spi: tegra20-slink: Improve runtime PM usage

The Tegra SPI driver supports runtime PM, which controls the clock
enable state, but the clk is also enabled separately from the RPM
at the driver probe time, and thus, stays always on. Fix it.

Runtime PM now is always available on Tegra, hence there is no need to
check the RPM presence in the driver anymore. Remove these checks.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

drivers/spi/spi-tegra20-slink.c

@@ -1061,27 +1061,6 @@ static int tegra_slink_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "Can not get clock %d\n", ret);
 		goto exit_free_master;
 	}
-	ret = clk_prepare(tspi->clk);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Clock prepare failed %d\n", ret);
-		goto exit_free_master;
-	}
-	ret = clk_enable(tspi->clk);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Clock enable failed %d\n", ret);
-		goto exit_clk_unprepare;
-	}
-
-	spi_irq = platform_get_irq(pdev, 0);
-	tspi->irq = spi_irq;
-	ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
-			tegra_slink_isr_thread, IRQF_ONESHOT,
-			dev_name(&pdev->dev), tspi);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
-					tspi->irq);
-		goto exit_clk_disable;
-	}
 
 	tspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi");
 	if (IS_ERR(tspi->rst)) {
@@ -1106,50 +1085,53 @@ static int tegra_slink_probe(struct platform_device *pdev)
 	init_completion(&tspi->xfer_completion);
 
 	pm_runtime_enable(&pdev->dev);
-	if (!pm_runtime_enabled(&pdev->dev)) {
-		ret = tegra_slink_runtime_resume(&pdev->dev);
-		if (ret)
-			goto exit_pm_disable;
-	}
-
-	ret = pm_runtime_get_sync(&pdev->dev);
-	if (ret < 0) {
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret) {
 		dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
-		pm_runtime_put_noidle(&pdev->dev);
 		goto exit_pm_disable;
 	}
 
 	reset_control_assert(tspi->rst);
 	udelay(2);
 	reset_control_deassert(tspi->rst);
 
+	spi_irq = platform_get_irq(pdev, 0);
+	tspi->irq = spi_irq;
+	ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
+				   tegra_slink_isr_thread, IRQF_ONESHOT,
+				   dev_name(&pdev->dev), tspi);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
+			tspi->irq);
+		goto exit_pm_put;
+	}
+
 	tspi->def_command_reg  = SLINK_M_S;
 	tspi->def_command2_reg = SLINK_CS_ACTIVE_BETWEEN;
 	tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
 	tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
-	pm_runtime_put(&pdev->dev);
 
 	master->dev.of_node = pdev->dev.of_node;
 	ret = devm_spi_register_master(&pdev->dev, master);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "can not register to master err %d\n", ret);
-		goto exit_pm_disable;
+		goto exit_free_irq;
 	}
+
+	pm_runtime_put(&pdev->dev);
+
 	return ret;
 
+exit_free_irq:
+	free_irq(spi_irq, tspi);
+exit_pm_put:
+	pm_runtime_put(&pdev->dev);
 exit_pm_disable:
 	pm_runtime_disable(&pdev->dev);
-	if (!pm_runtime_status_suspended(&pdev->dev))
-		tegra_slink_runtime_suspend(&pdev->dev);
+
 	tegra_slink_deinit_dma_param(tspi, false);
 exit_rx_dma_free:
 	tegra_slink_deinit_dma_param(tspi, true);
-exit_free_irq:
-	free_irq(spi_irq, tspi);
-exit_clk_disable:
-	clk_disable(tspi->clk);
-exit_clk_unprepare:
-	clk_unprepare(tspi->clk);
 exit_free_master:
 	spi_master_put(master);
 	return ret;
@@ -1162,18 +1144,13 @@ static int tegra_slink_remove(struct platform_device *pdev)
 
 	free_irq(tspi->irq, tspi);
 
-	clk_disable(tspi->clk);
-	clk_unprepare(tspi->clk);
-
 	if (tspi->tx_dma_chan)
 		tegra_slink_deinit_dma_param(tspi, false);
 
 	if (tspi->rx_dma_chan)
 		tegra_slink_deinit_dma_param(tspi, true);
 
 	pm_runtime_disable(&pdev->dev);
-	if (!pm_runtime_status_suspended(&pdev->dev))
-		tegra_slink_runtime_suspend(&pdev->dev);
 
 	return 0;
 }