1 files changed, 134 insertions, 95 deletions

diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
index f3d8d53ab84d..b03310c0830d 100644
--- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
+++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
@@ -11,6 +11,8 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/dev_printk.h>
 #include <linux/interrupt.h>
 #include <linux/fs.h>
 #include <linux/kfifo.h>
@@ -18,36 +20,33 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/poll.h>
 #include <linux/regmap.h>
 
 #define DEVICE_NAME	"aspeed-lpc-snoop"
 
-#define NUM_SNOOP_CHANNELS 2
 #define SNOOP_FIFO_SIZE 2048
 
-#define HICR5	0x0
+#define HICR5	0x80
 #define HICR5_EN_SNP0W		BIT(0)
 #define HICR5_ENINT_SNP0W	BIT(1)
 #define HICR5_EN_SNP1W		BIT(2)
 #define HICR5_ENINT_SNP1W	BIT(3)
-
-#define HICR6	0x4
+#define HICR6	0x84
 #define HICR6_STR_SNP0W		BIT(0)
 #define HICR6_STR_SNP1W		BIT(1)
-#define SNPWADR	0x10
+#define SNPWADR	0x90
 #define SNPWADR_CH0_MASK	GENMASK(15, 0)
 #define SNPWADR_CH0_SHIFT	0
 #define SNPWADR_CH1_MASK	GENMASK(31, 16)
 #define SNPWADR_CH1_SHIFT	16
-#define SNPWDR	0x14
+#define SNPWDR	0x94
 #define SNPWDR_CH0_MASK		GENMASK(7, 0)
 #define SNPWDR_CH0_SHIFT	0
 #define SNPWDR_CH1_MASK		GENMASK(15, 8)
 #define SNPWDR_CH1_SHIFT	8
-#define HICRB	0x80
+#define HICRB	0x100
 #define HICRB_ENSNP0D		BIT(14)
 #define HICRB_ENSNP1D		BIT(15)
 
@@ -58,7 +57,23 @@ struct aspeed_lpc_snoop_model_data {
 	unsigned int has_hicrb_ensnp;
 };
 
+enum aspeed_lpc_snoop_index {
+	ASPEED_LPC_SNOOP_INDEX_0 = 0,
+	ASPEED_LPC_SNOOP_INDEX_1 = 1,
+	ASPEED_LPC_SNOOP_INDEX_MAX = ASPEED_LPC_SNOOP_INDEX_1,
+};
+
+struct aspeed_lpc_snoop_channel_cfg {
+	enum aspeed_lpc_snoop_index index;
+	u32 hicr5_en;
+	u32 snpwadr_mask;
+	u32 snpwadr_shift;
+	u32 hicrb_en;
+};
+
 struct aspeed_lpc_snoop_channel {
+	const struct aspeed_lpc_snoop_channel_cfg *cfg;
+	bool enabled;
 	struct kfifo		fifo;
 	wait_queue_head_t	wq;
 	struct miscdevice	miscdev;
@@ -67,7 +82,25 @@ struct aspeed_lpc_snoop_channel {
 struct aspeed_lpc_snoop {
 	struct regmap		*regmap;
 	int			irq;
-	struct aspeed_lpc_snoop_channel chan[NUM_SNOOP_CHANNELS];
+	struct clk		*clk;
+	struct aspeed_lpc_snoop_channel chan[ASPEED_LPC_SNOOP_INDEX_MAX + 1];
+};
+
+static const struct aspeed_lpc_snoop_channel_cfg channel_cfgs[ASPEED_LPC_SNOOP_INDEX_MAX + 1] = {
+	{
+		.index = ASPEED_LPC_SNOOP_INDEX_0,
+		.hicr5_en = HICR5_EN_SNP0W | HICR5_ENINT_SNP0W,
+		.snpwadr_mask = SNPWADR_CH0_MASK,
+		.snpwadr_shift = SNPWADR_CH0_SHIFT,
+		.hicrb_en = HICRB_ENSNP0D,
+	},
+	{
+		.index = ASPEED_LPC_SNOOP_INDEX_1,
+		.hicr5_en = HICR5_EN_SNP1W | HICR5_ENINT_SNP1W,
+		.snpwadr_mask = SNPWADR_CH1_MASK,
+		.snpwadr_shift = SNPWADR_CH1_SHIFT,
+		.hicrb_en = HICRB_ENSNP1D,
+	},
 };
 
 static struct aspeed_lpc_snoop_channel *snoop_file_to_chan(struct file *file)
@@ -93,8 +126,10 @@ static ssize_t snoop_file_read(struct file *file, char __user *buffer,
 			return -EINTR;
 	}
 	ret = kfifo_to_user(&chan->fifo, buffer, count, &copied);
+	if (ret)
+		return ret;
 
