Merge patch series "Add R-Car CAN-FD suspend/resume support"

Biju <biju.das.au@gmail.com> says:

From: Biju Das <biju.das.jz@bp.renesas.com>

This patch series adds proper suspend/resume support to the Renesas
R-Car CAN-FD controller driver, after the customary cleanups and fixes.
It aims to fix CAN-FD operation after resume from s2ram on systems where
PSCI powers down the SoC.

This patch series has been tested on RZ/G3E SMARC EVK and RZ/G2L SMARC
EVK.

This patch series depend upon [1]
[1] https://lore.kernel.org/all/20251123112326.128448-1-biju.das.jz@bp.renesas.com/

v2->v3:
 * Updated commit header and description for patch#3
 * Collected tags.
v1->v2:
 * Added logs from RZ/G3E
 * Collected tags.
 * Moved enabling of RAM clk from probe().
 * Added RAM clk handling in rcar_canfd_global_{,de}init().
 * Fixed the typo in error path of rcar_canfd_resume().

Logs from RZ/G3E:
root@smarc-rzg3e:~# /canfd_t_003_all.sh
 [INFO] Testing can0<->can1 with bitrate 1000000 and dbitrate 4000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
[  541.705921] can: controller area network core
[  541.710369] NET: Registered PF_CAN protocol family
[  541.753974] can: raw protocol
 [INFO] Testing can0 as producer and can1 as consumer
 [INFO] Testing can0<->can1 with bitrate 500000 and dbitrate 2000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer
 [INFO] Testing can0<->can1 with bitrate 250000 and dbitrate 1000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer

EXIT|PASS|canfd_t_003.sh|[00:00:25] ||

bind/unbind
----------
[  566.821475] rcar_canfd 12440000.can: can_clk rate is 80000000
[  566.828076] rcar_canfd 12440000.can: device registered (channel 1)
[  566.834361] rcar_canfd 12440000.can: can_clk rate is 80000000
[  566.841842] rcar_canfd 12440000.can: device registered (channel 4)
[  566.848093] rcar_canfd 12440000.can: global operational state (canfd clk, fd mode)
 [INFO] Testing can0<->can1 with bitrate 1000000 and dbitrate 4000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer
 [INFO] Testing can0<->can1 with bitrate 500000 and dbitrate 2000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer
 [INFO] Testing can0<->can1 with bitrate 250000 and dbitrate 1000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer

EXIT|PASS|canfd_t_003.sh|[00:00:25] ||

s2idle
-----
[  592.182479] PM: suspend entry (s2idle)
[  592.187031] Filesystems sync: 0.000 seconds
[  592.193221] Freezing user space processes
[  592.199425] Freezing user space processes completed (elapsed 0.002 seconds)
[  592.206450] OOM killer disabled.
[  592.209843] Freezing remaining freezable tasks
[  592.215775] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[  592.223247] printk: Suspending console(s) (use no_console_suspend to debug)
[  592.260524] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[  592.322759] renesas-gbeth 15c30000.ethernet end0: Link is Down
[  596.070955] dwmac4: Master AXI performs any burst length
[  596.072307] renesas-gbeth 15c30000.ethernet end0: No Safety Features support found
[  596.072376] renesas-gbeth 15c30000.ethernet end0: IEEE 1588-2008 Advanced Timestamp supported
[  596.077470] renesas-gbeth 15c30000.ethernet end0: configuring for phy/rgmii-id link mode
[  596.087503] dwmac4: Master AXI performs any burst length
[  596.088817] renesas-gbeth 15c40000.ethernet end1: No Safety Features support found
[  596.088881] renesas-gbeth 15c40000.ethernet end1: IEEE 1588-2008 Advanced Timestamp supported
[  596.093997] renesas-gbeth 15c40000.ethernet end1: configuring for phy/rgmii-id link mode
[  596.141986] usb usb1: root hub lost power or was reset
[  596.142031] usb usb2: root hub lost power or was reset
[  598.304525] usb 2-1: reset SuperSpeed Plus Gen 2x1 USB device number 2 using xhci-renesas-hcd
[  598.414846] OOM killer enabled.
[  598.418002] Restarting tasks: Starting
[  598.422518] Restarting tasks: Done
[  598.425999] random: crng reseeded on system resumption
[  598.431248] PM: suspend exit
[  598.661875] renesas-gbeth 15c30000.ethernet end0: Link is Up - 1Gbps/Full - flow control rx/tx
 [INFO] Testing can0<->can1 with bitrate 1000000 and dbitrate 4000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer
 [INFO] Testing can0<->can1 with bitrate 500000 and dbitrate 2000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer
 [INFO] Testing can0<->can1 with bitrate 250000 and dbitrate 1000000
 [INFO] Bringing down can0 can1
 [INFO] Bringing up can0 can1
 [INFO] Testing can1 as producer and can0 as consumer
 [INFO] Testing can0 as producer and can1 as consumer

