[RFC 2/2] mmc: core: Add support for power sequences
From: Ulf Hansson <hidden>
Date: 2014-06-19 13:05:44
Also in:
linux-devicetree, linux-mmc, linux-pm, lkml
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Ulf Hansson, Linus Torvalds
The MMC subsystem uses a discoverable bus which sometimes means the power sequences to enable power to the card, is far too complex to be handled through the regular ->set_ios() callback. To adress these scenarios, we try to fetch a pwrseq method while parsing the common MMC DT bindings. If a such method is found we select the corresponding state for it from mmc_power_up|off(). Signed-off-by: Ulf Hansson <redacted> --- drivers/mmc/core/core.c | 7 +++++++ drivers/mmc/core/host.c | 5 +++++ include/linux/mmc/host.h | 3 +++ 3 files changed, 15 insertions(+)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7dc0c85..46558b5 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c@@ -29,6 +29,7 @@ #include <linux/random.h> #include <linux/slab.h> #include <linux/of.h> +#include <linux/pwrseq.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h>
@@ -1533,6 +1534,9 @@ void mmc_power_up(struct mmc_host *host, u32 ocr) mmc_host_clk_hold(host); + if (!IS_ERR(host->pwrseq)) + pwrseq_select_state(host->pwrseq, PWRSEQ_POWER_ON); + host->ios.vdd = fls(ocr) - 1; if (mmc_host_is_spi(host)) host->ios.chip_select = MMC_CS_HIGH;
@@ -1591,6 +1595,9 @@ void mmc_power_off(struct mmc_host *host) host->ios.timing = MMC_TIMING_LEGACY; mmc_set_ios(host); + if (!IS_ERR(host->pwrseq)) + pwrseq_select_state(host->pwrseq, PWRSEQ_POWER_OFF); + /* * Some configurations, such as the 802.11 SDIO card in the OLPC * XO-1.5, require a short delay after poweroff before the card
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 95cceae..fdf8596 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c@@ -22,6 +22,7 @@ #include <linux/leds.h> #include <linux/slab.h> #include <linux/suspend.h> +#include <linux/pwrseq.h> #include <linux/mmc/host.h> #include <linux/mmc/card.h>
@@ -317,6 +318,10 @@ int mmc_of_parse(struct mmc_host *host) if (!host->parent || !host->parent->of_node) return 0; + host->pwrseq = devm_pwrseq_get_optional(host->parent); + if (IS_ERR(host->pwrseq)) + return PTR_ERR(host->pwrseq); + np = host->parent->of_node; /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7960424..306b78c 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h@@ -195,9 +195,12 @@ struct mmc_supply { struct regulator *vqmmc; /* Optional Vccq supply */ }; +struct pwrseq; + struct mmc_host { struct device *parent; struct device class_dev; + struct pwrseq *pwrseq; int index; const struct mmc_host_ops *ops; unsigned int f_min;
--
1.7.9.5