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authorJan Remmet <j.remmet@phytec.de>2016-09-23 11:52:00 +0300
committerMark Brown <broonie@kernel.org>2016-09-24 21:04:36 +0300
commit8f9165c981fed187bb483de84caf9adf835aefda (patch)
treeb1abe78be6f559cc7b2ed736fef64a79b107de99
parent29b4817d4018df78086157ea3a55c1d9424a7cfc (diff)
downloadlinux-8f9165c981fed187bb483de84caf9adf835aefda.tar.xz
regulator: tps65910: Work around silicon erratum SWCZ010
http://www.ti.com/lit/pdf/SWCZ010: DCDC o/p voltage can go higher than programmed value Impact: VDDI, VDD2, and VIO output programmed voltage level can go higher than expected or crash, when coming out of PFM to PWM mode or using DVFS. Description: When DCDC CLK SYNC bits are 11/01: * VIO 3-MHz oscillator is the source clock of the digital core and input clock of VDD1 and VDD2 * Turn-on of VDD1 and VDD2 HSD PFETis synchronized or at a constant phase shift * Current pulled though VCC1+VCC2 is Iload(VDD1) + Iload(VDD2) * The 3 HSD PFET will be turned-on at the same time, causing the highest possible switching noise on the application. This noise level depends on the layout, the VBAT level, and the load current. The noise level increases with improper layout. When DCDC CLK SYNC bits are 00: * VIO 3-MHz oscillator is the source clock of digital core * VDD1 and VDD2 are running on their own 3-MHz oscillator * Current pulled though VCC1+VCC2 average of Iload(VDD1) + Iload(VDD2) * The switching noise of the 3 SMPS will be randomly spread over time, causing lower overall switching noise. Workaround: Set DCDCCTRL_REG[1:0]= 00. Signed-off-by: Jan Remmet <j.remmet@phytec.de> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
-rw-r--r--drivers/regulator/tps65910-regulator.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/regulator/tps65910-regulator.c b/drivers/regulator/tps65910-regulator.c
index fb991ec76423..696116ebdf50 100644
--- a/drivers/regulator/tps65910-regulator.c
+++ b/drivers/regulator/tps65910-regulator.c
@@ -1111,6 +1111,12 @@ static int tps65910_probe(struct platform_device *pdev)
pmic->num_regulators = ARRAY_SIZE(tps65910_regs);
pmic->ext_sleep_control = tps65910_ext_sleep_control;
info = tps65910_regs;
+ /* Work around silicon erratum SWCZ010: output programmed
+ * voltage level can go higher than expected or crash
+ * Workaround: use no synchronization of DCDC clocks
+ */
+ tps65910_reg_clear_bits(pmic->mfd, TPS65910_DCDCCTRL,
+ DCDCCTRL_DCDCCKSYNC_MASK);
break;
case TPS65911:
pmic->get_ctrl_reg = &tps65911_get_ctrl_register;