[PATCH] firmware: qcom: scm: Expose PAS command 10 as reset-controller

From: Bjorn Andersson
Date: Sat Jun 11 2016 - 00:52:41 EST


PAS command 10 is used to assert and deassert the MSS reset via
TrustZone, expose this as a reset-controller to follow the non-secure
case where GCC exposes this control.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
.../devicetree/bindings/firmware/qcom,scm.txt | 6 ++++
drivers/firmware/qcom_scm-32.c | 13 +++++++++
drivers/firmware/qcom_scm-64.c | 17 +++++++++++
drivers/firmware/qcom_scm.c | 34 ++++++++++++++++++++++
drivers/firmware/qcom_scm.h | 2 ++
5 files changed, 72 insertions(+)

diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.txt b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
index 3b4436e56865..f1ae9d3871f5 100644
--- a/Documentation/devicetree/bindings/firmware/qcom,scm.txt
+++ b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
@@ -17,6 +17,11 @@ Required properties:
- clock-names: Must contain "core" for the core clock, "iface" for the interface
clock and "bus" for the bus clock per the requirements of the compatible.

+Optional properties:
+- #reset-cells: must be 1, if specified. Specifies that the scm implements a
+ reset controller exposing the modem subsystem reset as a single reset, at
+ index 0.
+
Example for MSM8916:

firmware {
@@ -24,5 +29,6 @@ Example for MSM8916:
compatible = "qcom,scm";
clocks = <&gcc GCC_CRYPTO_CLK> , <&gcc GCC_CRYPTO_AXI_CLK>, <&gcc GCC_CRYPTO_AHB_CLK>;
clock-names = "core", "bus", "iface";
+ #reset-cells = <1>;
};
};
diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index 5e00aa400c4a..41d56013f6fc 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -513,3 +513,16 @@ int __qcom_scm_pas_shutdown(struct device *dev, u32 peripheral)

return ret ? : le32_to_cpu(out);
}
+
+int __qcom_scm_pas_mss_reset(struct device *dev, bool reset)
+{
+ __le32 out;
+ __le32 in = cpu_to_le32(reset);
+ int ret;
+
+ ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_MSS_RESET,
+ &in, sizeof(in),
+ &out, sizeof(out));
+
+ return ret ? : le32_to_cpu(out);
+}
diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index 496badd49fe8..e720100f2cb1 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -342,3 +342,20 @@ int __qcom_scm_pas_shutdown(struct device *dev, u32 peripheral)

return ret ? : scm_ret;
}
+
+int __qcom_scm_pas_mss_reset(struct device *dev, bool reset)
+{
+ struct qcom_scm_desc desc = {0};
+ u32 scm_ret;
+ int ret;
+
+ desc.args[0] = reset;
+ desc.args[1] = 0;
+ desc.arginfo = QCOM_SCM_ARGS(2);
+
+ ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_MSS_RESET,
+ &desc);
+ scm_ret = desc.res.a1;
+
+ return ret ? : scm_ret;
+}
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 79bb0b00577e..b0119535c0fb 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -21,6 +21,7 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
+#include <linux/reset-controller.h>

#include "qcom_scm.h"

@@ -29,6 +30,7 @@ struct qcom_scm {
struct clk *core_clk;
struct clk *iface_clk;
struct clk *bus_clk;
+ struct reset_controller_dev reset;
};

static struct qcom_scm *__scm;
@@ -283,6 +285,33 @@ int qcom_scm_pas_shutdown(u32 peripheral)
}
EXPORT_SYMBOL(qcom_scm_pas_shutdown);

+static int qcom_scm_pas_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long idx)
+{
+ struct qcom_scm *scm = container_of(rcdev, struct qcom_scm, reset);
+
+ if (idx != 0)
+ return -EINVAL;
+
+ return __qcom_scm_pas_mss_reset(scm->dev, 1);
+}
+
+static int qcom_scm_pas_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long idx)
+{
+ struct qcom_scm *scm = container_of(rcdev, struct qcom_scm, reset);
+
+ if (idx != 0)
+ return -EINVAL;
+
+ return __qcom_scm_pas_mss_reset(scm->dev, 0);
+}
+
+static struct reset_control_ops qcom_scm_pas_reset_ops = {
+ .assert = qcom_scm_pas_reset_assert,
+ .deassert = qcom_scm_pas_reset_deassert,
+};
+
static int qcom_scm_probe(struct platform_device *pdev)
{
struct qcom_scm *scm;
@@ -317,6 +346,11 @@ static int qcom_scm_probe(struct platform_device *pdev)
}
}

+ scm->reset.ops = &qcom_scm_pas_reset_ops;
+ scm->reset.nr_resets = 1;
+ scm->reset.of_node = pdev->dev.of_node;
+ reset_controller_register(&scm->reset);
+
/* vote for max clk rate for highest performance */
ret = clk_set_rate(scm->core_clk, INT_MAX);
if (ret)
diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index 1a16ff925d6d..3584b00fe7e6 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -46,6 +46,7 @@ extern void __qcom_scm_init(void);
#define QCOM_SCM_PAS_AUTH_AND_RESET_CMD 0x5
#define QCOM_SCM_PAS_SHUTDOWN_CMD 0x6
#define QCOM_SCM_PAS_IS_SUPPORTED_CMD 0x7
+#define QCOM_SCM_PAS_MSS_RESET 0xa
extern bool __qcom_scm_pas_supported(struct device *dev, u32 peripheral);
extern int __qcom_scm_pas_init_image(struct device *dev, u32 peripheral,
dma_addr_t metadata_phys);
@@ -53,6 +54,7 @@ extern int __qcom_scm_pas_mem_setup(struct device *dev, u32 peripheral,
phys_addr_t addr, phys_addr_t size);
extern int __qcom_scm_pas_auth_and_reset(struct device *dev, u32 peripheral);
extern int __qcom_scm_pas_shutdown(struct device *dev, u32 peripheral);
+extern int __qcom_scm_pas_mss_reset(struct device *dev, bool reset);

/* common error codes */
#define QCOM_SCM_V2_EBUSY -12
--
2.5.0