[PATCH v3 0/5] Introduce initial AMD I3C HCI driver support

[PATCH v3 0/5] Introduce initial AMD I3C HCI driver support

[Shyam Sundar S K]

The AMD SoC includes an I3C IP block as part of the Fusion Controller Hub
(FCH). This series introduces the initial driver support to enable the I3C
IP block on AMD's latest processors.

Currently, the code is closely tied to dt-bindings. This initial set aims
to decouple some of these bindings by adding the MIPI ID, allowing the
current driver to support ACPI-enabled x86 systems.

It was discovered that the AMD I3C controller has several hardware issues,
including:
- Non-functional DMA mode (defaulting to PIO mode)
- Issues with Open-Drain (OD) and Push-Pull (PP) timing parameters
- Command response buffer threshold values

All of these issues have been addressed in this series.

v2->v3:
-------
 - use MODULE_DEVICE_TABLE()
 - realign patches
 - address remarks from Jarkko
 
v1->v2:
-------
 - Address LKP reported problems
 - Guard boot_cpu_data usage with CONFIG_X86

Shyam Sundar S K (5):
  i3c: mipi-i3c-hci: Add MIPI0100 ACPI ID to the I3C Support List
  i3c: mipi-i3c-hci: Add a quirk to set PIO mode
  i3c: mipi-i3c-hci: Relocate helper macros to HCI header file
  i3c: mipi-i3c-hci: Add a quirk to set timing parameters
  i3c: mipi-i3c-hci: Add a quirk to set Response buffer threshold

 drivers/i3c/master/mipi-i3c-hci/Makefile     |  3 +-
 drivers/i3c/master/mipi-i3c-hci/core.c       | 36 ++++++++++---
 drivers/i3c/master/mipi-i3c-hci/hci.h        | 12 +++++
 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c | 55 ++++++++++++++++++++
 4 files changed, 98 insertions(+), 8 deletions(-)
 create mode 100644 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c

-- 
2.25.1

[PATCH v3 1/5] i3c: mipi-i3c-hci: Add MIPI0100 ACPI ID to the I3C Support List

[Shyam Sundar S K]

The current driver code lacks the necessary plumbing for ACPI IDs,
preventing the mipi-i3c-hci driver from being loaded on x86
platforms that advertise I3C ACPI support.

This update adds the MIPI0100 ACPI ID to the list of supported IDs.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index 4e7d6a43ee9b..5ef848833a81 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -834,12 +834,19 @@ static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
 
+static const struct acpi_device_id i3c_hci_acpi_match[] = {
+	{"MIPI0100"},
+	{}
+};
+MODULE_DEVICE_TABLE(platform, i3c_hci_acpi_match);
+
 static struct platform_driver i3c_hci_driver = {
 	.probe = i3c_hci_probe,
 	.remove_new = i3c_hci_remove,
 	.driver = {
 		.name = "mipi-i3c-hci",
 		.of_match_table = of_match_ptr(i3c_hci_of_match),
+		.acpi_match_table = i3c_hci_acpi_match,
 	},
 };
 module_platform_driver(i3c_hci_driver);
-- 
2.25.1

Re: [PATCH v3 1/5] i3c: mipi-i3c-hci: Add MIPI0100 ACPI ID to the I3C Support List

[kernel test robot]

Hi Shyam,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.11-rc2 next-20240806]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Shyam-Sundar-S-K/i3c-mipi-i3c-hci-Add-MIPI0100-ACPI-ID-to-the-I3C-Support-List/20240806-165640
base:   linus/master
patch link:    https://lore.kernel.org/r/20240806075843.277969-2-Shyam-sundar.S-k%40amd.com
patch subject: [PATCH v3 1/5] i3c: mipi-i3c-hci: Add MIPI0100 ACPI ID to the I3C Support List
config: hexagon-randconfig-001-20240806 (https://download.01.org/0day-ci/archive/20240807/202408070758.Twn4OAwy-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 423aec6573df4424f90555468128e17073ddc69e)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240807/202408070758.Twn4OAwy-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408070758.Twn4OAwy-lkp@intel.com/

All errors (new ones prefixed by >>, old ones prefixed by <<):

WARNING: modpost: missing MODULE_DESCRIPTION() in lib/test_objpool.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/zlib_inflate/zlib_inflate.o
>> ERROR: modpost: drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci: sizeof(struct platform_device_id)=24 is not a modulo of the size of section __mod_platform__<identifier>_device_table=56.
>> Fix definition of struct platform_device_id in mod_devicetable.h

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v3 2/5] i3c: mipi-i3c-hci: Add a quirk to set PIO mode

[Shyam Sundar S K]

The AMD HCI controller currently only supports PIO mode but exposes DMA
rings to the OS, which leads to the controller being configured in DMA
mode. To address this, add a quirk to avoid configuring the controller in
DMA mode and default to PIO mode.

