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

[Peng Fan (OSS)]

From: Peng Fan <peng....@nxp.com>

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....@nxp.com>
---
 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