System on chip designs may specify a specific MMC power sequence. To
successfully detect an (e)MMC/SD/SDIO card, that power sequence must
be followed while initializing the card.
To be able to handle these SOC specific power sequences, let's add a
MMC power sequence interface. It provides the following functions to
help the mmc core to deal with these power sequences.
mmc_pwrseq_alloc() - Invoked from mmc_of_parse(), to initialize data.
mmc_pwrseq_pre_power_on()- Invoked in the beginning of mmc_power_up().
mmc_pwrseq_post_power_on()- Invoked at the end in mmc_power_up().
mmc_pwrseq_power_off()- Invoked from mmc_power_off().
mmc_pwrseq_free() - Invoked from mmc_free_host(), to free data.
Each MMC power sequence provider will be responsible to implement a set
of callbacks. These callbacks mirrors the functions above.
This patch adds the skeleton, following patches will extend the core of
the MMC power sequence and add support for a specific simple MMC power
sequence.
Do note, since the mmc_pwrseq_alloc() is invoked from mmc_of_parse(),
host drivers needs to make use of this API to enable the support for
MMC power sequences. Moreover the MMC power sequence support depends on
CONFIG_OF.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
Changes in v2:
Fixed comments from Russell King:
- Renamed pwrseq callbacks and corresponding interface functions.
- Move the call to the previous namned ->power_on() callback, to the
end of mmc_power_up() to get consistent behavior.
- Updated commit message according to the above changes.
---
drivers/mmc/core/Makefile | 2 +-
drivers/mmc/core/core.c | 7 +++++++
drivers/mmc/core/host.c | 4 +++-
drivers/mmc/core/pwrseq.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/mmc/core/pwrseq.h | 40 +++++++++++++++++++++++++++++++++++++
include/linux/mmc/host.h | 2 ++
6 files changed, 103 insertions(+), 2 deletions(-)
create mode 100644 drivers/mmc/core/pwrseq.c
create mode 100644 drivers/mmc/core/pwrseq.h
diff --git a/drivers/mmc/core/Makefile b/drivers/mmc/core/Makefile
index 38ed210..ccdd35f 100644
--- a/drivers/mmc/core/Makefile
+++ b/drivers/mmc/core/Makefile
@@ -8,5 +8,5 @@ mmc_core-y := core.o bus.o host.o \
sdio.o sdio_ops.o sdio_bus.o \
sdio_cis.o sdio_io.o sdio_irq.o \
quirks.o slot-gpio.o
-
+mmc_core-$(CONFIG_OF) += pwrseq.o
mmc_core-$(CONFIG_DEBUG_FS) += debugfs.o
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index d5c176e..1be7055 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -40,6 +40,7 @@
#include "bus.h"
#include "host.h"
#include "sdio_bus.h"
+#include "pwrseq.h"
#include "mmc_ops.h"
#include "sd_ops.h"
@@ -1615,6 +1616,8 @@ void mmc_power_up(struct mmc_host *host, u32 ocr)
mmc_host_clk_hold(host);
+ mmc_pwrseq_pre_power_on(host);
+
host->ios.vdd = fls(ocr) - 1;
host->ios.power_mode = MMC_POWER_UP;
/* Set initial state and call mmc_set_ios */
@@ -1645,6 +1648,8 @@ void mmc_power_up(struct mmc_host *host, u32 ocr)
*/
mmc_delay(10);
+ mmc_pwrseq_post_power_on(host);
+
mmc_host_clk_release(host);
}
@@ -1655,6 +1660,8 @@ void mmc_power_off(struct mmc_host *host)
mmc_host_clk_hold(host);
+ mmc_pwrseq_power_off(host);
+
host->ios.clock = 0;
host->ios.vdd = 0;
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 0763644..8be0df7 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -30,6 +30,7 @@
#include "core.h"
#include "host.h"
#include "slot-gpio.h"
