
1.9.1