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authorRavi Kumar Bokka <rbokka@codeaurora.org>2021-03-30 13:12:34 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-04-02 16:26:33 +0200
commit9ec4f4b0e9fd3ad4b9a38bddb75b516ea09f4628 (patch)
tree69d9157a6265bb0c48333054626a30b9f8baabeb /drivers/nvmem/qfprom.c
parentnvmem: convert comma to semicolon (diff)
downloadlinux-9ec4f4b0e9fd3ad4b9a38bddb75b516ea09f4628.tar.xz
linux-9ec4f4b0e9fd3ad4b9a38bddb75b516ea09f4628.zip
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 <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.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvmem/qfprom.c')
-rw-r--r--drivers/nvmem/qfprom.c21
1 files changed, 21 insertions, 0 deletions
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");