From 8f9165c981fed187bb483de84caf9adf835aefda Mon Sep 17 00:00:00 2001 From: Jan Remmet Date: Fri, 23 Sep 2016 10:52:00 +0200 Subject: 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 Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/regulator/tps65910-regulator.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/regulator') 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; -- cgit v1.2.3