[PATCH v2 6/7] remoteproc: qcom_q6v5_pas: Add support to attach a DSP

[Melody Olvera <quic_molvera@quicinc.com>]

Some chipsets will have DSPs which will have begun running prior
to linux booting, so add support to late attach these DSPs by
adding support for:
- run-time checking of an offline or running DSP via rmb register
- a late attach framework to attach to the running DSP
- a handshake mechanism to ensure full and proper booting via rmb

Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>
---
 drivers/remoteproc/qcom_q6v5_pas.c | 103 ++++++++++++++++++++++++++++-
 1 file changed, 102 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
index 0871108fb4dc..e22be6a029a8 100644
--- a/drivers/remoteproc/qcom_q6v5_pas.c
+++ b/drivers/remoteproc/qcom_q6v5_pas.c
@@ -242,10 +242,89 @@ static int adsp_load(struct rproc *rproc, const struct firmware *fw)
 	return ret;
 }
 
+static int adsp_attach(struct rproc *rproc)
+{
+	struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
+	int i, ret;
+
+	ret = qcom_q6v5_prepare(&adsp->q6v5);
+	if (ret)
+		return ret;
+
+	ret = adsp_pds_enable(adsp, adsp->proxy_pds, adsp->proxy_pd_count);
+	if (ret < 0)
+		goto disable_irqs;
+
+	ret = clk_prepare_enable(adsp->xo);
+	if (ret)
+		goto disable_proxy_pds;
+
+	ret = clk_prepare_enable(adsp->aggre2_clk);
+	if (ret)
+		goto disable_xo_clk;
+
+	if (adsp->cx_supply) {
+		ret = regulator_enable(adsp->cx_supply);
+		if (ret)
+			goto disable_aggre2_clk;
+	}
+
+	if (adsp->px_supply) {
+		ret = regulator_enable(adsp->px_supply);
+		if (ret)
+			goto disable_cx_supply;
+	}
+
+	/* if needed, signal Q6 to continute booting */
+	if (adsp->q6v5.rmb_base) {
+		for (i = 0; i < RMB_POLL_MAX_TIMES; i++) {
+			if (readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
+				writel_relaxed(1, adsp->q6v5.rmb_base + RMB_BOOT_CONT_REG);
+				break;
+			}
+			msleep(20);
+		}
+
+		if (!readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
+			dev_err(adsp->dev, "Didn't get rmb signal from  %s\n", rproc->name);
+			goto disable_px_supply;
+		}
+	}
+
+	ret = qcom_q6v5_wait_for_start(&adsp->q6v5, msecs_to_jiffies(5000));
+	if (ret == -ETIMEDOUT) {
+		dev_err(adsp->dev, "start timed out\n");
+		qcom_scm_pas_shutdown(adsp->pas_id);
+		goto disable_px_supply;
+	}
+
+	return 0;
+
+disable_px_supply:
+	if (adsp->px_supply)
+		regulator_disable(adsp->px_supply);
+disable_cx_supply:
+	if (adsp->cx_supply)
+		regulator_disable(adsp->cx_supply);
+disable_aggre2_clk:
+	clk_disable_unprepare(adsp->aggre2_clk);
+disable_xo_clk:
+	clk_disable_unprepare(adsp->xo);
+disable_proxy_pds:
+	adsp_pds_disable(adsp, adsp->proxy_pds, adsp->proxy_pd_count);
+disable_irqs:
+	qcom_q6v5_unprepare(&adsp->q6v5);
+
+	/* Remove pointer to the loaded firmware, only valid in adsp_load() & adsp_start() */
+	adsp->firmware = NULL;
+
+	return ret;
+}
+
 static int adsp_start(struct rproc *rproc)
 {
 	struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
-	int ret;
+	int i, ret;
 
 	ret = qcom_q6v5_prepare(&adsp->q6v5);
 	if (ret)
@@ -304,6 +383,22 @@ static int adsp_start(struct rproc *rproc)
 		goto release_pas_metadata;
 	}
 
+	/* if needed, signal Q6 to continute booting */
+	if (adsp->q6v5.rmb_base) {
+		for (i = 0; i < RMB_POLL_MAX_TIMES; i++) {
+			if (readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
+				writel_relaxed(1, adsp->q6v5.rmb_base + RMB_BOOT_CONT_REG);
+				break;
+			}
+			msleep(20);
+		}
+
+		if (!readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
+			dev_err(adsp->dev, "Didn't get rmb signal from  %s\n", rproc->name);
+			goto release_pas_metadata;
+		}
+	}
+
 	ret = qcom_q6v5_wait_for_start(&adsp->q6v5, msecs_to_jiffies(5000));
 	if (ret == -ETIMEDOUT) {
 		dev_err(adsp->dev, "start timed out\n");
@@ -413,6 +508,7 @@ static unsigned long adsp_panic(struct rproc *rproc)
 static const struct rproc_ops adsp_ops = {
 	.unprepare = adsp_unprepare,
 	.start = adsp_start,
+	.attach = adsp_attach,
 	.stop = adsp_stop,
 	.da_to_va = adsp_da_to_va,
 	.parse_fw = qcom_register_dump_segments,
@@ -423,6 +519,7 @@ static const struct rproc_ops adsp_ops = {
 static const struct rproc_ops adsp_minidump_ops = {
 	.unprepare = adsp_unprepare,
 	.start = adsp_start,
+	.attach = adsp_attach,
 	.stop = adsp_stop,
 	.da_to_va = adsp_da_to_va,
 	.load = adsp_load,
@@ -728,6 +825,10 @@ static int adsp_probe(struct platform_device *pdev)
 	if (ret)
 		goto detach_proxy_pds;
 
+	if (adsp->q6v5.rmb_base &&
+			readl_relaxed(adsp->q6v5.rmb_base + RMB_Q6_BOOT_STATUS_REG))
+		rproc->state = RPROC_DETACHED;
+
 	qcom_add_glink_subdev(rproc, &adsp->glink_subdev, desc->ssr_name);
 	qcom_add_smd_subdev(rproc, &adsp->smd_subdev);
 	adsp->sysmon = qcom_add_sysmon_subdev(rproc,
-- 
2.25.1