i3c: master: svc: add runtime pm support

Add runtime pm support to dynamically manage the clock.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211227074529.1660398-7-xiaoning.wang@nxp.com

drivers/i3c/master/svc-i3c-master.c

@@ -17,7 +17,9 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 
 /* Master Mode Registers */
 #define SVC_I3C_MCONFIG      0x000
@@ -119,6 +121,7 @@
 #define   SVC_MDYNADDR_ADDR(x) FIELD_PREP(GENMASK(7, 1), (x))
 
 #define SVC_I3C_MAX_DEVS 32
+#define SVC_I3C_PM_TIMEOUT_MS 1000
 
 /* This parameter depends on the implementation and may be tuned */
 #define SVC_I3C_FIFO_SIZE 16
@@ -480,10 +483,20 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
 	u32 ppbaud, pplow, odhpp, odbaud, odstop, i2cbaud, reg;
 	int ret;
 
+	ret = pm_runtime_resume_and_get(master->dev);
+	if (ret < 0) {
+		dev_err(master->dev,
+			"<%s> cannot resume i3c bus master, err: %d\n",
+			__func__, ret);
+		return ret;
+	}
+
 	/* Timings derivation */
 	fclk_rate = clk_get_rate(master->fclk);
-	if (!fclk_rate)
-		return -EINVAL;
+	if (!fclk_rate) {
+		ret = -EINVAL;
+		goto rpm_out;
+	}
 
 	fclk_period_ns = DIV_ROUND_UP(1000000000, fclk_rate);
 
@@ -527,7 +540,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
 		odstop = 1;
 		break;
 	default:
-		return -EINVAL;
+		goto rpm_out;
 	}
 
 	reg = SVC_I3C_MCONFIG_MASTER_EN |
@@ -545,7 +558,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
 	/* Master core's registration */
 	ret = i3c_master_get_free_addr(m, 0);
 	if (ret < 0)
-		return ret;
+		goto rpm_out;
 
 	info.dyn_addr = ret;
 
@@ -554,21 +567,35 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m)
 
 	ret = i3c_master_set_info(&master->base, &info);
 	if (ret)
-		return ret;
+		goto rpm_out;
 
 	svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
 
-	return 0;
+rpm_out:
+	pm_runtime_mark_last_busy(master->dev);
+	pm_runtime_put_autosuspend(master->dev);
+
+	return ret;
 }
 
 static void svc_i3c_master_bus_cleanup(struct i3c_master_controller *m)
 {
 	struct svc_i3c_master *master = to_svc_i3c_master(m);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(master->dev);
+	if (ret < 0) {
+		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
+		return;
+	}
 
 	svc_i3c_master_disable_interrupts(master);
 
 	/* Disable master */
 	writel(0, master->regs + SVC_I3C_MCONFIG);
+
+	pm_runtime_mark_last_busy(master->dev);
+	pm_runtime_put_autosuspend(master->dev);
 }
 
 static int svc_i3c_master_reserve_slot(struct svc_i3c_master *master)
@@ -867,31 +894,36 @@ static int svc_i3c_master_do_daa(struct i3c_master_controller *m)
 	unsigned int dev_nb;
 	int ret, i;
 
+	ret = pm_runtime_resume_and_get(master->dev);
+	if (ret < 0) {
+		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
+		return ret;
+	}
+
 	spin_lock_irqsave(&master->xferqueue.lock, flags);
 	ret = svc_i3c_master_do_daa_locked(master, addrs, &dev_nb);
 	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
-	if (ret)
-		goto emit_stop;
+	if (ret) {
+		svc_i3c_master_emit_stop(master);
+		svc_i3c_master_clear_merrwarn(master);
+		goto rpm_out;
+	}
 
 	/* Register all devices who participated to the core */
 	for (i = 0; i < dev_nb; i++) {
 		ret = i3c_master_add_i3c_dev_locked(m, addrs[i]);
 		if (ret)
-			return ret;
+			goto rpm_out;
 	}
 
 	/* Configure IBI auto-rules */
 	ret = svc_i3c_update_ibirules(master);
-	if (ret) {
+	if (ret)
 		dev_err(master->dev, "Cannot handle such a list of devices");
-		return ret;
-	}
-
-	return 0;
 
-emit_stop:
-	svc_i3c_master_emit_stop(master);
-	svc_i3c_master_clear_merrwarn(master);
+rpm_out:
+	pm_runtime_mark_last_busy(master->dev);
+	pm_runtime_put_autosuspend(master->dev);
 
 	return ret;
 }
@@ -1060,6 +1092,12 @@ static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
 	if (!xfer)
 		return;
 
+	ret = pm_runtime_resume_and_get(master->dev);
+	if (ret < 0) {
+		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
+		return;
+	}
+
 	svc_i3c_master_clear_merrwarn(master);
 	svc_i3c_master_flush_fifo(master);
 
@@ -1074,6 +1112,9 @@ static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
 			break;
 	}
 
+	pm_runtime_mark_last_busy(master->dev);
+	pm_runtime_put_autosuspend(master->dev);
+
 	xfer->ret = ret;
 	complete(&xfer->comp);
 
