[PATCH v2 05/12] remoteproc: stm32: Parse syscon that will manage M4 synchronisation

[Mathieu Poirier <mathieu.poirier@linaro.org>]

Get from the DT the syncon to probe the state of the remote processor
and the location of the resource table.

Mainly based on the work published by Arnaud Pouliquen [1].

[1]. https://patchwork.kernel.org/project/linux-remoteproc/list/?series=239877

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Loic Pallardy <loic.pallardy@st.com>
---
 drivers/remoteproc/stm32_rproc.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
index 658439d4b00a..a285f338bed8 100644
--- a/drivers/remoteproc/stm32_rproc.c
+++ b/drivers/remoteproc/stm32_rproc.c
@@ -70,6 +70,8 @@ struct stm32_rproc {
 	struct reset_control *rst;
 	struct stm32_syscon hold_boot;
 	struct stm32_syscon pdds;
+	struct stm32_syscon m4_state;
+	struct stm32_syscon rsctbl;
 	int wdg_irq;
 	u32 nb_rmems;
 	struct stm32_rproc_mem *rmems;
@@ -606,6 +608,30 @@ static int stm32_rproc_parse_dt(struct platform_device *pdev,
 
 	*auto_boot = of_property_read_bool(np, "st,auto-boot");
 
+	/*
+	 * See if we can check the M4 status, i.e if it was started
+	 * from the boot loader or not.
+	 */
+	err = stm32_rproc_get_syscon(np, "st,syscfg-m4-state",
+				     &ddata->m4_state);
+	if (err) {
+		/* remember this */
+		ddata->m4_state.map = NULL;
+		/* no coprocessor state syscon (optional) */
+		dev_warn(dev, "m4 state not supported\n");
+
+		/* no need to go further */
+		return 0;
+	}
+
+	/* See if we can get the resource table */
+	err = stm32_rproc_get_syscon(np, "st,syscfg-rsc-tbl",
+				     &ddata->rsctbl);
+	if (err) {
+		/* no rsc table syscon (optional) */
+		dev_warn(dev, "rsc tbl syscon not supported\n");
+	}
+
 	return 0;
 }
 
-- 
2.20.1