EXIT|PASS|canfd_t_003.sh|[00:00:25] ||

Link: https://patch.msgid.link/20251124102837.106973-1-biju.das.jz@bp.renesas.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 168 insertions, 78 deletions

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 49ab65274b51..ce75948e6af6 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -468,6 +468,7 @@ struct rcar_canfd_global {
 	struct platform_device *pdev;	/* Respective platform device */
 	struct clk *clkp;		/* Peripheral clock */
 	struct clk *can_clk;		/* fCAN clock */
+	struct clk *clk_ram;		/* Clock RAM */
 	unsigned long channels_mask;	/* Enabled channels mask */
 	bool extclk;			/* CANFD or Ext clock */
 	bool fdmode;			/* CAN FD or Classical CAN only mode */
@@ -1569,8 +1570,8 @@ static int rcar_canfd_close(struct net_device *ndev)
 	netif_stop_queue(ndev);
 	rcar_canfd_stop(ndev);
 	napi_disable(&priv->napi);
-	clk_disable_unprepare(gpriv->can_clk);
 	close_candev(ndev);
+	clk_disable_unprepare(gpriv->can_clk);
 	phy_power_off(priv->transceiver);
 	return 0;
 }
@@ -1960,22 +1961,120 @@ static void rcar_canfd_channel_remove(struct rcar_canfd_global *gpriv, u32 ch)
 	}
 }
 
+static int rcar_canfd_global_init(struct rcar_canfd_global *gpriv)
+{
+	struct device *dev = &gpriv->pdev->dev;
+	u32 rule_entry = 0;
+	u32 ch, sts;
+	int err;
+
+	err = reset_control_reset(gpriv->rstc1);
+	if (err)
+		return err;
+
+	err = reset_control_reset(gpriv->rstc2);
+	if (err)
+		goto fail_reset1;
+
+	/* Enable peripheral clock for register access */
+	err = clk_prepare_enable(gpriv->clkp);
+	if (err) {
+		dev_err(dev, "failed to enable peripheral clock: %pe\n",
+			ERR_PTR(err));
+		goto fail_reset2;
+	}
+
+	/* Enable RAM clock */
+	err = clk_prepare_enable(gpriv->clk_ram);
+	if (err) {
+		dev_err(dev,
+			"failed to enable RAM clock, error %d\n", err);
+		goto fail_clk;
+	}
+
+	err = rcar_canfd_reset_controller(gpriv);
+	if (err) {
+		dev_err(dev, "reset controller failed: %pe\n", ERR_PTR(err));
+		goto fail_ram_clk;
+	}
+
+	/* Controller in Global reset & Channel reset mode */
+	rcar_canfd_configure_controller(gpriv);
+
+	/* Configure per channel attributes */
+	for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
+		/* Configure Channel's Rx fifo */
+		rcar_canfd_configure_rx(gpriv, ch);
+
+		/* Configure Channel's Tx (Common) fifo */
+		rcar_canfd_configure_tx(gpriv, ch);
+
+		/* Configure receive rules */
+		rcar_canfd_configure_afl_rules(gpriv, ch, rule_entry);
+		rule_entry += RCANFD_CHANNEL_NUMRULES;
+	}
+
+	/* Configure common interrupts */
+	rcar_canfd_enable_global_interrupts(gpriv);
+
+	/* Start Global operation mode */
+	rcar_canfd_update_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GMDC_MASK,
+			      RCANFD_GCTR_GMDC_GOPM);
+
+	/* Verify mode change */
+	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
+				 !(sts & RCANFD_GSTS_GNOPM), 2, 500000);
+	if (err) {
+		dev_err(dev, "global operational mode failed\n");
+		goto fail_mode;
+	}
+
+	return 0;
+
+fail_mode:
+	rcar_canfd_disable_global_interrupts(gpriv);
+fail_ram_clk:
+	clk_disable_unprepare(gpriv->clk_ram);
+fail_clk:
+	clk_disable_unprepare(gpriv->clkp);
+fail_reset2:
+	reset_control_assert(gpriv->rstc2);
+fail_reset1:
+	reset_control_assert(gpriv->rstc1);
+	return err;
+}
+
+static void rcar_canfd_global_deinit(struct rcar_canfd_global *gpriv, bool full)
+{
+	rcar_canfd_disable_global_interrupts(gpriv);
+
+	if (full) {
+		rcar_canfd_reset_controller(gpriv);
+
+		/* Enter global sleep mode */
+		rcar_canfd_set_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GSLPR);
+	}
+
+	clk_disable_unprepare(gpriv->clk_ram);
+	clk_disable_unprepare(gpriv->clkp);
+	reset_control_assert(gpriv->rstc2);
+	reset_control_assert(gpriv->rstc1);
+}
+
 static int rcar_canfd_probe(struct platform_device *pdev)
 {
 	struct phy *transceivers[RCANFD_NUM_CHANNELS] = { NULL, };
 	const struct rcar_canfd_hw_info *info;
 	struct device *dev = &pdev->dev;
 	void __iomem *addr;
-	u32 sts, ch, fcan_freq;
 	struct rcar_canfd_global *gpriv;
 	struct device_node *of_child;
 	unsigned long channels_mask = 0;
 	int err, ch_irq, g_irq;
 	int g_err_irq, g_recc_irq;
-	u32 rule_entry = 0;
 	bool fdmode = true;			/* CAN FD only mode - default */
 	char name[9] = "channelX";
-	struct clk *clk_ram;
+	u32 ch, fcan_freq;
 	int i;
 