Additionally, introduce a generic quirk infrastructure to the mipi-i3c-hci
driver to facilitate seamless future quirk additions.

Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Co-developed-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/i3c/master/mipi-i3c-hci/Makefile     |  3 ++-
 drivers/i3c/master/mipi-i3c-hci/core.c       | 15 ++++++++++++++-
 drivers/i3c/master/mipi-i3c-hci/hci.h        |  3 +++
 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c | 20 ++++++++++++++++++++
 4 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c

diff --git a/drivers/i3c/master/mipi-i3c-hci/Makefile b/drivers/i3c/master/mipi-i3c-hci/Makefile
index a658e7b8262c..1f8cd5c48fde 100644
--- a/drivers/i3c/master/mipi-i3c-hci/Makefile
+++ b/drivers/i3c/master/mipi-i3c-hci/Makefile
@@ -3,4 +3,5 @@
 obj-$(CONFIG_MIPI_I3C_HCI)		+= mipi-i3c-hci.o
 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
+					   dat_v1.o dct_v1.o \
+					   hci_quirks.o
diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index 5ef848833a81..7843a3ac2121 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -33,6 +33,7 @@
 #define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
 
 #define HCI_VERSION			0x00	/* HCI Version (in BCD) */
+#define HCI_VERSION_V1			0x100	/* MIPI HCI Version number V1.0 */
 
 #define HC_CONTROL			0x04
 #define HC_CONTROL_BUS_ENABLE		BIT(31)
@@ -753,6 +754,14 @@ static int i3c_hci_init(struct i3c_hci *hci)
 		return -EINVAL;
 	}
 
+	/* Initialize quirks for AMD platforms */
+	amd_i3c_hci_quirks_init(hci);
+
+	regval = reg_read(HCI_VERSION);
+
+	if (hci->quirks & HCI_QUIRK_PIO_MODE)
+		hci->RHS_regs = NULL;
+
 	/* Try activating DMA operations first */
 	if (hci->RHS_regs) {
 		reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE);
@@ -768,7 +777,11 @@ static int i3c_hci_init(struct i3c_hci *hci)
 	/* If no DMA, try PIO */
 	if (!hci->io && hci->PIO_regs) {
 		reg_set(HC_CONTROL, HC_CONTROL_PIO_MODE);
-		if (!(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {
+		/*
+		 * HC_CONTROL_PIO_MODE bit not present in HC_CONTROL register w.r.t V1.0
+		 * specification. So skip checking PIO_MODE bit status
+		 */
+		if (regval > HCI_VERSION_V1 && !(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {
 			dev_err(&hci->master.dev, "DMA mode is stuck\n");
 			ret = -EIO;
 		} else {
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index f94d95e024be..91e8a3833f3d 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -135,6 +135,7 @@ struct i3c_hci_dev_data {
 
 /* list of quirks */
 #define HCI_QUIRK_RAW_CCC	BIT(1)	/* CCC framing must be explicit */
+#define HCI_QUIRK_PIO_MODE	BIT(2)  /* Set PIO mode for AMD platforms */
 
 
 /* global functions */
@@ -142,4 +143,6 @@ void mipi_i3c_hci_resume(struct i3c_hci *hci);
 void mipi_i3c_hci_pio_reset(struct i3c_hci *hci);
 void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci);
 
+void amd_i3c_hci_quirks_init(struct i3c_hci *hci);
+
 #endif
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
new file mode 100644
index 000000000000..8a8fbd697175
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * I3C HCI Quirks
+ *
+ * Copyright 2024 Advanced Micro Devices, Inc.
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ *			Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
+ */
+
+#include <linux/i3c/master.h>
+#include "hci.h"
+
+void amd_i3c_hci_quirks_init(struct i3c_hci *hci)
+{
+#if defined(CONFIG_X86)
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+		hci->quirks |= HCI_QUIRK_PIO_MODE;
+#endif
+}
-- 
2.25.1

Re: [PATCH v3 2/5] i3c: mipi-i3c-hci: Add a quirk to set PIO mode

[Shyam Sundar S K]

