Message-ID: <aMwy9MQOf3pG4Fvw@lizhi-Precision-Tower-5810>
Date: Thu, 18 Sep 2025 12:27:32 -0400
From: Frank Li <Frank.li@....com>
To: Durai Manickam KR <durai.manickamkr@...rochip.com>
Cc: linux-i3c@...ts.infradead.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, alexandre.belloni@...tlin.com,
	robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org,
	balamanikandan.gunasundar@...rochip.com,
	nicolas.ferre@...rochip.com
Subject: Re: [PATCH 2/4] i3c: mipi-i3c-hci: add microchip sama7d65 SoC

On Thu, Sep 18, 2025 at 03:24:27PM +0530, Durai Manickam KR wrote:
> Add support for microchip sama7d65 SoC I3C HCI master only IP.
> Features tested and supported :
>            Standard CCC commands.
>            I3C SDR mode private transfers in PIO mode.
>            I2C transfers in PIO mode.
>            Pure bus mode and mixed bus mode.
>
> Signed-off-by: Durai Manickam KR <durai.manickamkr@...rochip.com>
> ---
>  drivers/i3c/master/mipi-i3c-hci/Makefile      |  3 +-
>  drivers/i3c/master/mipi-i3c-hci/core.c        | 28 ++++++++++++
>  drivers/i3c/master/mipi-i3c-hci/hci.h         | 12 ++++++
>  .../i3c/master/mipi-i3c-hci/hci_quirks_mchp.c | 43 +++++++++++++++++++
>  4 files changed, 85 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/i3c/master/mipi-i3c-hci/hci_quirks_mchp.c
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/Makefile b/drivers/i3c/master/mipi-i3c-hci/Makefile
> index e3d3ef757035..f463afc4566a 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/Makefile
> +++ b/drivers/i3c/master/mipi-i3c-hci/Makefile
> @@ -4,5 +4,6 @@ obj-$(CONFIG_MIPI_I3C_HCI)		+= mipi-i3c-hci.o
>  mipi-i3c-hci-y				:= core.o ext_caps.o pio.o dma.o \
>  					   cmd_v1.o cmd_v2.o \
>  					   dat_v1.o dct_v1.o \
> -					   hci_quirks.o
> +					   hci_quirks.o \
> +					   hci_quirks_mchp.o
>  obj-$(CONFIG_MIPI_I3C_HCI_PCI)		+= mipi-i3c-hci-pci.o
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index 60f1175f1f37..cb0673d62c03 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -8,6 +8,7 @@
>   */
>
>  #include <linux/bitfield.h>
> +#include <linux/clk.h>
>  #include <linux/device.h>
>  #include <linux/errno.h>
>  #include <linux/i3c/master.h>
> @@ -651,6 +652,9 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	hci->DAT_regs = offset ? hci->base_regs + offset : NULL;
>  	hci->DAT_entries = FIELD_GET(DAT_TABLE_SIZE, regval);
>  	hci->DAT_entry_size = FIELD_GET(DAT_ENTRY_SIZE, regval) ? 0 : 8;
> +	/* Microchip SAMA7D65 SoC doesnot support DAT entry size bits in the DAT section offset register */
> +	if (hci->quirks & MCHP_HCI_QUIRK_SAMA7D65)
> +		hci->DAT_entry_size = 8;

#define MCHP_HCI_QUIRK_FIX_DATA_ENTRY_SIZE_8

	if (hci->quirks & MCHP_HCI_QUIRK_FIX_DATA_ENTRY_SIZE_8)
		hci->DAT_entry_size = 8;
	else
		hci->DAT_entry_size = FIELD_GET(DAT_ENTRY_SIZE, regval) ? 0 : 8;

in case other vendor have similar problem.

