i3c: mipi-i3c-hci: Add support for MIPI I3C HCI on PCI bus

Add a glue code for the MIPI I3C HCI on PCI bus with Intel Panther Lake
I3C controller PCI IDs.

MIPI I3C HCI on Intel platforms has additional logic around the MIPI I3C
HCI core logic. Those together create so called I3C slice on PCI bus.
Intel specific initialization code does a reset cycle to the I3C slice
before probing the MIPI I3C HCI part.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20241231115904.620052-2-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/i3c/master/Kconfig

@@ -57,3 +57,14 @@ config MIPI_I3C_HCI
 
 	  This driver can also be built as a module.  If so, the module will be
 	  called mipi-i3c-hci.
+
+config MIPI_I3C_HCI_PCI
+	tristate "MIPI I3C Host Controller Interface PCI support"
+	depends on MIPI_I3C_HCI
+	depends on PCI
+	help
+	  Support for MIPI I3C Host Controller Interface compatible hardware
+	  on the PCI bus.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called mipi-i3c-hci-pci.

drivers/i3c/master/mipi-i3c-hci/Makefile

@@ -5,3 +5,4 @@ mipi-i3c-hci-y				:= core.o ext_caps.o pio.o dma.o \
 					   cmd_v1.o cmd_v2.o \
 					   dat_v1.o dct_v1.o \
 					   hci_quirks.o
+obj-$(CONFIG_MIPI_I3C_HCI_PCI)		+= mipi-i3c-hci-pci.o

drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c

@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI glue code for MIPI I3C HCI driver
+ *
+ * Copyright (C) 2024 Intel Corporation
+ *
+ * Author: Jarkko Nikula <jarkko.nikula@linux.intel.com>
+ */
+#include <linux/acpi.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+struct mipi_i3c_hci_pci_info {
+	int (*init)(struct pci_dev *pci);
+};
+
+#define INTEL_PRIV_OFFSET		0x2b0
+#define INTEL_PRIV_SIZE			0x28
+#define INTEL_PRIV_RESETS		0x04
+#define INTEL_PRIV_RESETS_RESET		BIT(0)
+#define INTEL_PRIV_RESETS_RESET_DONE	BIT(1)
+
+static DEFINE_IDA(mipi_i3c_hci_pci_ida);
+
+static int mipi_i3c_hci_pci_intel_init(struct pci_dev *pci)
+{
+	unsigned long timeout;
+	void __iomem *priv;
+
+	priv = devm_ioremap(&pci->dev,
+			    pci_resource_start(pci, 0) + INTEL_PRIV_OFFSET,
+			    INTEL_PRIV_SIZE);
+	if (!priv)
+		return -ENOMEM;
+
+	/* Assert reset, wait for completion and release reset */
+	writel(0, priv + INTEL_PRIV_RESETS);
+	timeout = jiffies + msecs_to_jiffies(10);
+	while (!(readl(priv + INTEL_PRIV_RESETS) &
+		 INTEL_PRIV_RESETS_RESET_DONE)) {
+		if (time_after(jiffies, timeout))
+			break;
+		cpu_relax();
+	}
+	writel(INTEL_PRIV_RESETS_RESET, priv + INTEL_PRIV_RESETS);
+
+	return 0;
+}
+
+static struct mipi_i3c_hci_pci_info intel_info = {
+	.init = mipi_i3c_hci_pci_intel_init,
+};
+
+static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
+				  const struct pci_device_id *id)
+{
+	struct mipi_i3c_hci_pci_info *info;
+	struct platform_device *pdev;
+	struct resource res[2];
+	int dev_id, ret;
+
+	ret = pcim_enable_device(pci);
+	if (ret)
+		return ret;
+
+	pci_set_master(pci);
+
+	memset(&res, 0, sizeof(res));
+
+	res[0].flags = IORESOURCE_MEM;
+	res[0].start = pci_resource_start(pci, 0);
+	res[0].end = pci_resource_end(pci, 0);
+
+	res[1].flags = IORESOURCE_IRQ;
+	res[1].start = pci->irq;
+	res[1].end = pci->irq;
+
+	dev_id = ida_alloc(&mipi_i3c_hci_pci_ida, GFP_KERNEL);
+	if (dev_id < 0)
+		return dev_id;
+
+	pdev = platform_device_alloc("mipi-i3c-hci", dev_id);
+	if (!pdev)
+		return -ENOMEM;
+
+	pdev->dev.parent = &pci->dev;
+	device_set_node(&pdev->dev, dev_fwnode(&pci->dev));
+
+	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
+	if (ret)
+		goto err;
+
+	info = (struct mipi_i3c_hci_pci_info *)id->driver_data;
+	if (info && info->init) {
+		ret = info->init(pci);
+		if (ret)
+			goto err;
+	}
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto err;
+
+	pci_set_drvdata(pci, pdev);
+
+	return 0;
+
+err:
+	platform_device_put(pdev);
+	ida_free(&mipi_i3c_hci_pci_ida, dev_id);
+	return ret;
+}
+
+static void mipi_i3c_hci_pci_remove(struct pci_dev *pci)
+{
+	struct platform_device *pdev = pci_get_drvdata(pci);
+	int dev_id = pdev->id;
+
+	platform_device_unregister(pdev);
+	ida_free(&mipi_i3c_hci_pci_ida, dev_id);
+}
+
+static const struct pci_device_id mipi_i3c_hci_pci_devices[] = {
+	/* Panther Lake-H */
+	{ PCI_VDEVICE(INTEL, 0xe37c), (kernel_ulong_t)&intel_info},
+	{ PCI_VDEVICE(INTEL, 0xe36f), (kernel_ulong_t)&intel_info},
+	/* Panther Lake-P */
+	{ PCI_VDEVICE(INTEL, 0xe47c), (kernel_ulong_t)&intel_info},
+	{ PCI_VDEVICE(INTEL, 0xe46f), (kernel_ulong_t)&intel_info},
+	{ },
+};
+MODULE_DEVICE_TABLE(pci, mipi_i3c_hci_pci_devices);
+
+static struct pci_driver mipi_i3c_hci_pci_driver = {
+	.name = "mipi_i3c_hci_pci",
+	.id_table = mipi_i3c_hci_pci_devices,
+	.probe = mipi_i3c_hci_pci_probe,
+	.remove = mipi_i3c_hci_pci_remove,
+};
+
+module_pci_driver(mipi_i3c_hci_pci_driver);
+
+MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MIPI I3C HCI driver on PCI bus");