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From: Axel Lin <axel.lin@ingics.com>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>,
	linux-kernel@vger.kernel.org,
	Laxman Dewangan <ldewangan@nvidia.com>
Subject: [PATCH] regulator: tps62360: Fix off-by-one shift for ramp_ctrl
Date: Tue, 23 Apr 2013 12:35:53 +0800	[thread overview]
Message-ID: <1366691753.25625.6.camel@phoenix> (raw)

According to the datasheet[1]

Register 0x06h Description: RmpCtrl (REGISTER ADDRESS: 0x06h Read/Write)
BIT[5..7]:
        RMP[2:0] Output voltage ramp timing
        D7-D5   Slope
        000     32mV/us
        001     16mV/us
        010     8mV/us
        ...
        110     0.5mV/us
        111     0.25mV/us

Thus to get correct ramp_ctrl value, we need to right-shift 5 bits.

[1] http://www.ti.com/lit/ds/symlink/tps62360.pdf

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
 drivers/regulator/tps62360-regulator.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/regulator/tps62360-regulator.c b/drivers/regulator/tps62360-regulator.c
index acbd63f..612919c 100644
--- a/drivers/regulator/tps62360-regulator.c
+++ b/drivers/regulator/tps62360-regulator.c
@@ -278,7 +278,7 @@ static int tps62360_init_dcdc(struct tps62360_chip *tps,
 			__func__, REG_RAMPCTRL, ret);
 		return ret;
 	}
-	ramp_ctrl = (ramp_ctrl >> 4) & 0x7;
+	ramp_ctrl = (ramp_ctrl >> 5) & 0x7;
 
 	/* ramp mV/us = 32/(2^ramp_ctrl) */
 	tps->desc.ramp_delay = DIV_ROUND_UP(32000, BIT(ramp_ctrl));
-- 
1.7.10.4




             reply	other threads:[~2013-04-23  4:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-23  4:35 Axel Lin [this message]
2013-04-23  6:18 ` [PATCH] regulator: tps62360: Fix off-by-one shift for ramp_ctrl Laxman Dewangan
2013-04-23 10:26 ` Mark Brown

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