 	info = of_device_get_match_data(dev);
@@ -2065,10 +2164,10 @@ static int rcar_canfd_probe(struct platform_device *pdev)
 		gpriv->extclk = gpriv->info->external_clk;
 	}
 
-	clk_ram = devm_clk_get_optional_enabled(dev, "ram_clk");
-	if (IS_ERR(clk_ram))
-		return dev_err_probe(dev, PTR_ERR(clk_ram),
-				     "cannot get enabled ram clock\n");
+	gpriv->clk_ram = devm_clk_get_optional(dev, "ram_clk");
+	if (IS_ERR(gpriv->clk_ram))
+		return dev_err_probe(dev, PTR_ERR(gpriv->clk_ram),
+				     "cannot get ram clock\n");
 
 	addr = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(addr)) {
@@ -2117,59 +2216,9 @@ static int rcar_canfd_probe(struct platform_device *pdev)
 		}
 	}
 
-	err = reset_control_reset(gpriv->rstc1);
+	err = rcar_canfd_global_init(gpriv);
 	if (err)
-		goto fail_dev;
-	err = reset_control_reset(gpriv->rstc2);
-	if (err) {
-		reset_control_assert(gpriv->rstc1);
-		goto fail_dev;
-	}
-
-	/* Enable peripheral clock for register access */
-	err = clk_prepare_enable(gpriv->clkp);
-	if (err) {
-		dev_err(dev, "failed to enable peripheral clock: %pe\n",
-			ERR_PTR(err));
-		goto fail_reset;
-	}
-
-	err = rcar_canfd_reset_controller(gpriv);
-	if (err) {
-		dev_err(dev, "reset controller failed: %pe\n", ERR_PTR(err));
-		goto fail_clk;
-	}
-
-	/* Controller in Global reset & Channel reset mode */
-	rcar_canfd_configure_controller(gpriv);
-
-	/* Configure per channel attributes */
-	for_each_set_bit(ch, &gpriv->channels_mask, info->max_channels) {
-		/* Configure Channel's Rx fifo */
-		rcar_canfd_configure_rx(gpriv, ch);
-
-		/* Configure Channel's Tx (Common) fifo */
-		rcar_canfd_configure_tx(gpriv, ch);
-
-		/* Configure receive rules */
-		rcar_canfd_configure_afl_rules(gpriv, ch, rule_entry);
-		rule_entry += RCANFD_CHANNEL_NUMRULES;
-	}
-
-	/* Configure common interrupts */
-	rcar_canfd_enable_global_interrupts(gpriv);
-
-	/* Start Global operation mode */
-	rcar_canfd_update_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GMDC_MASK,
-			      RCANFD_GCTR_GMDC_GOPM);
-
-	/* Verify mode change */
-	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
-				 !(sts & RCANFD_GSTS_GNOPM), 2, 500000);
-	if (err) {
-		dev_err(dev, "global operational mode failed\n");
 		goto fail_mode;
-	}
 