-	return ret ? ret : copied;
+	return copied;
 }
 
 static __poll_t snoop_file_poll(struct file *file,
@@ -164,7 +199,7 @@ static int aspeed_lpc_snoop_config_irq(struct aspeed_lpc_snoop *lpc_snoop,
 	int rc;
 
 	lpc_snoop->irq = platform_get_irq(pdev, 0);
-	if (!lpc_snoop->irq)
+	if (lpc_snoop->irq < 0)
 		return -ENODEV;
 
 	rc = devm_request_irq(dev, lpc_snoop->irq,
@@ -179,86 +214,88 @@ static int aspeed_lpc_snoop_config_irq(struct aspeed_lpc_snoop *lpc_snoop,
 	return 0;
 }
 
-static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
-				   struct device *dev,
-				   int channel, u16 lpc_port)
+__attribute__((nonnull))
+static int aspeed_lpc_enable_snoop(struct device *dev,
+				    struct aspeed_lpc_snoop *lpc_snoop,
+				    struct aspeed_lpc_snoop_channel *channel,
+				    const struct aspeed_lpc_snoop_channel_cfg *cfg,
+				    u16 lpc_port)
 {
+	const struct aspeed_lpc_snoop_model_data *model_data;
 	int rc = 0;
-	u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
-	const struct aspeed_lpc_snoop_model_data *model_data =
-		of_device_get_match_data(dev);
-
-	init_waitqueue_head(&lpc_snoop->chan[channel].wq);
-	/* Create FIFO datastructure */
-	rc = kfifo_alloc(&lpc_snoop->chan[channel].fifo,
-			 SNOOP_FIFO_SIZE, GFP_KERNEL);
+
+	if (WARN_ON(channel->enabled))
+		return -EBUSY;
+
+	init_waitqueue_head(&channel->wq);
+
+	channel->cfg = cfg;
+	channel->miscdev.minor = MISC_DYNAMIC_MINOR;
+	channel->miscdev.fops = &snoop_fops;
+	channel->miscdev.parent = dev;
+
+	channel->miscdev.name =
+		devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, cfg->index);
+	if (!channel->miscdev.name)
+		return -ENOMEM;
+
+	rc = kfifo_alloc(&channel->fifo, SNOOP_FIFO_SIZE, GFP_KERNEL);
 	if (rc)
 		return rc;
 
-	lpc_snoop->chan[channel].miscdev.minor = MISC_DYNAMIC_MINOR;
-	lpc_snoop->chan[channel].miscdev.name =
-		devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, channel);
-	lpc_snoop->chan[channel].miscdev.fops = &snoop_fops;
-	lpc_snoop->chan[channel].miscdev.parent = dev;
-	rc = misc_register(&lpc_snoop->chan[channel].miscdev);
+	rc = misc_register(&channel->miscdev);
 	if (rc)
-		return rc;
+		goto err_free_fifo;
 
 	/* Enable LPC snoop channel at requested port */
-	switch (channel) {
-	case 0:
-		hicr5_en = HICR5_EN_SNP0W | HICR5_ENINT_SNP0W;
-		snpwadr_mask = SNPWADR_CH0_MASK;
-		snpwadr_shift = SNPWADR_CH0_SHIFT;
-		hicrb_en = HICRB_ENSNP0D;
-		break;
-	case 1:
-		hicr5_en = HICR5_EN_SNP1W | HICR5_ENINT_SNP1W;
-		snpwadr_mask = SNPWADR_CH1_MASK;
-		snpwadr_shift = SNPWADR_CH1_SHIFT;
-		hicrb_en = HICRB_ENSNP1D;
-		break;
-	default:
-		return -EINVAL;
-	}
+	regmap_set_bits(lpc_snoop->regmap, HICR5, cfg->hicr5_en);
+	regmap_update_bits(lpc_snoop->regmap, SNPWADR, cfg->snpwadr_mask,
+			   lpc_port << cfg->snpwadr_shift);
 
-	regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
-	regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,
-			   lpc_port << snpwadr_shift);
-	if (model_data->has_hicrb_ensnp)
-		regmap_update_bits(lpc_snoop->regmap, HICRB,
-				hicrb_en, hicrb_en);
+	model_data = of_device_get_match_data(dev);
+	if (model_data && model_data->has_hicrb_ensnp)
+		regmap_set_bits(lpc_snoop->regmap, HICRB, cfg->hicrb_en);
 
+	channel->enabled = true;
+
+	return 0;
+
+err_free_fifo:
+	kfifo_free(&channel->fifo);
 	return rc;
 }
 
+__attribute__((nonnull))
 static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
-				     int channel)
+				     struct aspeed_lpc_snoop_channel *channel)
 {
-	switch (channel) {
-	case 0:
-		regmap_update_bits(lpc_snoop->regmap, HICR5,
-				   HICR5_EN_SNP0W | HICR5_ENINT_SNP0W,
-				   0);
-		break;
-	case 1:
-		regmap_update_bits(lpc_snoop->regmap, HICR5,
-				   HICR5_EN_SNP1W | HICR5_ENINT_SNP1W,
-				   0);
-		break;
-	default:
+	if (!channel->enabled)
 		return;
-	}
 
