[PATCH 1/2] i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming

[PATCH 1/2] i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming

[Jarkko Nikula]

MIPI I3C HCI on Intel hardware requires a quirk where ring needs to stop
and set to run again after resuming the halted controller. This is not
expected from the MIPI I3C HCI specification and is Intel specific.

Add this quirk to generic aborted transfer handling and execute it only
when ring is not in running state after a transfer error and attempted
controller resume. This is the case on Intel hardware.

It is not fully clear to me what is the ring running state in generic
hardware in such case. I would expect if ring is not running, then stop
request is a no-op and run request is either required or does the same
what controller resume would do.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
---
 drivers/i3c/master/mipi-i3c-hci/dma.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index e8e56a8d2057..491dfe70b660 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -758,9 +758,26 @@ static bool hci_dma_irq_handler(struct i3c_hci *hci)
 			complete(&rh->op_done);
 
 		if (status & INTR_TRANSFER_ABORT) {
+			u32 ring_status;
+
 			dev_notice_ratelimited(&hci->master.dev,
 				"ring %d: Transfer Aborted\n", i);
 			mipi_i3c_hci_resume(hci);
+			ring_status = rh_reg_read(RING_STATUS);
+			if (!(ring_status & RING_STATUS_RUNNING) &&
+			    status & INTR_TRANSFER_COMPLETION &&
+			    status & INTR_TRANSFER_ERR) {
+				/*
+				 * Ring stop followed by run is an Intel
+				 * specific required quirk after resuming the
+				 * halted controller. Do it only when the ring
+				 * is not in running state after a transfer
+				 * error.
+				 */
+				rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE);
+				rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE |
+							   RING_CTRL_RUN_STOP);
+			}
 		}
 		if (status & INTR_WARN_INS_STOP_MODE)
 			dev_warn_ratelimited(&hci->master.dev,
-- 
2.45.2


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[PATCH 2/2] i3c: mipi-i3c-hci: Add support for MIPI I3C HCI on PCI bus

[Jarkko Nikula]

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>
---
 drivers/i3c/master/Kconfig                    |  11 ++
 drivers/i3c/master/mipi-i3c-hci/Makefile      |   1 +
 .../master/mipi-i3c-hci/mipi-i3c-hci-pci.c    | 148 ++++++++++++++++++
 3 files changed, 160 insertions(+)
 create mode 100644 drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c

diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig
index 90dee3ec5520..77da199c7413 100644
--- a/drivers/i3c/master/Kconfig
+++ b/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.
diff --git a/drivers/i3c/master/mipi-i3c-hci/Makefile b/drivers/i3c/master/mipi-i3c-hci/Makefile
index 1f8cd5c48fde..e3d3ef757035 100644
--- a/drivers/i3c/master/mipi-i3c-hci/Makefile
+++ b/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
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
new file mode 100644
index 000000000000..c6c3a3ec11ea
--- /dev/null
+++ b/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");
-- 
2.45.2


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Re: [PATCH 1/2] i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming

[Alexandre Belloni]

On Tue, 31 Dec 2024 13:59:03 +0200, Jarkko Nikula wrote:
> MIPI I3C HCI on Intel hardware requires a quirk where ring needs to stop
> and set to run again after resuming the halted controller. This is not
> expected from the MIPI I3C HCI specification and is Intel specific.
> 
> Add this quirk to generic aborted transfer handling and execute it only
> when ring is not in running state after a transfer error and attempted
> controller resume. This is the case on Intel hardware.
> 
> [...]

Applied, thanks!

[1/2] i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming
      https://git.kernel.org/abelloni/c/ccdb2e0e3b00
[2/2] i3c: mipi-i3c-hci: Add support for MIPI I3C HCI on PCI bus
      https://git.kernel.org/abelloni/c/30bb1ce71215

Best regards,

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Embedded Linux and Kernel engineering
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