[PATCH v5 13/36] i2c: tegra: Clean up probe function

[Dmitry Osipenko]

The driver's probe function code is a bit difficult to read. This patch
reorders code of the probe function, forming groups of code that are easy
to work with. The reset_control_get() now may return -EPROBE_DEFER on
newer Tegra SoCs because they use BPMP driver that provides reset controls
and BPMP doesn't come up early during boot, previously rst was protected
by other checks error checks in the code, hence dev_err_probe() is used
now for the rst. The probe tear-down order now matches the driver-removal
order.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
 drivers/i2c/busses/i2c-tegra.c | 145 +++++++++++++++++----------------
 1 file changed, 73 insertions(+), 72 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index ae4b80b522ab..b4df0351252e 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -440,6 +440,9 @@ static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
 
 	i2c_dev->tx_dma_chan = chan;
 
+	i2c_dev->dma_buf_size = i2c_dev->hw->quirks->max_write_len +
+				I2C_PACKET_HEADER_SIZE;
+
 	dma_buf = dma_alloc_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
 				     &dma_phys, GFP_KERNEL | __GFP_NOWARN);
 	if (!dma_buf) {
@@ -1680,57 +1683,60 @@ static void tegra_i2c_release_clocks(struct tegra_i2c_dev *i2c_dev)
 
 static int tegra_i2c_probe(struct platform_device *pdev)
 {
-	struct device *dev = &pdev->dev;
 	struct tegra_i2c_dev *i2c_dev;
 	struct resource *res;
-	void __iomem *base;
-	phys_addr_t base_phys;
-	int irq;
-	int ret;
-
-	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
-	if (IS_ERR(base))
-		return PTR_ERR(base);
-
-	base_phys = res->start;
-
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
-		return irq;
+	int err;
 
 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
 	if (!i2c_dev)
 		return -ENOMEM;
 
-	i2c_dev->base = base;
-	i2c_dev->base_phys = base_phys;
-	i2c_dev->adapter.algo = &tegra_i2c_algo;
-	i2c_dev->adapter.retries = 1;
-	i2c_dev->adapter.timeout = 6 * HZ;
-	i2c_dev->irq = irq;
+	platform_set_drvdata(pdev, i2c_dev);
+
+	init_completion(&i2c_dev->msg_complete);
+	init_completion(&i2c_dev->dma_complete);
+
+	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
 	i2c_dev->cont_id = pdev->id;
 	i2c_dev->dev = &pdev->dev;
 
-	i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c");
+	i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(i2c_dev->base))
+		return PTR_ERR(i2c_dev->base);
+
+	i2c_dev->base_phys = res->start;
+
+	err = platform_get_irq(pdev, 0);
+	if (err < 0)
+		return err;
+
+	i2c_dev->irq = err;
+
+	/* interrupt will be enabled during of transfer time */
+	irq_set_status_flags(i2c_dev->irq, IRQ_NOAUTOEN);
+
+	err = devm_request_irq(i2c_dev->dev, i2c_dev->irq, tegra_i2c_isr,
+			       IRQF_NO_SUSPEND, dev_name(i2c_dev->dev),
+			       i2c_dev);
+	if (err)
+		return err;
+
+	i2c_dev->rst = devm_reset_control_get_exclusive(i2c_dev->dev, "i2c");
 	if (IS_ERR(i2c_dev->rst)) {
-		dev_err(&pdev->dev, "missing controller reset\n");
+		dev_err_probe(i2c_dev->dev, PTR_ERR(i2c_dev->rst),
+			      "failed to get reset control\n");
 		return PTR_ERR(i2c_dev->rst);
 	}
 
 	tegra_i2c_parse_dt(i2c_dev);
 
-	ret = tegra_i2c_init_clocks(i2c_dev);
-	if (ret)
-		return ret;
-
-	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
-	i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
-	i2c_dev->dma_buf_size = i2c_dev->adapter.quirks->max_write_len +
-				I2C_PACKET_HEADER_SIZE;
-	init_completion(&i2c_dev->msg_complete);
-	init_completion(&i2c_dev->dma_complete);
+	err = tegra_i2c_init_clocks(i2c_dev);
+	if (err)
+		return err;
 
