Re: [PATCH 5/9] remoteproc: mss: q6v5-mss: Add modem support on SC7280

Add out of reset sequence support for modem sub-system on SC7280 SoCs.
It requires access to an additional set of qaccept registers, external
power/clk control registers and halt vq6 register to put the modem back
into reset.

Signed-off-by: Sibi Sankar <redacted>
---
 drivers/remoteproc/qcom_q6v5_mss.c | 245 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 241 insertions(+), 4 deletions(-)

diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
index 5d21084004cb..4e32811e0025 100644
--- a/drivers/remoteproc/qcom_q6v5_mss.c
+++ b/drivers/remoteproc/qcom_q6v5_mss.c

@@ -77,6 +77,14 @@
 
 #define HALT_ACK_TIMEOUT_US		100000
 
+/* QACCEPT Register Offsets */
+#define QACCEPT_ACCEPT_REG		0x0
+#define QACCEPT_ACTIVE_REG		0x4
+#define QACCEPT_DENY_REG		0x8
+#define QACCEPT_REQ_REG			0xC
+
+#define QACCEPT_TIMEOUT_US		50
+
 /* QDSP6SS_RESET */
 #define Q6SS_STOP_CORE			BIT(0)
 #define Q6SS_CORE_ARES			BIT(1)

@@ -143,6 +151,9 @@ struct rproc_hexagon_res {
 	bool has_alt_reset;
 	bool has_mba_logs;
 	bool has_spare_reg;
+	bool has_qaccept_regs;
+	bool has_ext_cntl_regs;
+	bool has_vq6;
 };
 
 struct q6v5 {

@@ -158,8 +169,18 @@ struct q6v5 {
 	u32 halt_q6;
 	u32 halt_modem;
 	u32 halt_nc;
+	u32 halt_vq6;
 	u32 conn_box;
 
+	u32 qaccept_mdm;
+	u32 qaccept_cx;
+	u32 qaccept_axi;
+
+	u32 axim1_clk_off;
+	u32 crypto_clk_off;
+	u32 force_clk_on;
+	u32 rscc_disable;
+
 	struct reset_control *mss_restart;
 	struct reset_control *pdc_reset;
 

@@ -201,6 +222,9 @@ struct q6v5 {
 	bool has_alt_reset;
 	bool has_mba_logs;
 	bool has_spare_reg;
+	bool has_qaccept_regs;
+	bool has_ext_cntl_regs;
+	bool has_vq6;
 	int mpss_perm;
 	int mba_perm;
 	const char *hexagon_mdt_image;

@@ -213,6 +237,7 @@ enum {
 	MSS_MSM8996,
 	MSS_MSM8998,
 	MSS_SC7180,
+	MSS_SC7280,
 	MSS_SDM845,
 };
 

@@ -473,6 +498,12 @@ static int q6v5_reset_assert(struct q6v5 *qproc)
 		regmap_update_bits(qproc->conn_map, qproc->conn_box,
 				   AXI_GATING_VALID_OVERRIDE, 0);
 		ret = reset_control_deassert(qproc->mss_restart);
+	} else if (qproc->has_ext_cntl_regs) {
+		regmap_write(qproc->conn_map, qproc->rscc_disable, 0);
+		reset_control_assert(qproc->pdc_reset);
+		reset_control_assert(qproc->mss_restart);
+		reset_control_deassert(qproc->pdc_reset);
+		ret = reset_control_deassert(qproc->mss_restart);
 	} else {
 		ret = reset_control_assert(qproc->mss_restart);
 	}

@@ -490,7 +521,7 @@ static int q6v5_reset_deassert(struct q6v5 *qproc)
 		ret = reset_control_reset(qproc->mss_restart);
 		writel(0, qproc->rmb_base + RMB_MBA_ALT_RESET);
 		reset_control_deassert(qproc->pdc_reset);
-	} else if (qproc->has_spare_reg) {
+	} else if (qproc->has_spare_reg || qproc->has_ext_cntl_regs) {
 		ret = reset_control_reset(qproc->mss_restart);
 	} else {
 		ret = reset_control_deassert(qproc->mss_restart);

@@ -604,7 +635,7 @@ static int q6v5proc_reset(struct q6v5 *qproc)
 		}
 
 		goto pbl_wait;
-	} else if (qproc->version == MSS_SC7180) {
+	} else if (qproc->version == MSS_SC7180 || qproc->version == MSS_SC7280) {
 		val = readl(qproc->reg_base + QDSP6SS_SLEEP);
 		val |= Q6SS_CBCR_CLKEN;
 		writel(val, qproc->reg_base + QDSP6SS_SLEEP);

@@ -787,6 +818,82 @@ static int q6v5proc_reset(struct q6v5 *qproc)
 	return ret;
 }
 
+static int q6v5proc_enable_qchannel(struct q6v5 *qproc, struct regmap *map, u32 offset)
+{
+	unsigned int val;
+	int ret;
+
+	if (!qproc->has_qaccept_regs)
+		return 0;
+
+	if (qproc->has_ext_cntl_regs) {
+		regmap_write(qproc->conn_map, qproc->rscc_disable, 0);
+		regmap_write(qproc->conn_map, qproc->force_clk_on, 1);
+
+		ret = regmap_read_poll_timeout(qproc->halt_map, qproc->axim1_clk_off, val,
+					       !val, 1, Q6SS_CBCR_TIMEOUT_US);
+		if (ret) {
+			dev_err(qproc->dev, "failed to enable axim1 clock\n");
+			return -ETIMEDOUT;
+		}
+	}
+
+	regmap_write(map, offset + QACCEPT_REQ_REG, 1);
+
+	/* Wait for accept */
+	ret = regmap_read_poll_timeout(map, offset + QACCEPT_ACCEPT_REG, val, val, 5,
+				       QACCEPT_TIMEOUT_US);
+	if (ret) {
+		dev_err(qproc->dev, "qchannel enable failed\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void q6v5proc_disable_qchannel(struct q6v5 *qproc, struct regmap *map, u32 offset)
+{
+	int ret;
+	unsigned int val, retry;
+	unsigned int nretry = 10;
+	bool takedown_complete = false;
+
+	if (!qproc->has_qaccept_regs)
+		return;
+
+	while (!takedown_complete && nretry) {
+		nretry--;
+
+		regmap_read_poll_timeout(map, offset + QACCEPT_ACTIVE_REG, val, !val, 5,
+					 QACCEPT_TIMEOUT_US);
+
+		regmap_write(map, offset + QACCEPT_REQ_REG, 0);
+
+		retry = 10;
+		while (retry) {
+			usleep_range(5, 10);
+			retry--;
+			ret = regmap_read(map, offset + QACCEPT_DENY_REG, &val);
+			if (!ret && val) {
+				regmap_write(map, offset + QACCEPT_REQ_REG, 1);
+				break;
+			}
+
+			ret = regmap_read(map, offset + QACCEPT_ACCEPT_REG, &val);
+			if (!ret && !val) {
+				takedown_complete = true;
+				break;
+			}

+		}
+
+		if (!retry)
+			break;
+	}
+
+	if (!takedown_complete)
+		dev_err(qproc->dev, "qchannel takedown failed\n");
+}