i2c: qcom-geni: Provide support for ACPI

Add a match table to allow automatic probing of ACPI device
QCOM0220.  Ignore clock attainment errors.  Set default clock
frequency value.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-qcom-geni.c

 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 
+#include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
@@ -483,6 +484,14 @@ static const struct i2c_algorithm geni_i2c_algo = {
 	.functionality	= geni_i2c_func,
 };
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id geni_i2c_acpi_match[] = {
+	{ "QCOM0220"},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match);
+#endif
+
 static int geni_i2c_probe(struct platform_device *pdev)
 {
 	struct geni_i2c_dev *gi2c;
@@ -502,7 +511,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(gi2c->se.base);
 
 	gi2c->se.clk = devm_clk_get(&pdev->dev, "se");
-	if (IS_ERR(gi2c->se.clk)) {
+	if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(&pdev->dev)) {
 		ret = PTR_ERR(gi2c->se.clk);
 		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
 		return ret;
@@ -516,6 +525,9 @@ static int geni_i2c_probe(struct platform_device *pdev)
 		gi2c->clk_freq_out = KHZ(100);
 	}
 
+	if (has_acpi_companion(&pdev->dev))
+		ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(&pdev->dev));
+
 	gi2c->irq = platform_get_irq(pdev, 0);
 	if (gi2c->irq < 0) {
 		dev_err(&pdev->dev, "IRQ error for i2c-geni\n");
@@ -662,6 +674,7 @@ static struct platform_driver geni_i2c_driver = {
 		.name = "geni_i2c",
 		.pm = &geni_i2c_pm_ops,
 		.of_match_table = geni_i2c_dt_match,
+		.acpi_match_table = ACPI_PTR(geni_i2c_acpi_match),
 	},
 };