 	for_each_set_bit(ch, &gpriv->channels_mask, info->max_channels) {
 		err = rcar_canfd_channel_probe(gpriv, ch, fcan_freq,
@@ -2188,12 +2237,7 @@ fail_channel:
 	for_each_set_bit(ch, &gpriv->channels_mask, info->max_channels)
 		rcar_canfd_channel_remove(gpriv, ch);
 fail_mode:
-	rcar_canfd_disable_global_interrupts(gpriv);
-fail_clk:
-	clk_disable_unprepare(gpriv->clkp);
-fail_reset:
-	reset_control_assert(gpriv->rstc1);
-	reset_control_assert(gpriv->rstc2);
+	rcar_canfd_global_deinit(gpriv, false);
 fail_dev:
 	return err;
 }
@@ -2203,33 +2247,79 @@ static void rcar_canfd_remove(struct platform_device *pdev)
 	struct rcar_canfd_global *gpriv = platform_get_drvdata(pdev);
 	u32 ch;
 
-	rcar_canfd_reset_controller(gpriv);
-	rcar_canfd_disable_global_interrupts(gpriv);
-
 	for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
 		rcar_canfd_disable_channel_interrupts(gpriv->ch[ch]);
 		rcar_canfd_channel_remove(gpriv, ch);
 	}
 
-	/* Enter global sleep mode */
-	rcar_canfd_set_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GSLPR);
-	clk_disable_unprepare(gpriv->clkp);
-	reset_control_assert(gpriv->rstc1);
-	reset_control_assert(gpriv->rstc2);
+	rcar_canfd_global_deinit(gpriv, true);
 }
 
-static int __maybe_unused rcar_canfd_suspend(struct device *dev)
+static int rcar_canfd_suspend(struct device *dev)
 {
+	struct rcar_canfd_global *gpriv = dev_get_drvdata(dev);
+	int err;
+	u32 ch;
+
+	for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
+		struct rcar_canfd_channel *priv = gpriv->ch[ch];
+		struct net_device *ndev = priv->ndev;
+
+		if (!netif_running(ndev))
+			continue;
+
+		netif_device_detach(ndev);
+
+		err = rcar_canfd_close(ndev);
+		if (err) {
+			netdev_err(ndev, "rcar_canfd_close() failed %pe\n",
+				   ERR_PTR(err));
+			return err;
+		}
+
+		priv->can.state = CAN_STATE_SLEEPING;
+	}
+
+	/* TODO Skip if wake-up (which is not yet supported) is enabled */
+	rcar_canfd_global_deinit(gpriv, false);
+
 	return 0;
 }
 
-static int __maybe_unused rcar_canfd_resume(struct device *dev)
+static int rcar_canfd_resume(struct device *dev)
 {
+	struct rcar_canfd_global *gpriv = dev_get_drvdata(dev);
+	int err;
+	u32 ch;
+
+	err = rcar_canfd_global_init(gpriv);
+	if (err) {
+		dev_err(dev, "rcar_canfd_global_init() failed %pe\n", ERR_PTR(err));
+		return err;
+	}
+
+	for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
+		struct rcar_canfd_channel *priv = gpriv->ch[ch];
+		struct net_device *ndev = priv->ndev;
+
+		if (!netif_running(ndev))
+			continue;
+
+		err = rcar_canfd_open(ndev);
+		if (err) {
+			netdev_err(ndev, "rcar_canfd_open() failed %pe\n",
+				   ERR_PTR(err));
+			return err;
+		}
+
+		netif_device_attach(ndev);
+	}
+
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(rcar_canfd_pm_ops, rcar_canfd_suspend,
-			 rcar_canfd_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(rcar_canfd_pm_ops, rcar_canfd_suspend,
+				rcar_canfd_resume);
 
 static const __maybe_unused struct of_device_id rcar_canfd_of_table[] = {
 	{ .compatible = "renesas,r8a779a0-canfd", .data = &rcar_gen4_hw_info },
@@ -2246,7 +2336,7 @@ static struct platform_driver rcar_canfd_driver = {
 	.driver = {
 		.name = RCANFD_DRV_NAME,
 		.of_match_table = of_match_ptr(rcar_canfd_of_table),
-		.pm = &rcar_canfd_pm_ops,
+		.pm = pm_sleep_ptr(&rcar_canfd_pm_ops),
 	},
 	.probe = rcar_canfd_probe,
 	.remove = rcar_canfd_remove,