-	platform_set_drvdata(pdev, i2c_dev);
+	err = tegra_i2c_init_dma(i2c_dev);
+	if (err)
+		goto release_clocks;
 
 	/*
 	 * VI I2C is in VE power domain which is not always on and not
@@ -1740,62 +1746,57 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	 * not be used for atomic transfers.
 	 */
 	if (!i2c_dev->is_vi)
-		pm_runtime_irq_safe(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
-	ret = pm_runtime_get_sync(i2c_dev->dev);
-	if (ret < 0) {
-		dev_err(dev, "runtime resume failed\n");
+		pm_runtime_irq_safe(i2c_dev->dev);
+
+	pm_runtime_enable(i2c_dev->dev);
+
+	err = pm_runtime_get_sync(i2c_dev->dev);
+	if (err < 0) {
+		dev_err(i2c_dev->dev, "runtime resume failed: %d\n", err);
 		goto disable_rpm;
 	}
 
-	if (i2c_dev->hw->supports_bus_clear)
-		i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;
-
-	ret = tegra_i2c_init_dma(i2c_dev);
-	if (ret < 0)
+	/* initialize hardware state */
+	err = tegra_i2c_init(i2c_dev);
+	if (err)
 		goto put_rpm;
 
-	ret = tegra_i2c_init(i2c_dev);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
-		goto release_dma;
-	}
+	i2c_dev->adapter.dev.of_node = i2c_dev->dev->of_node;
+	i2c_dev->adapter.dev.parent = i2c_dev->dev;
+	i2c_dev->adapter.retries = 1;
+	i2c_dev->adapter.timeout = 6 * HZ;
+	i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
+	i2c_dev->adapter.owner = THIS_MODULE;
+	i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
+	i2c_dev->adapter.algo = &tegra_i2c_algo;
+	i2c_dev->adapter.nr = i2c_dev->cont_id;
 
-	irq_set_status_flags(i2c_dev->irq, IRQ_NOAUTOEN);
+	if (i2c_dev->hw->supports_bus_clear)
+		i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;
 
-	ret = devm_request_irq(&pdev->dev, i2c_dev->irq, tegra_i2c_isr,
-			       IRQF_NO_SUSPEND, dev_name(&pdev->dev), i2c_dev);
-	if (ret)
-		goto release_dma;
+	strlcpy(i2c_dev->adapter.name, dev_name(i2c_dev->dev),
+		sizeof(i2c_dev->adapter.name));
 
 	i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
-	i2c_dev->adapter.owner = THIS_MODULE;
-	i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
-	strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev),
-		sizeof(i2c_dev->adapter.name));
-	i2c_dev->adapter.dev.parent = &pdev->dev;
-	i2c_dev->adapter.nr = pdev->id;
-	i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
 
-	ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
-	if (ret)
-		goto release_dma;
+	err = i2c_add_numbered_adapter(&i2c_dev->adapter);
+	if (err)
+		goto put_rpm;
 
-	pm_runtime_put(&pdev->dev);
+	pm_runtime_put(i2c_dev->dev);
 
 	return 0;
 
-release_dma:
-	tegra_i2c_release_dma(i2c_dev);
-
 put_rpm:
-	pm_runtime_put_sync(&pdev->dev);
-
+	pm_runtime_put(i2c_dev->dev);
 disable_rpm:
-	pm_runtime_disable(&pdev->dev);
+	pm_runtime_disable(i2c_dev->dev);
+
+	tegra_i2c_release_dma(i2c_dev);
+release_clocks:
 	tegra_i2c_release_clocks(i2c_dev);
 
-	return ret;
+	return err;
 }
 
 static int tegra_i2c_remove(struct platform_device *pdev)
-- 
2.27.0