[PATCH 2/2] mailbox: qcom-cpucp: Add support for Nord CPUCP mailbox controller

[Shawn Guo <shengchao.guo@oss.qualcomm.com>]

From: Deepti Jaggi <deepti.jaggi@oss.qualcomm.com>

The Nord SoC CPUCP mailbox supports 16 IPC channels, compared to 3 on
x1e80100. The existing driver hardcodes the channel count via a
compile-time constant (APSS_CPUCP_IPC_CHAN_SUPPORTED), making it
impossible to support hardware with a different number of channels.

Introduce a qcom_cpucp_mbox_data per-hardware configuration struct that
carries the channel count, and retrieve it via of_device_get_match_data()
at probe time. Switch the channel array from a fixed-size member to a
dynamically allocated buffer sized from the hardware data. Update the
x1e80100 entry to supply its own data struct, and add a new Nord entry
with num_chans = 16.

Signed-off-by: Deepti Jaggi <deepti.jaggi@oss.qualcomm.com>
Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
---
 drivers/mailbox/qcom-cpucp-mbox.c | 37 ++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/drivers/mailbox/qcom-cpucp-mbox.c b/drivers/mailbox/qcom-cpucp-mbox.c
index 44f4ed15f818..624a4e9eb6c6 100644
--- a/drivers/mailbox/qcom-cpucp-mbox.c
+++ b/drivers/mailbox/qcom-cpucp-mbox.c
@@ -12,7 +12,6 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 
-#define APSS_CPUCP_IPC_CHAN_SUPPORTED		3
 #define APSS_CPUCP_MBOX_CMD_OFF			0x4
 
 /* Tx Registers */
@@ -26,15 +25,23 @@
 #define APSS_CPUCP_RX_MBOX_EN			0x4c00
 #define APSS_CPUCP_RX_MBOX_CMD_MASK		GENMASK_ULL(63, 0)
 
+/**
+ * struct qcom_cpucp_mbox_data - Per-hardware mailbox configuration data
+ * @num_chans:			Number of IPC channels supported by this hardware
+ */
+struct qcom_cpucp_mbox_data {
+	int num_chans;
+};
+
 /**
  * struct qcom_cpucp_mbox - Holder for the mailbox driver
- * @chans:			The mailbox channel
+ * @chans:			The mailbox channels (dynamically allocated)
  * @mbox:			The mailbox controller
  * @tx_base:			Base address of the CPUCP tx registers
  * @rx_base:			Base address of the CPUCP rx registers
  */
 struct qcom_cpucp_mbox {
-	struct mbox_chan chans[APSS_CPUCP_IPC_CHAN_SUPPORTED];
+	struct mbox_chan *chans;
 	struct mbox_controller mbox;
 	void __iomem *tx_base;
 	void __iomem *rx_base;
@@ -53,7 +60,7 @@ static irqreturn_t qcom_cpucp_mbox_irq_fn(int irq, void *data)
 
 	status = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_STAT);
 
-	for_each_set_bit(i, (unsigned long *)&status, APSS_CPUCP_IPC_CHAN_SUPPORTED) {
+	for_each_set_bit(i, (unsigned long *)&status, cpucp->mbox.num_chans) {
 		u32 val = readl(cpucp->rx_base + APSS_CPUCP_RX_MBOX_CMD(i) + APSS_CPUCP_MBOX_CMD_OFF);
 		struct mbox_chan *chan = &cpucp->chans[i];
 		unsigned long flags;
@@ -112,15 +119,24 @@ static const struct mbox_chan_ops qcom_cpucp_mbox_chan_ops = {
 
 static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
 {
+	const struct qcom_cpucp_mbox_data *data;
 	struct device *dev = &pdev->dev;
 	struct qcom_cpucp_mbox *cpucp;
 	struct mbox_controller *mbox;
 	int irq, ret;
 
+	data = of_device_get_match_data(dev);
+	if (!data)
+		return dev_err_probe(dev, -EINVAL, "No match data found\n");
+
 	cpucp = devm_kzalloc(dev, sizeof(*cpucp), GFP_KERNEL);
 	if (!cpucp)
 		return -ENOMEM;
 
+	cpucp->chans = devm_kcalloc(dev, data->num_chans, sizeof(*cpucp->chans), GFP_KERNEL);
+	if (!cpucp->chans)
+		return -ENOMEM;
+
 	cpucp->rx_base = devm_of_iomap(dev, dev->of_node, 0, NULL);
 	if (IS_ERR(cpucp->rx_base))
 		return PTR_ERR(cpucp->rx_base);
@@ -146,7 +162,7 @@ static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
 
 	mbox = &cpucp->mbox;
 	mbox->dev = dev;
-	mbox->num_chans = APSS_CPUCP_IPC_CHAN_SUPPORTED;
+	mbox->num_chans = data->num_chans;
 	mbox->chans = cpucp->chans;
 	mbox->ops = &qcom_cpucp_mbox_chan_ops;
 
@@ -157,8 +173,17 @@ static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct qcom_cpucp_mbox_data qcom_x1e80100_mbox_data = {
+	.num_chans = 3,
+};
+
+static const struct qcom_cpucp_mbox_data qcom_nord_mbox_data = {
+	.num_chans = 16,
+};
+
 static const struct of_device_id qcom_cpucp_mbox_of_match[] = {
-	{ .compatible = "qcom,x1e80100-cpucp-mbox" },
+	{ .compatible = "qcom,nord-cpucp-mbox", .data = &qcom_nord_mbox_data },
+	{ .compatible = "qcom,x1e80100-cpucp-mbox", .data = &qcom_x1e80100_mbox_data },
 	{}
 };
 MODULE_DEVICE_TABLE(of, qcom_cpucp_mbox_of_match);
-- 
2.43.0