From: Naveen Kaje <redacted>

Add support to get the device parameters from ACPI. Assume
that the clocks are managed by firmware.

Signed-off-by: Naveen Kaje <redacted>
Signed-off-by: Austin Christ <redacted>
---
drivers/i2c/busses/i2c-qup.c | 60 ++++++++++++++++++++++++++++++++------------
1 file changed, 44 insertions(+), 16 deletions(-)

Changes:
- v3:
- clean up unused variable
- v2:
- clean up redundant checks and variables

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index dddd4da..ea6ca5f 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c

@@ -29,6 +29,7 @@

#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/scatterlist.h>
+#include <linux/acpi.h>

/* QUP Registers */
#define QUP_CONFIG		0x000

@@ -132,6 +133,10 @@

/* Max timeout in ms for 32k bytes */
#define TOUT_MAX			300

+/* Default values. Use these if FW query fails */
+#define DEFAULT_CLK_FREQ 100000
+#define DEFAULT_SRC_CLK 20000000
+
struct qup_i2c_block {
	int	count;
	int	pos;

@@ -1354,14 +1359,13 @@ static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)

static int qup_i2c_probe(struct platform_device *pdev)
{
	static const int blk_sizes[] = {4, 16, 32};
-	struct device_node *node = pdev->dev.of_node;
	struct qup_i2c_dev *qup;
	unsigned long one_bit_t;
	struct resource *res;
	u32 io_mode, hw_ver, size;
	int ret, fs_div, hs_div;
-	int src_clk_freq;
-	u32 clk_freq = 100000;
+	u32 src_clk_freq = 0;
+	u32 clk_freq = 0;
	int blocks;

	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);

@@ -1372,7 +1376,12 @@ static int qup_i2c_probe(struct platform_device *pdev)

	init_completion(&qup->xfer);
	platform_set_drvdata(pdev, qup);

-	of_property_read_u32(node, "clock-frequency", &clk_freq);
+	ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
+	if (ret) {
+		dev_warn(qup->dev, "using default clock-frequency %d",
+			DEFAULT_CLK_FREQ);
+		clk_freq = DEFAULT_CLK_FREQ;
+	}

	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) {
		qup->adap.algo = &qup_i2c_algo;

@@ -1454,20 +1463,31 @@ nodma:

		return qup->irq;
	}

-	qup->clk = devm_clk_get(qup->dev, "core");
-	if (IS_ERR(qup->clk)) {
-		dev_err(qup->dev, "Could not get core clock\n");
-		return PTR_ERR(qup->clk);
-	}
+	if (ACPI_HANDLE(qup->dev)) {
+		ret = device_property_read_u32(qup->dev,
+				"src-clock-hz", &src_clk_freq);
+		if (ret) {
+			dev_warn(qup->dev, "using default src-clock-hz %d",
+				DEFAULT_SRC_CLK);
+			src_clk_freq = DEFAULT_SRC_CLK;
+		}
+		ACPI_COMPANION_SET(&qup->adap.dev, ACPI_COMPANION(qup->dev));
+	} else {
+		qup->clk = devm_clk_get(qup->dev, "core");
+		if (IS_ERR(qup->clk)) {
+			dev_err(qup->dev, "Could not get core clock\n");
+			return PTR_ERR(qup->clk);
+		}

-	qup->pclk = devm_clk_get(qup->dev, "iface");
-	if (IS_ERR(qup->pclk)) {
-		dev_err(qup->dev, "Could not get iface clock\n");
-		return PTR_ERR(qup->pclk);
+		qup->pclk = devm_clk_get(qup->dev, "iface");
+		if (IS_ERR(qup->pclk)) {
+			dev_err(qup->dev, "Could not get iface clock\n");
+			return PTR_ERR(qup->pclk);
+		}
+		qup_i2c_enable_clocks(qup);
+		src_clk_freq = clk_get_rate(qup->clk);
	}

-	qup_i2c_enable_clocks(qup);
-
	/*
	 * Bootloaders might leave a pending interrupt on certain QUP's,
	 * so we reset the core before registering for interrupts.

@@ -1514,7 +1534,6 @@ nodma:

	size = QUP_INPUT_FIFO_SIZE(io_mode);
	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);

-	src_clk_freq = clk_get_rate(qup->clk);
	fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
	hs_div = 3;
	qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);

@@ -1639,6 +1658,14 @@ static const struct of_device_id qup_i2c_dt_match[] = {

};
MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);

+#if IS_ENABLED(CONFIG_ACPI)
+static const struct acpi_device_id qup_i2c_acpi_match[] = {
+	{ "QCOM8010"},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_ids);
+#endif
+
static struct platform_driver qup_i2c_driver = {
	.probe  = qup_i2c_probe,
	.remove = qup_i2c_remove,

@@ -1646,6 +1673,7 @@ static struct platform_driver qup_i2c_driver = {

		.name = "i2c_qup",
		.pm = &qup_i2c_qup_pm_ops,
		.of_match_table = qup_i2c_dt_match,
+		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
	},
};