>  	if (size_in_dwords)
>  		hci->DAT_entries = 4 * hci->DAT_entries / hci->DAT_entry_size;
>  	dev_info(&hci->master.dev, "DAT: %u %u-bytes entries at offset %#x\n",
> @@ -661,6 +665,9 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	hci->DCT_regs = offset ? hci->base_regs + offset : NULL;
>  	hci->DCT_entries = FIELD_GET(DCT_TABLE_SIZE, regval);
>  	hci->DCT_entry_size = FIELD_GET(DCT_ENTRY_SIZE, regval) ? 0 : 16;
> +	/* Microchip SAMA7D65 SoC doesnot support DCT entry size bits in the DCT section offset register */
> +	if (hci->quirks & MCHP_HCI_QUIRK_SAMA7D65)
> +		hci->DCT_entry_size = 16;

The same here.

>  	if (size_in_dwords)
>  		hci->DCT_entries = 4 * hci->DCT_entries / hci->DCT_entry_size;
>  	dev_info(&hci->master.dev, "DCT: %u %u-bytes entries at offset %#x\n",
> @@ -753,6 +760,10 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	if (hci->quirks & HCI_QUIRK_PIO_MODE)
>  		hci->RHS_regs = NULL;
>
> +	/* Microchip SAMA7d65 SoC supports only PIO mode */
> +	if (hci->quirks & MCHP_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);
> @@ -788,6 +799,10 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	if (hci->quirks & HCI_QUIRK_OD_PP_TIMING)
>  		amd_set_od_pp_timing(hci);

It is worth to add a callback set_od_pp_timing() instead of use quirks.

You can create patch change existed amd one, then add mchp one.

> +	/* Configure OD and PP timings for Microchip platforms */
> +	if (hci->quirks & MCHP_HCI_QUIRK_OD_PP_TIMING)
> +		mchp_set_od_pp_timing(hci);
> +
>  	return 0;
>  }
>
> @@ -803,6 +818,16 @@ static int i3c_hci_probe(struct platform_device *pdev)
>  	if (IS_ERR(hci->base_regs))
>  		return PTR_ERR(hci->base_regs);
>
> +#if defined(CONFIG_SOC_SAMA7D65)
> +	hci->gclk = devm_clk_get_enabled(&pdev->dev, "gclk");
> +	if (IS_ERR(hci->gclk))
> +		return PTR_ERR(hci->gclk);
> +
> +	hci->pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
> +	if (IS_ERR(hci->pclk))
> +		return PTR_ERR(hci->pclk);
> +#endif
> +

Use devm_clk_bulk_get_all_enabled() can be comaptible other platform.


>  	platform_set_drvdata(pdev, hci);
>  	/* temporary for dev_printk's, to be replaced in i3c_master_register */
>  	hci->master.dev.init_name = dev_name(&pdev->dev);
> @@ -836,6 +861,9 @@ static void i3c_hci_remove(struct platform_device *pdev)
>
>  static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
>  	{ .compatible = "mipi-i3c-hci", },
> +	{ .compatible = "mchp,sama7d65-i3c-hci",
> +	  .data = (void *)(MCHP_HCI_QUIRK_PIO_MODE | MCHP_HCI_QUIRK_OD_PP_TIMING |
> +			   MCHP_HCI_QUIRK_RESP_BUF_THLD | MCHP_HCI_QUIRK_SAMA7D65) },


don't suggest use cast this to pointer. You can define struct

struct mipi_csi_drvdata
{
	void (*set_op_pp_timing)();
	void **set_resp_buf_thld)();
	u32 flags;
};

static const mipi_csi_drvdata sama7d64_data = {
	.set_op_pp_timing = mchp_set_od_pp_timing;
	...
	.flags = MCHP_HCI_QUIRK_PIO_MODE;
}

.compatible = "mchp,sama7d65-i3c-hci", .data = &sama7d64_data

>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
> diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
> index 69ea1d10414b..e57f8d85402c 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/hci.h
> +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
> @@ -37,6 +37,10 @@ struct hci_cmd_ops;
>  /* Our main structure */
>  struct i3c_hci {
>  	struct i3c_master_controller master;
> +#if defined(CONFIG_SOC_SAMA7D65)
> +	struct clk *gclk;
> +	struct clk *pclk;
> +#endif

Needn't it because both are only used at probe funciton.

