From: Ravi Kumar Bokka rbokka@codeaurora.org
[ Upstream commit 9ec4f4b0e9fd3ad4b9a38bddb75b516ea09f4628 ]
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 dianders@chromium.org Suggested-by: Douglas Anderson dianders@chromium.org Reviewed-by: Douglas Anderson dianders@chromium.org Signed-off-by: Ravi Kumar Bokka rbokka@codeaurora.org Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org Link: https://lore.kernel.org/r/20210330111241.19401-4-srinivas.kandagatla@linaro.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvmem/qfprom.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
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");