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Subject[PATCH 04/10] soundwire: bus: add PM/no-PM versions of read/write functions
Date
Add support for pm_runtime with the appropriate error checks for
sdw_write/read functions, e.g. when pm_runtime is not supported.

Also expose internal functions without pm_runtime support, which are
required to perform any sort of suspend/resume operation, as well as
any enumeration tasks.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
drivers/soundwire/bus.c | 68 +++++++++++++++++++++++++++++++----------
1 file changed, 52 insertions(+), 16 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index ea04cf5f5bdc..c525b9b50453 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -317,6 +317,46 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
return 0;
}

+/*
+ * Read/Write IO functions.
+ * no_pm versions can only be called by the bus, e.g. while enumerating or
+ * handling suspend-resume sequences.
+ * all clients need to use the pm versions
+ */
+
+static int
+sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
+{
+ struct sdw_msg msg;
+ int ret;
+
+ ret = sdw_fill_msg(&msg, slave, addr, count,
+ slave->dev_num, SDW_MSG_FLAG_READ, val);
+ if (ret < 0)
+ return ret;
+
+ return sdw_transfer(slave->bus, &msg);
+}
+
+static int
+sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
+{
+ struct sdw_msg msg;
+ int ret;
+
+ ret = sdw_fill_msg(&msg, slave, addr, count,
+ slave->dev_num, SDW_MSG_FLAG_WRITE, val);
+ if (ret < 0)
+ return ret;
+
+ return sdw_transfer(slave->bus, &msg);
+}
+
+static int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
+{
+ return sdw_nwrite_no_pm(slave, addr, 1, &value);
+}
+
/**
* sdw_nread() - Read "n" contiguous SDW Slave registers
* @slave: SDW Slave
@@ -326,19 +366,17 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
*/
int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
{
- struct sdw_msg msg;
int ret;

- ret = sdw_fill_msg(&msg, slave, addr, count,
- slave->dev_num, SDW_MSG_FLAG_READ, val);
- if (ret < 0)
- return ret;
-
ret = pm_runtime_get_sync(slave->bus->dev);
- if (ret < 0)
+ if (ret < 0 && ret != -EACCES) {
+ pm_runtime_put_noidle(slave->bus->dev);
return ret;
+ }
+
+ ret = sdw_nread_no_pm(slave, addr, count, val);

- ret = sdw_transfer(slave->bus, &msg);
+ pm_runtime_mark_last_busy(slave->bus->dev);
pm_runtime_put(slave->bus->dev);

return ret;
@@ -354,19 +392,17 @@ EXPORT_SYMBOL(sdw_nread);
*/
int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
{
- struct sdw_msg msg;
int ret;

- ret = sdw_fill_msg(&msg, slave, addr, count,
- slave->dev_num, SDW_MSG_FLAG_WRITE, val);
- if (ret < 0)
- return ret;
-
ret = pm_runtime_get_sync(slave->bus->dev);
- if (ret < 0)
+ if (ret < 0 && ret != -EACCES) {
+ pm_runtime_put_noidle(slave->bus->dev);
return ret;
+ }
+
+ ret = sdw_nwrite_no_pm(slave, addr, count, val);

- ret = sdw_transfer(slave->bus, &msg);
+ pm_runtime_mark_last_busy(slave->bus->dev);
pm_runtime_put(slave->bus->dev);

return ret;
--
2.20.1
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