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authorHeiner Kallweit <hkallweit1@gmail.com>2014-12-03 07:56:19 +0100
committerMark Brown <broonie@kernel.org>2014-12-03 13:05:47 +0000
commit75506d0e0084ee7f074be3c5da6d5de98ce347b6 (patch)
tree61bb3916c2f3f04206bc0639e287b50ee23e2a0e /drivers/spi
parentc592becbe704127ef0b89233ff7f285637491154 (diff)
spi: fsl-espi: add (un)prepare_transfer_hardware calls to save power if SPI is not in use
Use (un)prepare_transfer_hardware calls to set fsl-espi to low-power idle if not in use. Reference manual states: "The eSPI is in a idle state and consumes minimal power. The eSPI BRG is not functioning and the input clock is disabled" Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-fsl-espi.c46
1 files changed, 35 insertions, 11 deletions
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 90be6405e78..56cadf13519 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -588,6 +588,38 @@ static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
iounmap(mspi->reg_base);
}
+static int fsl_espi_suspend(struct spi_master *master)
+{
+ struct mpc8xxx_spi *mpc8xxx_spi;
+ struct fsl_espi_reg *reg_base;
+ u32 regval;
+
+ mpc8xxx_spi = spi_master_get_devdata(master);
+ reg_base = mpc8xxx_spi->reg_base;
+
+ regval = mpc8xxx_spi_read_reg(&reg_base->mode);
+ regval &= ~SPMODE_ENABLE;
+ mpc8xxx_spi_write_reg(&reg_base->mode, regval);
+
+ return 0;
+}
+
+static int fsl_espi_resume(struct spi_master *master)
+{
+ struct mpc8xxx_spi *mpc8xxx_spi;
+ struct fsl_espi_reg *reg_base;
+ u32 regval;
+
+ mpc8xxx_spi = spi_master_get_devdata(master);
+ reg_base = mpc8xxx_spi->reg_base;
+
+ regval = mpc8xxx_spi_read_reg(&reg_base->mode);
+ regval |= SPMODE_ENABLE;
+ mpc8xxx_spi_write_reg(&reg_base->mode, regval);
+
+ return 0;
+}
+
static struct spi_master * fsl_espi_probe(struct device *dev,
struct resource *mem, unsigned int irq)
{
@@ -614,6 +646,8 @@ static struct spi_master * fsl_espi_probe(struct device *dev,
master->setup = fsl_espi_setup;
master->cleanup = fsl_espi_cleanup;
master->transfer_one_message = fsl_espi_do_one_msg;
+ master->prepare_transfer_hardware = fsl_espi_resume;
+ master->unprepare_transfer_hardware = fsl_espi_suspend;
mpc8xxx_spi = spi_master_get_devdata(master);
mpc8xxx_spi->spi_remove = fsl_espi_remove;
@@ -761,25 +795,15 @@ static int of_fsl_espi_remove(struct platform_device *dev)
static int of_fsl_espi_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
- struct mpc8xxx_spi *mpc8xxx_spi;
- struct fsl_espi_reg *reg_base;
- u32 regval;
int ret;
- mpc8xxx_spi = spi_master_get_devdata(master);
- reg_base = mpc8xxx_spi->reg_base;
-
ret = spi_master_suspend(master);
if (ret) {
dev_warn(dev, "cannot suspend master\n");
return ret;
}
- regval = mpc8xxx_spi_read_reg(&reg_base->mode);
- regval &= ~SPMODE_ENABLE;
- mpc8xxx_spi_write_reg(&reg_base->mode, regval);
-
- return 0;
+ return fsl_espi_suspend(master);
}
static int of_fsl_espi_resume(struct device *dev)