On 8/6/2024 13:28, Shyam Sundar S K wrote:
> The AMD HCI controller currently only supports PIO mode but exposes DMA
> rings to the OS, which leads to the controller being configured in DMA
> mode. To address this, add a quirk to avoid configuring the controller in
> DMA mode and default to PIO mode.
> 
> Additionally, introduce a generic quirk infrastructure to the mipi-i3c-hci
> driver to facilitate seamless future quirk additions.
> 
> Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
> Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
> Co-developed-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
> Signed-off-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> ---
>  drivers/i3c/master/mipi-i3c-hci/Makefile     |  3 ++-
>  drivers/i3c/master/mipi-i3c-hci/core.c       | 15 ++++++++++++++-
>  drivers/i3c/master/mipi-i3c-hci/hci.h        |  3 +++
>  drivers/i3c/master/mipi-i3c-hci/hci_quirks.c | 20 ++++++++++++++++++++
>  4 files changed, 39 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
> 
> diff --git a/drivers/i3c/master/mipi-i3c-hci/Makefile b/drivers/i3c/master/mipi-i3c-hci/Makefile
> index a658e7b8262c..1f8cd5c48fde 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/Makefile
> +++ b/drivers/i3c/master/mipi-i3c-hci/Makefile
> @@ -3,4 +3,5 @@
>  obj-$(CONFIG_MIPI_I3C_HCI)		+= mipi-i3c-hci.o
>  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
> +					   dat_v1.o dct_v1.o \
> +					   hci_quirks.o
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index 5ef848833a81..7843a3ac2121 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -33,6 +33,7 @@
>  #define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
>  
>  #define HCI_VERSION			0x00	/* HCI Version (in BCD) */
> +#define HCI_VERSION_V1			0x100	/* MIPI HCI Version number V1.0 */
>  
>  #define HC_CONTROL			0x04
>  #define HC_CONTROL_BUS_ENABLE		BIT(31)
> @@ -753,6 +754,14 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  		return -EINVAL;
>  	}
>  
> +	/* Initialize quirks for AMD platforms */
> +	amd_i3c_hci_quirks_init(hci);
> +
> +	regval = reg_read(HCI_VERSION);
> +
> +	if (hci->quirks & HCI_QUIRK_PIO_MODE)
> +		hci->RHS_regs = NULL;
> +
>  	/* Try activating DMA operations first */
>  	if (hci->RHS_regs) {
>  		reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE);
> @@ -768,7 +777,11 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	/* If no DMA, try PIO */
>  	if (!hci->io && hci->PIO_regs) {
>  		reg_set(HC_CONTROL, HC_CONTROL_PIO_MODE);
> -		if (!(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {
> +		/*
> +		 * HC_CONTROL_PIO_MODE bit not present in HC_CONTROL register w.r.t V1.0
> +		 * specification. So skip checking PIO_MODE bit status
> +		 */
> +		if (regval > HCI_VERSION_V1 && !(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {

Jarkko, Apologies. I missed to address your comment on splitting the
version check and quirk stuff separately. Will do a resend, kindly
ignore this version.

Thanks,
Shyam


>  			dev_err(&hci->master.dev, "DMA mode is stuck\n");
>  			ret = -EIO;
>  		} else {
> diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
> index f94d95e024be..91e8a3833f3d 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/hci.h
> +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
> @@ -135,6 +135,7 @@ struct i3c_hci_dev_data {
>  
>  /* list of quirks */
>  #define HCI_QUIRK_RAW_CCC	BIT(1)	/* CCC framing must be explicit */
> +#define HCI_QUIRK_PIO_MODE	BIT(2)  /* Set PIO mode for AMD platforms */
>  
>  
>  /* global functions */
> @@ -142,4 +143,6 @@ void mipi_i3c_hci_resume(struct i3c_hci *hci);
>  void mipi_i3c_hci_pio_reset(struct i3c_hci *hci);
>  void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci);
>  
> +void amd_i3c_hci_quirks_init(struct i3c_hci *hci);
> +
>  #endif
> diff --git a/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
> new file mode 100644
> index 000000000000..8a8fbd697175
> --- /dev/null
> +++ b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
> @@ -0,0 +1,20 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * I3C HCI Quirks
> + *
> + * Copyright 2024 Advanced Micro Devices, Inc.
> + *
> + * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> + *			Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
> + */
> +
> +#include <linux/i3c/master.h>
> +#include "hci.h"
> +
> +void amd_i3c_hci_quirks_init(struct i3c_hci *hci)
> +{
> +#if defined(CONFIG_X86)
> +	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
> +		hci->quirks |= HCI_QUIRK_PIO_MODE;
> +#endif
> +}

[PATCH v3 3/5] i3c: mipi-i3c-hci: Relocate helper macros to HCI header file

[Shyam Sundar S K]

The reg_* helper macros are currently limited to core.c. Moving them to
hci.h will allow their functionality to be utilized in other files outside
of core.c.

