mediatek: i2c: mt65xx: allow optional pmic clock

Using the I2C host controller on the MT7981 SoC requires 4 clocks to
be enabled. One of them, the pmic clk, is only enabled in case
'mediatek,have-pmic' is also set which has other consequences which
are not desired in this case.

Allow defining a pmic clk even in case the 'mediatek,have-pmic' propterty
is not present and the bus is not used to connect to a pmic, but may
still require to enable the pmic clock.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
(cherry picked from commit 2544dc34f2a6e5721096ee62efa66d36d45b2dd1)

diff --git a/target/linux/mediatek/patches-5.15/855-i2c-mt65xx-allow-optional-pmic-clock.patch b/target/linux/mediatek/patches-5.15/855-i2c-mt65xx-allow-optional-pmic-clock.patch
new file mode 100644 (file)
index 0000000..69cc155
--- /dev/null
+++ b/target/linux/mediatek/patches-5.15/855-i2c-mt65xx-allow-optional-pmic-clock.patch
@@ -0,0 +1,45 @@
+From 3bf827929a44c17bfb1bf1000b143c02ce26a929 Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Sat, 26 Aug 2023 21:56:51 +0100
+Subject: [PATCH] i2c: mt65xx: allow optional pmic clock
+
+Using the I2C host controller on the MT7981 SoC requires 4 clocks to
+be enabled. One of them, the pmic clk, is only enabled in case
+'mediatek,have-pmic' is also set which has other consequences which
+are not desired in this case.
+
+Allow defining a pmic clk even in case the 'mediatek,have-pmic' propterty
+is not present and the bus is not used to connect to a pmic, but may
+still require to enable the pmic clock.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/i2c/busses/i2c-mt65xx.c | 12 ++++++++----
+ 1 file changed, 8 insertions(+), 4 deletions(-)
+
+--- a/drivers/i2c/busses/i2c-mt65xx.c
++++ b/drivers/i2c/busses/i2c-mt65xx.c
+@@ -1444,15 +1444,19 @@ static int mtk_i2c_probe(struct platform
+       if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk))
+               return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk);
+ 
++      i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = devm_clk_get_optional(&pdev->dev, "pmic");
++      if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk)) {
++              dev_err(&pdev->dev, "cannot get pmic clock\n");
++              return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk);
++      }
++
+       if (i2c->have_pmic) {
+-              i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = devm_clk_get(&pdev->dev, "pmic");
+-              if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk)) {
++              if (!i2c->clocks[I2C_MT65XX_CLK_PMIC].clk) {
+                       dev_err(&pdev->dev, "cannot get pmic clock\n");
+-                      return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk);
++                      return -ENODEV;
+               }
+               speed_clk = I2C_MT65XX_CLK_PMIC;
+       } else {
+-              i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = NULL;
+               speed_clk = I2C_MT65XX_CLK_MAIN;
+       }
+