Frank

>  	void __iomem *base_regs;
>  	void __iomem *DAT_regs;
>  	void __iomem *DCT_regs;
> @@ -144,6 +148,12 @@ struct i3c_hci_dev_data {
>  #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 */
>
> +/* list of quirks for Microchip platforms */
> +#define MCHP_HCI_QUIRK_PIO_MODE		BIT(2)  /* Set PIO mode */
> +#define MCHP_HCI_QUIRK_OD_PP_TIMING	BIT(3)  /* Set OD and PP timings */
> +#define MCHP_HCI_QUIRK_RESP_BUF_THLD	BIT(4)  /* Set resp buf thld to 0 */
> +#define MCHP_HCI_QUIRK_SAMA7D65		BIT(5)  /* Set SAMA7D65 SoC specific features */
> +
>
>  /* global functions */
>  void mipi_i3c_hci_resume(struct i3c_hci *hci);
> @@ -151,5 +161,7 @@ void mipi_i3c_hci_pio_reset(struct i3c_hci *hci);
>  void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci);
>  void amd_set_od_pp_timing(struct i3c_hci *hci);
>  void amd_set_resp_buf_thld(struct i3c_hci *hci);
> +void mchp_set_od_pp_timing(struct i3c_hci *hci);
> +void mchp_set_resp_buf_thld(struct i3c_hci *hci);
>
>  #endif
> diff --git a/drivers/i3c/master/mipi-i3c-hci/hci_quirks_mchp.c b/drivers/i3c/master/mipi-i3c-hci/hci_quirks_mchp.c
> new file mode 100644
> index 000000000000..f2e54e6643c0
> --- /dev/null
> +++ b/drivers/i3c/master/mipi-i3c-hci/hci_quirks_mchp.c
> @@ -0,0 +1,43 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2025 Microchip Technology Inc. and its subsidiaries
> + *
> + * Authors: Durai Manickam KR <durai.manickamkr@...rochip.com>
> + *
> + * Microchip I3C HCI Quirks
> + */
> +
> +#include <linux/i3c/master.h>
> +#include "hci.h"
> +
> +/* Timing registers */
> +#define MCHP_HCI_SCL_I3C_OD_TIMING          0x214
> +#define MCHP_HCI_SCL_I3C_PP_TIMING          0x218
> +#define MCHP_HCI_SDA_HOLD_SWITCH_DLY_TIMING 0x230
> +
> +/* Timing values to configure 9MHz frequency */
> +#define MCHP_SCL_I3C_OD_TIMING          0x00cf00cf
> +#define MCHP_SCL_I3C_PP_TIMING          0x00160016
> +
> +#define MCHP_QUEUE_THLD_CTRL                0xD0
> +
> +void mchp_set_od_pp_timing(struct i3c_hci *hci)
> +{
> +	u32 data;
> +
> +	reg_write(MCHP_HCI_SCL_I3C_OD_TIMING, MCHP_SCL_I3C_OD_TIMING);
> +	reg_write(MCHP_HCI_SCL_I3C_PP_TIMING, MCHP_SCL_I3C_PP_TIMING);
> +	data = reg_read(MCHP_HCI_SDA_HOLD_SWITCH_DLY_TIMING);
> +	/* Configure maximum TX hold time */
> +	data |= W0_MASK(18, 16);
> +	reg_write(MCHP_HCI_SDA_HOLD_SWITCH_DLY_TIMING, data);
> +}
> +
> +void mchp_set_resp_buf_thld(struct i3c_hci *hci)
> +{
> +	u32 data;
> +
> +	data = reg_read(MCHP_QUEUE_THLD_CTRL);
> +	data = data & ~W0_MASK(15, 8);
> +	reg_write(MCHP_QUEUE_THLD_CTRL, data);
> +}
> --
> 2.34.1
>
>
> --
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> linux-i3c@...ts.infradead.org
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