Co-developed-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c | 6 ------
 drivers/i3c/master/mipi-i3c-hci/hci.h  | 5 +++++
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index 7843a3ac2121..5c4fcb740856 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -12,7 +12,6 @@
 #include <linux/errno.h>
 #include <linux/i3c/master.h>
 #include <linux/interrupt.h>
-#include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -27,11 +26,6 @@
  * Host Controller Capabilities and Operation Registers
  */
 
-#define reg_read(r)		readl(hci->base_regs + (r))
-#define reg_write(r, v)		writel(v, hci->base_regs + (r))
-#define reg_set(r, v)		reg_write(r, reg_read(r) | (v))
-#define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
-
 #define HCI_VERSION			0x00	/* HCI Version (in BCD) */
 #define HCI_VERSION_V1			0x100	/* MIPI HCI Version number V1.0 */
 
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index 91e8a3833f3d..2b7560149520 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -10,6 +10,7 @@
 #ifndef HCI_H
 #define HCI_H
 
+#include <linux/io.h>
 
 /* Handy logging macro to save on line length */
 #define DBG(x, ...) pr_devel("%s: " x "\n", __func__, ##__VA_ARGS__)
@@ -26,6 +27,10 @@
 #define W2_BIT_(x)  BIT((x) - 64)
 #define W3_BIT_(x)  BIT((x) - 96)
 
+#define reg_read(r)		readl(hci->base_regs + (r))
+#define reg_write(r, v)		writel(v, hci->base_regs + (r))
+#define reg_set(r, v)		reg_write(r, reg_read(r) | (v))
+#define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
 
 struct hci_cmd_ops;
 
-- 
2.25.1

[PATCH v3 4/5] i3c: mipi-i3c-hci: Add a quirk to set timing parameters

[Shyam Sundar S K]

The AMD HCI controller is currently unstable at 12.5 MHz. To address this,
a quirk is added to configure the clock rate to 9 MHz as a workaround,
with proportional adjustments to the Open-Drain (OD) and Push-Pull (PP)
values.

Co-developed-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c       |  4 ++++
 drivers/i3c/master/mipi-i3c-hci/hci.h        |  2 ++
 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c | 25 +++++++++++++++++++-
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index 5c4fcb740856..baec2c42e0e0 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -791,6 +791,10 @@ static int i3c_hci_init(struct i3c_hci *hci)
 		return ret;
 	}
 
+	/* Configure OD and PP timings for AMD platforms */
+	if (hci->quirks & HCI_QUIRK_OD_PP_TIMING)
+		amd_set_od_pp_timing(hci);
+
 	return 0;
 }
 
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index 2b7560149520..e1a65cfb43c8 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -141,6 +141,7 @@ struct i3c_hci_dev_data {
 /* list of quirks */
 #define HCI_QUIRK_RAW_CCC	BIT(1)	/* CCC framing must be explicit */
 #define HCI_QUIRK_PIO_MODE	BIT(2)  /* Set PIO mode for AMD platforms */
+#define HCI_QUIRK_OD_PP_TIMING		BIT(3)  /* Set OD and PP timings for AMD platforms */
 
 
 /* global functions */
@@ -149,5 +150,6 @@ void mipi_i3c_hci_pio_reset(struct i3c_hci *hci);
 void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci);
 
 void amd_i3c_hci_quirks_init(struct i3c_hci *hci);
+void amd_set_od_pp_timing(struct i3c_hci *hci);
 
 #endif
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
index 8a8fbd697175..a222bfab0676 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
+++ b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
@@ -11,10 +11,33 @@
 #include <linux/i3c/master.h>
 #include "hci.h"
 