-	kfifo_free(&lpc_snoop->chan[channel].fifo);
-	misc_deregister(&lpc_snoop->chan[channel].miscdev);
+	/* Disable interrupts along with the device */
+	regmap_clear_bits(lpc_snoop->regmap, HICR5, channel->cfg->hicr5_en);
+
+	channel->enabled = false;
+	/* Consider improving safety wrt concurrent reader(s) */
+	misc_deregister(&channel->miscdev);
+	kfifo_free(&channel->fifo);
+}
+
+static void aspeed_lpc_snoop_remove(struct platform_device *pdev)
+{
+	struct aspeed_lpc_snoop *lpc_snoop = dev_get_drvdata(&pdev->dev);
+
+	/* Disable both snoop channels */
+	aspeed_lpc_disable_snoop(lpc_snoop, &lpc_snoop->chan[0]);
+	aspeed_lpc_disable_snoop(lpc_snoop, &lpc_snoop->chan[1]);
 }
 
 static int aspeed_lpc_snoop_probe(struct platform_device *pdev)
 {
 	struct aspeed_lpc_snoop *lpc_snoop;
+	struct device_node *np;
 	struct device *dev;
-	u32 port;
+	int idx;
 	int rc;
 
 	dev = &pdev->dev;
@@ -267,49 +304,49 @@ static int aspeed_lpc_snoop_probe(struct platform_device *pdev)
 	if (!lpc_snoop)
 		return -ENOMEM;
 
-	lpc_snoop->regmap = syscon_node_to_regmap(
-			pdev->dev.parent->of_node);
-	if (IS_ERR(lpc_snoop->regmap)) {
-		dev_err(dev, "Couldn't get regmap\n");
+	np = pdev->dev.parent->of_node;
+	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
+	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
+	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
+		dev_err(dev, "unsupported LPC device binding\n");
 		return -ENODEV;
 	}
 
+	lpc_snoop->regmap = syscon_node_to_regmap(np);
+	if (IS_ERR(lpc_snoop->regmap))
+		return dev_err_probe(dev, PTR_ERR(lpc_snoop->regmap), "Couldn't get regmap\n");
+
 	dev_set_drvdata(&pdev->dev, lpc_snoop);
 
-	rc = of_property_read_u32_index(dev->of_node, "snoop-ports", 0, &port);
-	if (rc) {
-		dev_err(dev, "no snoop ports configured\n");
-		return -ENODEV;
-	}
+	lpc_snoop->clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(lpc_snoop->clk))
+		return dev_err_probe(dev, PTR_ERR(lpc_snoop->clk), "couldn't get clock");
 
 	rc = aspeed_lpc_snoop_config_irq(lpc_snoop, pdev);
 	if (rc)
 		return rc;
 
-	rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 0, port);
-	if (rc)
-		return rc;
+	static_assert(ARRAY_SIZE(channel_cfgs) == ARRAY_SIZE(lpc_snoop->chan),
+		"Broken implementation assumption regarding cfg count");
+	for (idx = ASPEED_LPC_SNOOP_INDEX_0; idx <= ASPEED_LPC_SNOOP_INDEX_MAX; idx++) {
+		u32 port;
 
-	/* Configuration of 2nd snoop channel port is optional */
-	if (of_property_read_u32_index(dev->of_node, "snoop-ports",
-				       1, &port) == 0) {
-		rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 1, port);
+		rc = of_property_read_u32_index(dev->of_node, "snoop-ports", idx, &port);
 		if (rc)
-			aspeed_lpc_disable_snoop(lpc_snoop, 0);
+			break;
+
+		rc = aspeed_lpc_enable_snoop(dev, lpc_snoop, &lpc_snoop->chan[idx],
+					     &channel_cfgs[idx], port);
+		if (rc)
+			goto cleanup_channels;
 	}
 
-	return rc;
-}
+	return idx == ASPEED_LPC_SNOOP_INDEX_0 ? -ENODEV : 0;
 
-static int aspeed_lpc_snoop_remove(struct platform_device *pdev)
-{
-	struct aspeed_lpc_snoop *lpc_snoop = dev_get_drvdata(&pdev->dev);
+cleanup_channels:
+	aspeed_lpc_snoop_remove(pdev);
 
-	/* Disable both snoop channels */
-	aspeed_lpc_disable_snoop(lpc_snoop, 0);
-	aspeed_lpc_disable_snoop(lpc_snoop, 1);
-
-	return 0;
+	return rc;
 }
 
 static const struct aspeed_lpc_snoop_model_data ast2400_model_data = {
@@ -325,6 +362,8 @@ static const struct of_device_id aspeed_lpc_snoop_match[] = {
 	  .data = &ast2400_model_data },
 	{ .compatible = "aspeed,ast2500-lpc-snoop",
 	  .data = &ast2500_model_data },
+	{ .compatible = "aspeed,ast2600-lpc-snoop",
+	  .data = &ast2500_model_data },
 	{ },
 };