[PATCH 2/2] remoteproc: imx_rproc: support remote cores booted before Linux Kernel

["Peng Fan (OSS)" <peng.fan@xxxxxxxxxxx>]

From: Peng Fan <peng.fan@xxxxxxx>

Support remote cores booted before Linux Kernel booting.

Add rsc_table to hold the resource table published by remote cores
Add attach hook
Add imx_rproc_detect_mode to detect remote cores' working mode, and if
remote cores are booted before booting Linux Kernel, parse the memory
regions and initialize the table_ptr, table_sz, cached_table.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
 drivers/remoteproc/imx_rproc.c | 64 ++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index 24275429a7cc..fdaaf7599cc8 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -74,6 +74,16 @@ struct imx_rproc_att {
 	int flags;
 };
 
+enum imx_rproc_mode {
+	/* Linux load/kick remote core */
+	IMX_RPROC_NORMAL,
+	/*
+	 * remote core booted before kicking Linux, and remote core
+	 * could be stopped & restarted by Linux
+	 */
+	IMX_RPROC_EARLY_BOOT,
+};
+
 struct imx_rproc_dcfg {
 	u32				src_reg;
 	u32				src_mask;
@@ -95,6 +105,8 @@ struct imx_rproc {
 	struct mbox_chan		*rx_ch;
 	struct work_struct		rproc_work;
 	struct workqueue_struct		*workqueue;
+	enum imx_rproc_mode		mode;
+	void __iomem			*rsc_table;
 };
 
 static const struct imx_rproc_att imx_rproc_att_imx8mq[] = {
@@ -229,6 +241,9 @@ static int imx_rproc_stop(struct rproc *rproc)
 	if (ret)
 		dev_err(dev, "Failed to stop M4!\n");
 
+	if (priv->mode == IMX_RPROC_EARLY_BOOT)
+		priv->mode = IMX_RPROC_NORMAL;
+
 	return ret;
 }
 
@@ -398,9 +413,15 @@ static void imx_rproc_kick(struct rproc *rproc, int vqid)
 			__func__, vqid, err);
 }
 
+static int imx_rproc_attach(struct rproc *rproc)
+{
+	return 0;
+}
+
 static const struct rproc_ops imx_rproc_ops = {
 	.start		= imx_rproc_start,
 	.stop		= imx_rproc_stop,
+	.attach		= imx_rproc_attach,
 	.kick		= imx_rproc_kick,
 	.da_to_va       = imx_rproc_da_to_va,
 	.load		= rproc_elf_load_segments,
@@ -470,6 +491,8 @@ static int imx_rproc_addr_init(struct imx_rproc *priv,
 		}
 		priv->mem[b].sys_addr = res.start;
 		priv->mem[b].size = resource_size(&res);
+		if (!strcmp(node->name, "rsc_table"))
+			priv->rsc_table = priv->mem[b].cpu_addr;
 		b++;
 	}
 
@@ -536,6 +559,43 @@ static void imx_rproc_free_mbox(struct rproc *rproc)
 	mbox_free_channel(priv->rx_ch);
 }
 
+static int imx_rproc_detect_mode(struct imx_rproc *priv)
+{
+	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
+	struct rproc *rproc = priv->rproc;
+	struct device *dev = priv->dev;
+	int ret;
+	u32 val;
+
+	ret = regmap_read(priv->regmap, dcfg->src_reg, &val);
+	if (ret) {
+		dev_err(dev, "Failed to read src\n");
+		return ret;
+	}
+
+	if (!(val & dcfg->src_stop))
+		priv->mode = IMX_RPROC_EARLY_BOOT;
+	else
+		priv->mode = IMX_RPROC_NORMAL;
+
+	if (priv->mode == IMX_RPROC_EARLY_BOOT) {
+		priv->rproc->state = RPROC_DETACHED;
+
+		ret = imx_rproc_parse_memory_regions(priv->rproc);
+		if (ret)
+			return ret;
+
+		if (!priv->rsc_table)
+			return 0;
+
+		rproc->table_ptr = (struct resource_table *)priv->rsc_table;
+		rproc->table_sz = SZ_1K;
+		rproc->cached_table = NULL;
+	}
+
+	return 0;
+}
+
 static int imx_rproc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -590,6 +650,10 @@ static int imx_rproc_probe(struct platform_device *pdev)
 		goto err_put_mbox;
 	}
 
+	ret = imx_rproc_detect_mode(priv);
+	if (ret)
+		goto err_put_mbox;
+
 	priv->clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(priv->clk)) {
 		dev_err(dev, "Failed to get clock\n");
-- 
2.30.0