Thread (7 messages) 7 messages, 5 authors, 2025-08-07

Re: [PATCH] i2c: mt65xx: allow optional pmic clock

From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Date: 2023-09-14 09:38:00
Also in: linux-i2c, linux-mediatek, lkml

Il 14/09/23 11:07, Daniel Golle ha scritto:
On Wed, Sep 13, 2023 at 04:00:53PM +0200, AngeloGioacchino Del Regno wrote:
quoted
Il 27/08/23 04:13, Daniel Golle ha scritto:
quoted
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(-)
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 1a9b5a068ef1b..a8b5719c33729 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -1442,15 +1442,19 @@ static int mtk_i2c_probe(struct platform_device *pdev)
   	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) {
...but you're not changing speed_clk if !i2c->have_pmic, I'm not sure that
this will work correctly. Perhaps you wanted to also set speed_clk if the
clock is present?
No, if I wanted that I could have used the existing 'mediatek,have-pmic'
property -- however, all needed e.g. on MT7981 is to make sure the
clock is enabled, but still use I2C_MT65XX_CLK_MAIN as speed_clk.
Sorry, I've misunderstood the intention and yes, I understand now.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>



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