[PATCH 1/3] spi: spi-mem: add automatic poll status functions

patrice.chotard
2021-04-26T14:40:04Z

From: Christophe Kerello <christophe.kerello@foss.st.com>

With STM32 QSPI, it is possible to poll the status register of the device.
This could be done to offload the CPU during an operation (erase or
program a SPI NAND for example).

spi_mem_poll_status API has been added to handle this feature.

Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
---
drivers/spi/spi-mem.c | 34 ++++++++++++++++++++++++++++++++++
include/linux/spi/spi-mem.h | 8 ++++++++
2 files changed, 42 insertions(+)

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 1513553e4080..43dce4b0efa4 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -743,6 +743,40 @@ static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
return container_of(drv, struct spi_mem_driver, spidrv.driver);
}

+/**
+ * spi_mem_poll_status() - Poll memory device status
+ * @mem: SPI memory device
+ * @op: the memory operation to execute
+ * @mask: status bitmask to ckeck
+ * @match: status expected value
+ * @timeout: timeout
+ *
+ * This function send a polling status request to the controller driver
+ *
+ * Return: 0 in case of success, -ETIMEDOUT in case of error,
+ * -EOPNOTSUPP if not supported.
+ */
+int spi_mem_poll_status(struct spi_mem *mem,
+ const struct spi_mem_op *op,
+ u8 mask, u8 match, u16 timeout)
+{
+ struct spi_controller *ctlr = mem->spi->controller;
+ int ret = -EOPNOTSUPP;
+
+ if (ctlr->mem_ops && ctlr->mem_ops->poll_status) {
+ ret = spi_mem_access_start(mem);
+ if (ret)
+ return ret;
+
+ ret = ctlr->mem_ops->poll_status(mem, op, mask, match, timeout);
+
+ spi_mem_access_end(mem);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_mem_poll_status);
+
static int spi_mem_probe(struct spi_device *spi)
{
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
index 2b65c9edc34e..5f78917c0f68 100644
--- a/include/linux/spi/spi-mem.h
+++ b/include/linux/spi/spi-mem.h
@@ -250,6 +250,7 @@ static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
* the currently mapped area), and the caller of
* spi_mem_dirmap_write() is responsible for calling it again in
* this case.
+ * @poll_status: poll memory device status
*
* This interface should be implemented by SPI controllers providing an
* high-level interface to execute SPI memory operation, which is usually the
@@ -274,6 +275,9 @@ struct spi_controller_mem_ops {
u64 offs, size_t len, void *buf);
ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, const void *buf);
+ int (*poll_status)(struct spi_mem *mem,
+ const struct spi_mem_op *op,
+ u8 mask, u8 match, u16 timeout);
};

/**
@@ -369,6 +373,10 @@ devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
void devm_spi_mem_dirmap_destroy(struct device *dev,
struct spi_mem_dirmap_desc *desc);

+int spi_mem_poll_status(struct spi_mem *mem,
+ const struct spi_mem_op *op,
+ u8 mask, u8 match, u16 timeout);
+
int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
struct module *owner);

--
2.17.1