[PATCH] i2c/synquacer: Deal with optional PCLK correctly

[Ard Biesheuvel <ardb+git@google.com>]

From: Ard Biesheuvel <ardb@kernel.org>

ACPI boot does not provide clocks and regulators, but instead, provides
the PCLK rate directly, and enables the clock in firmware. So deal
gracefully with this.

Fixes: 55750148e559 ("i2c: synquacer: Fix an error handling path in synquacer_i2c_probe()")
Cc: <stable@vger.kernel.org>
Cc: Andi Shyti <andi.shyti@kernel.org>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
https://lore.kernel.org/all/CAMj1kXFH+zB_YuUS+vaEpguhuVGLYbQw55VNDCxnBfSPe6b-nw@mail.gmail.com/T/#u

 drivers/i2c/busses/i2c-synquacer.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-synquacer.c b/drivers/i2c/busses/i2c-synquacer.c
index 4eccbcd0fbfc..bbb9062669e4 100644
--- a/drivers/i2c/busses/i2c-synquacer.c
+++ b/drivers/i2c/busses/i2c-synquacer.c
@@ -550,12 +550,13 @@ static int synquacer_i2c_probe(struct platform_device *pdev)
 	device_property_read_u32(&pdev->dev, "socionext,pclk-rate",
 				 &i2c->pclkrate);
 
-	pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
+	pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk");
 	if (IS_ERR(pclk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(pclk),
 				     "failed to get and enable clock\n");
 
-	i2c->pclkrate = clk_get_rate(pclk);
+	if (pclk)
+		i2c->pclkrate = clk_get_rate(pclk);
 
 	if (i2c->pclkrate < SYNQUACER_I2C_MIN_CLK_RATE ||
 	    i2c->pclkrate > SYNQUACER_I2C_MAX_CLK_RATE)
-- 
2.46.0.662.g92d0881bb0-goog