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authorMark Brown <broonie@linaro.org>2013-07-27 15:29:58 +0400
committerMark Brown <broonie@linaro.org>2013-07-29 20:12:36 +0400
commit9f178c22fb0e88f4e84f7a66be8326f63b91e7e3 (patch)
treefef8c45930e90a6b7106fd14b15e9dd72c44f851 /drivers/spi/spi-tegra20-sflash.c
parentbb249aad82b93674281d8b76a0c9be2ba1d92d78 (diff)
downloadlinux-9f178c22fb0e88f4e84f7a66be8326f63b91e7e3.tar.xz
spi/tegra-sflash: Factor runtime PM out into transfer prepare/unprepare
Currently the tegra sflash driver acquires a runtime PM reference for the duration of each transfer. This may result in the IP being powered down between transfers which would be at best wasteful. Instead it is better to do this in the callbacks that are generated before and after starting a series of transfers, keeping the IP powered throughout. Signed-off-by: Mark Brown <broonie@linaro.org> Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Diffstat (limited to 'drivers/spi/spi-tegra20-sflash.c')
-rw-r--r--drivers/spi/spi-tegra20-sflash.c32
1 files changed, 25 insertions, 7 deletions
diff --git a/drivers/spi/spi-tegra20-sflash.c b/drivers/spi/spi-tegra20-sflash.c
index c1d5d95e70ea..f871c4ee6ad7 100644
--- a/drivers/spi/spi-tegra20-sflash.c
+++ b/drivers/spi/spi-tegra20-sflash.c
@@ -325,6 +325,20 @@ static int tegra_sflash_setup(struct spi_device *spi)
return 0;
}
+static int tegra_sflash_prepare_transfer(struct spi_master *spi)
+{
+ struct tegra_sflash_data *tsd = spi_master_get_devdata(spi);
+ int ret;
+
+ ret = pm_runtime_get_sync(tsd->dev);
+ if (ret < 0) {
+ dev_err(tsd->dev, "runtime PM get failed: %d\n", ret);
+ return ret;
+ }
+
+ return ret;
+}
+
static int tegra_sflash_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
@@ -335,12 +349,6 @@ static int tegra_sflash_transfer_one_message(struct spi_master *master,
struct spi_device *spi = msg->spi;
int ret;
- ret = pm_runtime_get_sync(tsd->dev);
- if (ret < 0) {
- dev_err(tsd->dev, "pm_runtime_get() failed, err = %d\n", ret);
- return ret;
- }
-
msg->status = 0;
msg->actual_length = 0;
single_xfer = list_is_singular(&msg->transfers);
@@ -380,10 +388,18 @@ exit:
tegra_sflash_writel(tsd, tsd->def_command_reg, SPI_COMMAND);
msg->status = ret;
spi_finalize_current_message(master);
- pm_runtime_put(tsd->dev);
return ret;
}
+static int tegra_sflash_unprepare_transfer(struct spi_master *spi)
+{
+ struct tegra_sflash_data *tsd = spi_master_get_devdata(spi);
+
+ pm_runtime_put(tsd->dev);
+
+ return 0;
+}
+
static irqreturn_t handle_cpu_based_xfer(struct tegra_sflash_data *tsd)
{
struct spi_transfer *t = tsd->curr_xfer;
@@ -476,7 +492,9 @@ static int tegra_sflash_probe(struct platform_device *pdev)
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA;
master->setup = tegra_sflash_setup;
+ master->prepare_transfer_hardware = tegra_sflash_prepare_transfer;
master->transfer_one_message = tegra_sflash_transfer_one_message;
+ master->unprepare_transfer_hardware = tegra_sflash_unprepare_transfer;
master->num_chipselect = MAX_CHIP_SELECT;
master->bus_num = -1;