@@ -1350,6 +1391,14 @@ static void svc_i3c_master_free_ibi(struct i3c_dev_desc *dev)
 static int svc_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
 {
 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
+	struct svc_i3c_master *master = to_svc_i3c_master(m);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(master->dev);
+	if (ret < 0) {
+		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);
+		return ret;
+	}
 
 	return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
 }
@@ -1357,8 +1406,15 @@ static int svc_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
 static int svc_i3c_master_disable_ibi(struct i3c_dev_desc *dev)
 {
 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
+	struct svc_i3c_master *master = to_svc_i3c_master(m);
+	int ret;
+
+	ret = i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
 
-	return i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
+	pm_runtime_mark_last_busy(master->dev);
+	pm_runtime_put_autosuspend(master->dev);
+
+	return ret;
 }
 
 static void svc_i3c_master_recycle_ibi_slot(struct i3c_dev_desc *dev,
@@ -1389,6 +1445,37 @@ static const struct i3c_master_controller_ops svc_i3c_master_ops = {
 	.disable_ibi = svc_i3c_master_disable_ibi,
 };
 
+static int svc_i3c_master_prepare_clks(struct svc_i3c_master *master)
+{
+	int ret = 0;
+
+	ret = clk_prepare_enable(master->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(master->fclk);
+	if (ret) {
+		clk_disable_unprepare(master->pclk);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(master->sclk);
+	if (ret) {
+		clk_disable_unprepare(master->pclk);
+		clk_disable_unprepare(master->fclk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void svc_i3c_master_unprepare_clks(struct svc_i3c_master *master)
+{
+	clk_disable_unprepare(master->pclk);
+	clk_disable_unprepare(master->fclk);
+	clk_disable_unprepare(master->sclk);
+}
+
 static int svc_i3c_master_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1421,24 +1508,16 @@ static int svc_i3c_master_probe(struct platform_device *pdev)
 
 	master->dev = dev;
 
-	ret = clk_prepare_enable(master->pclk);
+	ret = svc_i3c_master_prepare_clks(master);
 	if (ret)
 		return ret;
 
-	ret = clk_prepare_enable(master->fclk);
-	if (ret)
-		goto err_disable_pclk;
-
-	ret = clk_prepare_enable(master->sclk);
-	if (ret)
-		goto err_disable_fclk;
-
 	INIT_WORK(&master->hj_work, svc_i3c_master_hj_work);
 	INIT_WORK(&master->ibi_work, svc_i3c_master_ibi_work);
 	ret = devm_request_irq(dev, master->irq, svc_i3c_master_irq_handler,
 			       IRQF_NO_SUSPEND, "svc-i3c-irq", master);
 	if (ret)
-		goto err_disable_sclk;
+		goto err_disable_clks;
 
 	master->free_slots = GENMASK(SVC_I3C_MAX_DEVS - 1, 0);
 
@@ -1452,29 +1531,38 @@ static int svc_i3c_master_probe(struct platform_device *pdev)
 					 GFP_KERNEL);
 	if (!master->ibi.slots) {
 		ret = -ENOMEM;
-		goto err_disable_sclk;
+		goto err_disable_clks;
 	}
 
 	platform_set_drvdata(pdev, master);
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, SVC_I3C_PM_TIMEOUT_MS);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
 	svc_i3c_master_reset(master);
 
 	/* Register the master */
 	ret = i3c_master_register(&master->base, &pdev->dev,
 				  &svc_i3c_master_ops, false);
 	if (ret)
-		goto err_disable_sclk;
+		goto rpm_disable;
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
 
 	return 0;
 
-err_disable_sclk:
-	clk_disable_unprepare(master->sclk);
+rpm_disable:
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
-err_disable_fclk:
-	clk_disable_unprepare(master->fclk);
-
-err_disable_pclk:
-	clk_disable_unprepare(master->pclk);
+err_disable_clks:
+	svc_i3c_master_unprepare_clks(master);
 
 	return ret;
 }
@@ -1488,13 +1576,40 @@ static int svc_i3c_master_remove(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	clk_disable_unprepare(master->pclk);
-	clk_disable_unprepare(master->fclk);
-	clk_disable_unprepare(master->sclk);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
 	return 0;
 }
 
+static int __maybe_unused svc_i3c_runtime_suspend(struct device *dev)
+{
+	struct svc_i3c_master *master = dev_get_drvdata(dev);
+
+	svc_i3c_master_unprepare_clks(master);
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int __maybe_unused svc_i3c_runtime_resume(struct device *dev)
+{
+	struct svc_i3c_master *master = dev_get_drvdata(dev);
+	int ret = 0;
+
+	pinctrl_pm_select_default_state(dev);
+	svc_i3c_master_prepare_clks(master);
+
+	return ret;
+}
+
+static const struct dev_pm_ops svc_i3c_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(svc_i3c_runtime_suspend,
+			   svc_i3c_runtime_resume, NULL)
+};
+
 static const struct of_device_id svc_i3c_master_of_match_tbl[] = {
 	{ .compatible = "silvaco,i3c-master" },
 	{ /* sentinel */ },
@@ -1506,6 +1621,7 @@ static struct platform_driver svc_i3c_master = {
 	.driver = {
 		.name = "silvaco-i3c-master",
 		.of_match_table = svc_i3c_master_of_match_tbl,
+		.pm = &svc_i3c_pm_ops,
 	},
 };
 module_platform_driver(svc_i3c_master);