+/* Timing registers */
+#define HCI_SCL_I3C_OD_TIMING          0x214
+#define HCI_SCL_I3C_PP_TIMING          0x218
+#define HCI_SDA_HOLD_SWITCH_DLY_TIMING 0x230
+
+/* Timing values to configure 9MHz frequency */
+#define AMD_SCL_I3C_OD_TIMING          0x00cf00cf
+#define AMD_SCL_I3C_PP_TIMING          0x00160016
+
 void amd_i3c_hci_quirks_init(struct i3c_hci *hci)
 {
 #if defined(CONFIG_X86)
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
 		hci->quirks |= HCI_QUIRK_PIO_MODE;
+		hci->quirks |= HCI_QUIRK_OD_PP_TIMING;
+	}
 #endif
 }
+
+void amd_set_od_pp_timing(struct i3c_hci *hci)
+{
+	u32 data;
+
+	reg_write(HCI_SCL_I3C_OD_TIMING, AMD_SCL_I3C_OD_TIMING);
+	reg_write(HCI_SCL_I3C_PP_TIMING, AMD_SCL_I3C_PP_TIMING);
+	data = reg_read(HCI_SDA_HOLD_SWITCH_DLY_TIMING);
+	/* Configure maximum TX hold time */
+	data |= W0_MASK(18, 16);
+	reg_write(HCI_SDA_HOLD_SWITCH_DLY_TIMING, data);
+}
-- 
2.25.1

[PATCH v3 5/5] i3c: mipi-i3c-hci: Add a quirk to set Response buffer threshold

[Shyam Sundar S K]

The current driver sets the response buffer threshold value to 1
(N+1, 2 DWORDS) in the QUEUE THRESHOLD register. However, the AMD
I3C controller only generates interrupts when the response buffer
threshold value is set to 0 (1 DWORD).

Therefore, a quirk is added to set the response buffer threshold value
to 0.

Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Co-developed-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c       |  4 ++++
 drivers/i3c/master/mipi-i3c-hci/hci.h        |  2 ++
 drivers/i3c/master/mipi-i3c-hci/hci_quirks.c | 12 ++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index baec2c42e0e0..248f07f41c16 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -147,6 +147,10 @@ static int i3c_hci_bus_init(struct i3c_master_controller *m)
 	if (ret)
 		return ret;
 
+	/* Set RESP_BUF_THLD to 0(n) to get 1(n+1) response */
+	if (hci->quirks & HCI_QUIRK_RESP_BUF_THLD)
+		amd_set_resp_buf_thld(hci);
+
 	reg_set(HC_CONTROL, HC_CONTROL_BUS_ENABLE);
 	DBG("HC_CONTROL = %#x", reg_read(HC_CONTROL));
 
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index e1a65cfb43c8..b6f1b97f9e04 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -142,6 +142,7 @@ struct i3c_hci_dev_data {
 #define HCI_QUIRK_RAW_CCC	BIT(1)	/* CCC framing must be explicit */
 #define HCI_QUIRK_PIO_MODE	BIT(2)  /* Set PIO mode for AMD platforms */
 #define HCI_QUIRK_OD_PP_TIMING		BIT(3)  /* Set OD and PP timings for AMD platforms */
+#define HCI_QUIRK_RESP_BUF_THLD		BIT(4)  /* Set resp buf thld to 0 for AMD platforms */
 
 
 /* global functions */
@@ -151,5 +152,6 @@ void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci);
 
 void amd_i3c_hci_quirks_init(struct i3c_hci *hci);
 void amd_set_od_pp_timing(struct i3c_hci *hci);
+void amd_set_resp_buf_thld(struct i3c_hci *hci);
 
 #endif
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
index a222bfab0676..43210882ec4d 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
+++ b/drivers/i3c/master/mipi-i3c-hci/hci_quirks.c
@@ -20,12 +20,15 @@
 #define AMD_SCL_I3C_OD_TIMING          0x00cf00cf
 #define AMD_SCL_I3C_PP_TIMING          0x00160016
 
+#define QUEUE_THLD_CTRL		0xD0
+
 void amd_i3c_hci_quirks_init(struct i3c_hci *hci)
 {
 #if defined(CONFIG_X86)
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
 		hci->quirks |= HCI_QUIRK_PIO_MODE;
 		hci->quirks |= HCI_QUIRK_OD_PP_TIMING;
+		hci->quirks |= HCI_QUIRK_RESP_BUF_THLD;
 	}
 #endif
 }
@@ -41,3 +44,12 @@ void amd_set_od_pp_timing(struct i3c_hci *hci)
 	data |= W0_MASK(18, 16);
 	reg_write(HCI_SDA_HOLD_SWITCH_DLY_TIMING, data);
 }
+
+void amd_set_resp_buf_thld(struct i3c_hci *hci)
+{
+	u32 data;
+
+	data = reg_read(QUEUE_THLD_CTRL);
+	data = data & ~W0_MASK(15, 8);
+	reg_write(QUEUE_THLD_CTRL, data);
+}
-- 
2.25.1