remoteproc: imx_rproc: support i.MX7ULP

i.MX7ULP A7 core runs under control of M4 core, M4 core starts by ROM
and powers most services used by A7 core, so A7 core has no power to
start and stop M4 core. And the M4 core's state is default RPROC_DETACHED
and remoteproc framework not able to stop the M4 core.

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1620274123-1461-8-git-send-email-peng.fan@oss.nxp.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/imx_rproc.c

@@ -136,6 +136,14 @@ static const struct imx_rproc_att imx_rproc_att_imx8mq[] = {
 	{ 0x40000000, 0x40000000, 0x80000000, 0 },
 };
 
+static const struct imx_rproc_att imx_rproc_att_imx7ulp[] = {
+	{0x1FFD0000, 0x1FFD0000, 0x30000, ATT_OWN},
+	{0x20000000, 0x20000000, 0x10000, ATT_OWN},
+	{0x2F000000, 0x2F000000, 0x20000, ATT_OWN},
+	{0x2F020000, 0x2F020000, 0x20000, ATT_OWN},
+	{0x60000000, 0x60000000, 0x40000000, 0}
+};
+
 static const struct imx_rproc_att imx_rproc_att_imx7d[] = {
 	/* dev addr , sys addr  , size	    , flags */
 	/* OCRAM_S (M4 Boot code) - alias */
@@ -196,6 +204,12 @@ static const struct imx_rproc_dcfg imx_rproc_cfg_imx8mq = {
 	.method		= IMX_RPROC_MMIO,
 };
 
+static const struct imx_rproc_dcfg imx_rproc_cfg_imx7ulp = {
+	.att		= imx_rproc_att_imx7ulp,
+	.att_size	= ARRAY_SIZE(imx_rproc_att_imx7ulp),
+	.method		= IMX_RPROC_NONE,
+};
+
 static const struct imx_rproc_dcfg imx_rproc_cfg_imx7d = {
 	.src_reg	= IMX7D_SRC_SCR,
 	.src_mask	= IMX7D_M4_RST_MASK,
@@ -238,6 +252,9 @@ static int imx_rproc_stop(struct rproc *rproc)
 	struct device *dev = priv->dev;
 	int ret;
 
+	if (dcfg->method == IMX_RPROC_NONE)
+		return -EOPNOTSUPP;
+
 	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
 				 dcfg->src_mask, dcfg->src_stop);
 	if (ret)
@@ -573,12 +590,31 @@ static void imx_rproc_free_mbox(struct rproc *rproc)
 
 static int imx_rproc_detect_mode(struct imx_rproc *priv)
 {
+	struct regmap_config config = { .name = "imx-rproc" };
 	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
 	struct device *dev = priv->dev;
+	struct regmap *regmap;
 	int ret;
 	u32 val;
 
-	ret = regmap_read(priv->regmap, dcfg->src_reg, &val);
+	switch (dcfg->method) {
+	case IMX_RPROC_NONE:
+		priv->rproc->state = RPROC_DETACHED;
+		return 0;
+	default:
+		break;
+	}
+
+	regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "failed to find syscon\n");
+		return PTR_ERR(regmap);
+	}
+
+	priv->regmap = regmap;
+	regmap_attach_dev(dev, regmap, &config);
+
+	ret = regmap_read(regmap, dcfg->src_reg, &val);
 	if (ret) {
 		dev_err(dev, "Failed to read src\n");
 		return ret;
@@ -625,18 +661,9 @@ static int imx_rproc_probe(struct platform_device *pdev)
 	struct device_node *np = dev->of_node;
 	struct imx_rproc *priv;
 	struct rproc *rproc;
-	struct regmap_config config = { .name = "imx-rproc" };
 	const struct imx_rproc_dcfg *dcfg;
-	struct regmap *regmap;
 	int ret;
 
-	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
-	if (IS_ERR(regmap)) {
-		dev_err(dev, "failed to find syscon\n");
-		return PTR_ERR(regmap);
-	}
-	regmap_attach_dev(dev, regmap, &config);
-
 	/* set some other name then imx */
 	rproc = rproc_alloc(dev, "imx-rproc", &imx_rproc_ops,
 			    NULL, sizeof(*priv));
@@ -651,7 +678,6 @@ static int imx_rproc_probe(struct platform_device *pdev)
 
 	priv = rproc->priv;
 	priv->rproc = rproc;
-	priv->regmap = regmap;
 	priv->dcfg = dcfg;
 	priv->dev = dev;
 
@@ -720,6 +746,7 @@ static int imx_rproc_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id imx_rproc_of_match[] = {
+	{ .compatible = "fsl,imx7ulp-cm4", .data = &imx_rproc_cfg_imx7ulp },
 	{ .compatible = "fsl,imx7d-cm4", .data = &imx_rproc_cfg_imx7d },
 	{ .compatible = "fsl,imx6sx-cm4", .data = &imx_rproc_cfg_imx6sx },
 	{ .compatible = "fsl,imx8mq-cm4", .data = &imx_rproc_cfg_imx8mq },