[PATCH 1/1] mfd: db8500-prcmu: update hostport_access enable

From: Arun Murthy
Date: Mon May 21 2012 - 04:58:37 EST


Force the Modem wakeup by asserting the CaWakeReq signal before the
hostaccess_req/ack ping-pong sequence. The Awake_req signal is de-asserted
asserted at the same time than the hostaccess_req. Return error on failure
case so that the client using this can take appropiate steps.

Signed-off-by: Arun Murthy <arun.murthy@xxxxxxxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
drivers/mfd/db8500-prcmu.c | 45 ++++++++++++++++----------------------
drivers/mfd/dbx500-prcmu-regs.h | 1 +
include/linux/mfd/db8500-prcmu.h | 7 ++++-
include/linux/mfd/dbx500-prcmu.h | 7 ++++-
4 files changed, 30 insertions(+), 30 deletions(-)

diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index 671c8bc..084d27c 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -2269,10 +2269,10 @@ int prcmu_abb_write(u8 slave, u8 reg, u8 *value, u8 size)
/**
* prcmu_ac_wake_req - should be called whenever ARM wants to wakeup Modem
*/
-void prcmu_ac_wake_req(void)
+int prcmu_ac_wake_req(void)
{
u32 val;
- u32 status;
+ int ret = 0;

mutex_lock(&mb0_transfer.ac_wake_lock);

@@ -2282,39 +2282,32 @@ void prcmu_ac_wake_req(void)

atomic_set(&ac_wake_req_state, 1);

-retry:
- writel((val | PRCM_HOSTACCESS_REQ_HOSTACCESS_REQ), PRCM_HOSTACCESS_REQ);
+ /*
+ * Force Modem Wake-up before hostaccess_req ping-pong.
+ * It prevents Modem to enter in Sleep while acking the hostaccess
+ * request. The 31us delay has been calculated by HWI.
+ */
+ val |= PRCM_HOSTACCESS_REQ_WAKE_REQ;
+ writel(val, PRCM_HOSTACCESS_REQ);
+
+ udelay(31);
+
+ val |= PRCM_HOSTACCESS_REQ_HOSTACCESS_REQ;
+ writel(val, PRCM_HOSTACCESS_REQ);

if (!wait_for_completion_timeout(&mb0_transfer.ac_wake_work,
msecs_to_jiffies(5000))) {
+#if defined(CONFIG_DBX500_PRCMU_DEBUG)
+ db8500_prcmu_debug_dump(__func__, true, true);
+#endif
pr_crit("prcmu: %s timed out (5 s) waiting for a reply.\n",
__func__);
- goto unlock_and_return;
- }
-
- /*
- * The modem can generate an AC_WAKE_ACK, and then still go to sleep.
- * As a workaround, we wait, and then check that the modem is indeed
- * awake (in terms of the value of the PRCM_MOD_AWAKE_STATUS
- * register, which may not be the whole truth).
- */
- udelay(400);
- status = (readl(PRCM_MOD_AWAKE_STATUS) & BITS(0, 2));
- if (status != (PRCM_MOD_AWAKE_STATUS_PRCM_MOD_AAPD_AWAKE |
- PRCM_MOD_AWAKE_STATUS_PRCM_MOD_COREPD_AWAKE)) {
- pr_err("prcmu: %s received ack, but modem not awake (0x%X).\n",
- __func__, status);
- udelay(1200);
- writel(val, PRCM_HOSTACCESS_REQ);
- if (wait_for_completion_timeout(&mb0_transfer.ac_wake_work,
- msecs_to_jiffies(5000)))
- goto retry;
- pr_crit("prcmu: %s timed out (5 s) waiting for AC_SLEEP_ACK.\n",
- __func__);
+ ret = -EFAULT;
}

unlock_and_return:
mutex_unlock(&mb0_transfer.ac_wake_lock);
+ return ret;
}

/**
diff --git a/drivers/mfd/dbx500-prcmu-regs.h b/drivers/mfd/dbx500-prcmu-regs.h
index 3a0bf91..23108a6 100644
--- a/drivers/mfd/dbx500-prcmu-regs.h
+++ b/drivers/mfd/dbx500-prcmu-regs.h
@@ -106,6 +106,7 @@

#define PRCM_HOSTACCESS_REQ (_PRCMU_BASE + 0x334)
#define PRCM_HOSTACCESS_REQ_HOSTACCESS_REQ 0x1
+#define PRCM_HOSTACCESS_REQ_WAKE_REQ BIT(16)
#define ARM_WAKEUP_MODEM 0x1

#define PRCM_ARM_IT1_CLR (_PRCMU_BASE + 0x48C)
diff --git a/include/linux/mfd/db8500-prcmu.h b/include/linux/mfd/db8500-prcmu.h
index b3a43b1..b82f6ee 100644
--- a/include/linux/mfd/db8500-prcmu.h
+++ b/include/linux/mfd/db8500-prcmu.h
@@ -530,7 +530,7 @@ int db8500_prcmu_stop_temp_sense(void);
int prcmu_abb_read(u8 slave, u8 reg, u8 *value, u8 size);
int prcmu_abb_write(u8 slave, u8 reg, u8 *value, u8 size);

-void prcmu_ac_wake_req(void);
+int prcmu_ac_wake_req(void);
void prcmu_ac_sleep_req(void);
void db8500_prcmu_modem_reset(void);

@@ -680,7 +680,10 @@ static inline int prcmu_abb_write(u8 slave, u8 reg, u8 *value, u8 size)
return -ENOSYS;
}

-static inline void prcmu_ac_wake_req(void) {}
+static inline int prcmu_ac_wake_req(void)
+{
+ return 0;
+}

static inline void prcmu_ac_sleep_req(void) {}

diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
index 5a13f93..5b90e94 100644
--- a/include/linux/mfd/dbx500-prcmu.h
+++ b/include/linux/mfd/dbx500-prcmu.h
@@ -345,7 +345,7 @@ static inline u16 prcmu_get_reset_code(void)
return db8500_prcmu_get_reset_code();
}

-void prcmu_ac_wake_req(void);
+int prcmu_ac_wake_req(void);
void prcmu_ac_sleep_req(void);
static inline void prcmu_modem_reset(void)
{
@@ -533,7 +533,10 @@ static inline u16 prcmu_get_reset_code(void)
return 0;
}

-static inline void prcmu_ac_wake_req(void) {}
+static inline int prcmu_ac_wake_req(void)
+{
+ return 0;
+}

static inline void prcmu_ac_sleep_req(void) {}

--
1.7.4.3

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