From 9ec4f4b0e9fd3ad4b9a38bddb75b516ea09f4628 Mon Sep 17 00:00:00 2001 From: Ravi Kumar Bokka Date: Tue, 30 Mar 2021 12:12:34 +0100 Subject: drivers: nvmem: Fix voltage settings for QTI qfprom-efuse QFPROM controller hardware requires 1.8V min for fuse blowing. So, this change sets the voltage to 1.8V, required to blow the fuse for qfprom-efuse controller. To disable fuse blowing, we set the voltage to 0V since this may be a shared rail and may be able to run at a lower rate when we're not blowing fuses. Fixes: 93b4e49f8c86 ("nvmem: qfprom: Add fuse blowing support") Reported-by: Douglas Anderson Suggested-by: Douglas Anderson Reviewed-by: Douglas Anderson Signed-off-by: Ravi Kumar Bokka Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20210330111241.19401-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/qfprom.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'drivers/nvmem') diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c index 6cace24dfbf7..100d69d8f2e1 100644 --- a/drivers/nvmem/qfprom.c +++ b/drivers/nvmem/qfprom.c @@ -127,6 +127,16 @@ static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv, { int ret; + /* + * This may be a shared rail and may be able to run at a lower rate + * when we're not blowing fuses. At the moment, the regulator framework + * applies voltage constraints even on disabled rails, so remove our + * constraints and allow the rail to be adjusted by other users. + */ + ret = regulator_set_voltage(priv->vcc, 0, INT_MAX); + if (ret) + dev_warn(priv->dev, "Failed to set 0 voltage (ignoring)\n"); + ret = regulator_disable(priv->vcc); if (ret) dev_warn(priv->dev, "Failed to disable regulator (ignoring)\n"); @@ -172,6 +182,17 @@ static int qfprom_enable_fuse_blowing(const struct qfprom_priv *priv, goto err_clk_prepared; } + /* + * Hardware requires 1.8V min for fuse blowing; this may be + * a rail shared do don't specify a max--regulator constraints + * will handle. + */ + ret = regulator_set_voltage(priv->vcc, 1800000, INT_MAX); + if (ret) { + dev_err(priv->dev, "Failed to set 1.8 voltage\n"); + goto err_clk_rate_set; + } + ret = regulator_enable(priv->vcc); if (ret) { dev_err(priv->dev, "Failed to enable regulator\n"); -- cgit