[PATCH V2 09/10] i3c: mipi-i3c-hci-pci: Add support for Multi-Bus Instances

[Adrian Hunter]

A MIPI I3C Host Controller with the Multi-Bus Instance capability supports
multiple I3C Buses (up to 15), with one instance of the HCI Register Set
and one instance of I3C Bus Controller Logic for each I3C Bus, in a single
hardware function (e.g. PCIe B/D/F).

Create an MFD cell for each instance.  Use platform_data to pass the
instance's register set start address.

MIPI I3C specification defines an Extended Capability to hold the offset
of each instance register set.  However parsing to find that information is
relatively complicated compared with just including it in the driver data.
Do that for now.

Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
---


Changes in V2:
	Conversion to MFD split into separate patch
	Simplify ID allocation / free
	Correct use of __free()
	Also define instance 0 in driver_data


 .../master/mipi-i3c-hci/mipi-i3c-hci-pci.c    | 63 +++++++++++++++----
 1 file changed, 50 insertions(+), 13 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
index 68088967942b..de1f71763786 100644
--- a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
+++ b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
@@ -19,10 +19,17 @@
 #include <linux/platform_device.h>
 #include <linux/pm_qos.h>
 
+/*
+ * There can up to 15 instances, but implementations have at most 2 at this
+ * time.
+ */
+#define INST_MAX 2
+
 struct mipi_i3c_hci_pci {
 	struct pci_dev *pci;
 	void __iomem *base;
-	int dev_id;
+	int dev_id[INST_MAX];
+	int dev_id_cnt;
 	const struct mipi_i3c_hci_pci_info *info;
 	void *private;
 };
@@ -30,6 +37,8 @@ struct mipi_i3c_hci_pci {
 struct mipi_i3c_hci_pci_info {
 	int (*init)(struct mipi_i3c_hci_pci *hci);
 	void (*exit)(struct mipi_i3c_hci_pci *hci);
+	u32 instance_offset[INST_MAX];
+	int instance_count;
 };
 
 static DEFINE_IDA(mipi_i3c_hci_pci_ida);
@@ -177,53 +186,81 @@ static void intel_i3c_exit(struct mipi_i3c_hci_pci *hci)
 static const struct mipi_i3c_hci_pci_info intel_info = {
 	.init = intel_i3c_init,
 	.exit = intel_i3c_exit,
+	.instance_offset = {0},
+	.instance_count = 1,
 };
 
+static void mipi_i3c_hci_pci_free_ids(struct mipi_i3c_hci_pci *hci)
+{
+	for (int i = 0; i < hci->dev_id_cnt; i++)
+		ida_free(&mipi_i3c_hci_pci_ida, hci->dev_id[i]);
+}
+
+static int mipi_i3c_hci_pci_alloc_ids(struct mipi_i3c_hci_pci *hci, int nr)
+{
+	for (int i = 0; i < nr; i++) {
+		hci->dev_id[i] = ida_alloc(&mipi_i3c_hci_pci_ida, GFP_KERNEL);
+		if (hci->dev_id[i]  < 0)
+			goto err_free_ids;
+		hci->dev_id_cnt = i + 1;
+	}
+
+	return 0;
+
+err_free_ids:
+	mipi_i3c_hci_pci_free_ids(hci);
+	return -ENOMEM;
+}
+
 struct mipi_i3c_hci_pci_cell_data {
 	struct mipi_i3c_hci_platform_data pdata;
 	struct resource res;
 };
 
-static void mipi_i3c_hci_pci_setup_cell(struct mipi_i3c_hci_pci *hci,
+static void mipi_i3c_hci_pci_setup_cell(struct mipi_i3c_hci_pci *hci, int idx,
 					struct mipi_i3c_hci_pci_cell_data *data,
 					struct mfd_cell *cell)
 {
-	data->pdata.base_regs = hci->base;
+	data->pdata.base_regs = hci->base + hci->info->instance_offset[idx];
 
 	data->res = DEFINE_RES_IRQ(0);
 
 	cell->name = "mipi-i3c-hci";
-	cell->id = hci->dev_id;
+	cell->id = hci->dev_id[idx];
 	cell->platform_data = &data->pdata;
 	cell->pdata_size = sizeof(data->pdata);
 	cell->num_resources = 1;
 	cell->resources = &data->res;
 }
 
+#define mipi_i3c_hci_pci_alloc(x) kcalloc(hci->info->instance_count, sizeof(*(x)), GFP_KERNEL)
+
 static int mipi_i3c_hci_pci_add_instances(struct mipi_i3c_hci_pci *hci)
 {
-	struct mipi_i3c_hci_pci_cell_data *data __free(kfree) = kzalloc(sizeof(*data), GFP_KERNEL);
-	struct mfd_cell *cells __free(kfree) = kzalloc(sizeof(*cells), GFP_KERNEL);
+	struct mipi_i3c_hci_pci_cell_data *data __free(kfree) = mipi_i3c_hci_pci_alloc(data);
+	struct mfd_cell *cells __free(kfree) = mipi_i3c_hci_pci_alloc(cells);
 	int irq = pci_irq_vector(hci->pci, 0);
+	int nr = hci->info->instance_count;
 	int ret;
 
 	if (!cells || !data)
 		return -ENOMEM;
 
-	hci->dev_id = ida_alloc(&mipi_i3c_hci_pci_ida, GFP_KERNEL);
-	if (hci->dev_id < 0)
-		return hci->dev_id;
+	ret = mipi_i3c_hci_pci_alloc_ids(hci, nr);
+	if (ret)
+		return ret;
 
-	mipi_i3c_hci_pci_setup_cell(hci, data, cells);
+	for (int i = 0; i < nr; i++)
+		mipi_i3c_hci_pci_setup_cell(hci, i, data + i, cells + i);
 
-	ret = mfd_add_devices(&hci->pci->dev, 0, cells, 1, NULL, irq, NULL);
+	ret = mfd_add_devices(&hci->pci->dev, 0, cells, nr, NULL, irq, NULL);
 	if (ret)
 		goto err_free_ids;
 
 	return 0;
 
 err_free_ids:
-	ida_free(&mipi_i3c_hci_pci_ida, hci->dev_id);
+	mipi_i3c_hci_pci_free_ids(hci);
 	return ret;
 }
 
@@ -281,7 +318,7 @@ static void mipi_i3c_hci_pci_remove(struct pci_dev *pci)
 		hci->info->exit(hci);
 
 	mfd_remove_devices(&pci->dev);
-	ida_free(&mipi_i3c_hci_pci_ida, hci->dev_id);
+	mipi_i3c_hci_pci_free_ids(hci);
 }
 
 static const struct pci_device_id mipi_i3c_hci_pci_devices[] = {
-- 
2.51.0