[PATCH v2 3/4] spi: dw: Add basic runtime PM support

Gareth Williams
2019-09-18T08:05:29Z

From: Phil Edworthy <phil.edworthy@renesas.com>

Enable runtime PM so that the clock used to access the registers in the
peripheral is turned on using a clock domain.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Gareth Williams <gareth.williams.jx@renesas.com>
---
v2:
- set spi_controller.auto_runtime_pm instead of using
pm_runtime_get_sync.
- Added pm_runtime_disable calls to dw_spi_remove_host and the error
condition of dw_spi_add_host.
---
drivers/spi/spi-dw.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 9a49e07..54ed6eb 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/delay.h>
+#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>

@@ -493,10 +494,13 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
master->dev.of_node = dev->of_node;
master->dev.fwnode = dev->fwnode;
master->flags = SPI_MASTER_GPIO_SS;
+ master->auto_runtime_pm = true;

if (dws->set_cs)
master->set_cs = dws->set_cs;

+ pm_runtime_enable(dev);
+
/* Basic HW init */
spi_hw_init(dev, dws);

@@ -525,6 +529,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
spi_enable_chip(dws, 0);
free_irq(dws->irq, master);
err_free_master:
+ pm_runtime_disable(dev);
spi_controller_put(master);
return ret;
}
@@ -539,6 +544,9 @@ void dw_spi_remove_host(struct dw_spi *dws)

spi_shutdown_chip(dws);

+ if (dws->master)
+ pm_runtime_disable(&dws->master->dev);
+
free_irq(dws->irq, dws->master);
}
EXPORT_SYMBOL_GPL(dw_spi_remove_host);
--
2.7.4