Re: [PATCH v2] firmware: qcom: scm: Expose PAS command 10 as reset-controller

From: Srinivas Kandagatla
Date: Mon Jun 20 2016 - 07:20:39 EST




On 17/06/16 18:40, Bjorn Andersson wrote:
PAS command 10 is used to assert and deassert the MSS reset via
TrustZone, expose this as a reset-controller to mimic the direct
access case.

Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Good stuff!

Acked-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>


Changes since v1:
- Selecting RESET_CONTROLLER
- Constifying reset_ops

drivers/firmware/Kconfig | 1 +
drivers/firmware/qcom_scm-32.c | 13 +++++++++++++
drivers/firmware/qcom_scm-64.c | 14 ++++++++++++++
drivers/firmware/qcom_scm.c | 30 ++++++++++++++++++++++++++++++
drivers/firmware/qcom_scm.h | 2 ++
5 files changed, 60 insertions(+)

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 6664f1108c7c..5e618058defe 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -184,6 +184,7 @@ config FW_CFG_SYSFS_CMDLINE
config QCOM_SCM
bool
depends on ARM || ARM64
+ select RESET_CONTROLLER

config QCOM_SCM_32
def_bool y
diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index 3df3798729c3..cf731b3452f3 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -564,3 +564,16 @@ int __qcom_scm_pas_shutdown(u32 peripheral)

return ret ? : le32_to_cpu(out);
}
+
+int __qcom_scm_pas_mss_reset(bool reset)
+{
+ __le32 out;
+ __le32 in = cpu_to_le32(reset);
+ int ret;
+
+ ret = qcom_scm_call(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 72c2f81b8fd3..45ee872b6e6d 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -565,6 +565,20 @@ int __qcom_scm_pas_shutdown(u32 peripheral)
return ret ? : scm_ret;
}

+int __qcom_scm_pas_mss_reset(bool reset)
+{
+ struct qcom_scm_desc desc = {0};
+ int ret;
+
+ desc.args[0] = reset;
+ desc.args[1] = 0;
+ desc.arginfo = QCOM_SCM_ARGS(2);
+
+ ret = qcom_scm_call(QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_MSS_RESET, &desc);
+
+ return ret ? : desc.ret[0];
+}
+
int __qcom_scm_pil_init_image_cmd(u32 proc, u64 image_addr)
{
struct qcom_scm_desc desc = {0};
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 6fc9580a26bd..bfa9bfd9a62c 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -20,6 +20,7 @@
#include <linux/qcom_scm.h>
#include <linux/of.h>
#include <linux/clk.h>
+#include <linux/reset-controller.h>

#include "qcom_scm.h"

@@ -28,6 +29,7 @@ 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;
@@ -280,6 +282,29 @@ 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)
+{
+ if (idx != 0)
+ return -EINVAL;
+
+ return __qcom_scm_pas_mss_reset(1);
+}
+
+static int qcom_scm_pas_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long idx)
+{
+ if (idx != 0)
+ return -EINVAL;
+
+ return __qcom_scm_pas_mss_reset(0);
+}
+
+static const struct reset_control_ops qcom_scm_pas_reset_ops = {
+ .assert = qcom_scm_pas_reset_assert,
+ .deassert = qcom_scm_pas_reset_deassert,
+};
+
/**
* qcom_scm_is_available() - Checks if SCM is available
*/
@@ -322,6 +347,11 @@ static int qcom_scm_probe(struct platform_device *pdev)
return PTR_ERR(scm->bus_clk);
}

+ 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 */
rate = clk_round_rate(scm->core_clk, INT_MAX);
ret = clk_set_rate(scm->core_clk, rate);
diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index 8f1207fca771..80752cbfd139 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -44,11 +44,13 @@ extern int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
#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(u32 peripheral);
extern int __qcom_scm_pas_init_image(u32 peripheral, dma_addr_t metadata_phys);
extern int __qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size);
extern int __qcom_scm_pas_auth_and_reset(u32 peripheral);
extern int __qcom_scm_pas_shutdown(u32 peripheral);
+extern int __qcom_scm_pas_mss_reset(bool reset);

/* common error codes */
#define QCOM_SCM_ENOMEM -5