+#include "pwrseq.h"
#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
@@ -448,7 +449,7 @@ int mmc_of_parse(struct mmc_host *host)
host->dsr_req = 0;
}
- return 0;
+ return mmc_pwrseq_alloc(host);
}
EXPORT_SYMBOL(mmc_of_parse);
@@ -588,6 +589,7 @@ EXPORT_SYMBOL(mmc_remove_host);
*/
void mmc_free_host(struct mmc_host *host)
{
+ mmc_pwrseq_free(host);
put_device(&host->class_dev);
}
diff --git a/drivers/mmc/core/pwrseq.c b/drivers/mmc/core/pwrseq.c
new file mode 100644
index 0000000..bd08772
--- /dev/null
+++ b/drivers/mmc/core/pwrseq.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd
+ *
+ * Author: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ * MMC power sequence management
+ */
+#include <linux/mmc/host.h>
+
+#include "pwrseq.h"
+
+
+int mmc_pwrseq_alloc(struct mmc_host *host)
+{
+ return 0;
+}
+
+void mmc_pwrseq_pre_power_on(struct mmc_host *host)
+{
+ struct mmc_pwrseq *pwrseq = host->pwrseq;
+
+ if (pwrseq && pwrseq->ops && pwrseq->ops->pre_power_on)
+ pwrseq->ops->pre_power_on(host);
+}
+
+void mmc_pwrseq_post_power_on(struct mmc_host *host)
+{
+ struct mmc_pwrseq *pwrseq = host->pwrseq;
+
+ if (pwrseq && pwrseq->ops && pwrseq->ops->post_power_on)
+ pwrseq->ops->post_power_on(host);
+}
+
+void mmc_pwrseq_power_off(struct mmc_host *host)
+{
+ struct mmc_pwrseq *pwrseq = host->pwrseq;
+
+ if (pwrseq && pwrseq->ops && pwrseq->ops->power_off)
+ pwrseq->ops->power_off(host);
+}
+
+void mmc_pwrseq_free(struct mmc_host *host)
+{
+ struct mmc_pwrseq *pwrseq = host->pwrseq;
+
+ if (pwrseq && pwrseq->ops && pwrseq->ops->free)
+ pwrseq->ops->free(host);
+}
diff --git a/drivers/mmc/core/pwrseq.h b/drivers/mmc/core/pwrseq.h
new file mode 100644
index 0000000..12aaf2b
--- /dev/null
+++ b/drivers/mmc/core/pwrseq.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd
+ *
+ * Author: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+#ifndef _MMC_CORE_PWRSEQ_H
+#define _MMC_CORE_PWRSEQ_H
+
+struct mmc_pwrseq_ops {
+ void (*pre_power_on)(struct mmc_host *host);
+ void (*post_power_on)(struct mmc_host *host);
+ void (*power_off)(struct mmc_host *host);
+ void (*free)(struct mmc_host *host);
+};
+
+struct mmc_pwrseq {
+ struct mmc_pwrseq_ops *ops;
+};
+
+#ifdef CONFIG_OF
+
+int mmc_pwrseq_alloc(struct mmc_host *host);
+void mmc_pwrseq_pre_power_on(struct mmc_host *host);
+void mmc_pwrseq_post_power_on(struct mmc_host *host);
+void mmc_pwrseq_power_off(struct mmc_host *host);
+void mmc_pwrseq_free(struct mmc_host *host);
+
+#else
+
+static inline int mmc_pwrseq_alloc(struct mmc_host *host) { return 0; }
+static inline void mmc_pwrseq_pre_power_on(struct mmc_host *host) {}
+static inline void mmc_pwrseq_post_power_on(struct mmc_host *host) {}
+static inline void mmc_pwrseq_power_off(struct mmc_host *host) {}
+static inline void mmc_pwrseq_free(struct mmc_host *host) {}
+
+#endif
+
+#endif
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index b6bf718..0c8cbe5 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -195,6 +195,7 @@ struct mmc_context_info {
};
struct regulator;
+struct mmc_pwrseq;
struct mmc_supply {
struct regulator *vmmc; /* Card power supply */
@@ -206,6 +207,7 @@ struct mmc_host {
struct device class_dev;
int index;
const struct mmc_host_ops *ops;
+ struct mmc_pwrseq *pwrseq;
unsigned int f_min;
unsigned int f_max;
unsigned int f_init;
--
1.9.1
--
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