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| author | Sascha Hauer | 2014-08-19 10:45:51 +0200 |
|---|---|---|
| committer | Ulf Hansson | 2014-09-09 13:59:07 +0200 |
| commit | 3d705d14fe4c72be83bae1610680e209ee226b9d (patch) | |
| tree | f62e06a2feffe512962cf2ec00baccf52460cdbf /drivers/mmc/core/mmc_ops.h | |
| parent | mmc: sdhci-pxav3: set_uhs_signaling is initialized twice differently (diff) | |
| download | kernel-qcow2-linux-3d705d14fe4c72be83bae1610680e209ee226b9d.tar.gz kernel-qcow2-linux-3d705d14fe4c72be83bae1610680e209ee226b9d.tar.xz kernel-qcow2-linux-3d705d14fe4c72be83bae1610680e209ee226b9d.zip | |
mmc: implement Driver Stage Register handling
Some eMMC and SD cards implement a DSR register that allows to tune
raise/fall times and drive strength of the CMD and DATA outputs.
The values to use depend on the card in use and the host.
It might be needed to reduce the drive strength to prevent voltage peaks
above the host's specification.
Implement a 'dsr' devicetree property that allows to specify the value
to set the DSR to. For non-dt setups the new members of mmc_host can be
set by board code.
This patch was initially authored by Sascha Hauer. It contains
improvements authored by Markus Niebel and Uwe Kleine-König.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core/mmc_ops.h')
| -rw-r--r-- | drivers/mmc/core/mmc_ops.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h index 80ae9f4e0293..390dac665b2a 100644 --- a/drivers/mmc/core/mmc_ops.h +++ b/drivers/mmc/core/mmc_ops.h @@ -14,6 +14,7 @@ int mmc_select_card(struct mmc_card *card); int mmc_deselect_cards(struct mmc_host *host); +int mmc_set_dsr(struct mmc_host *host); int mmc_go_idle(struct mmc_host *host); int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr); int mmc_all_send_cid(struct mmc_host *host, u32 *cid); |