From: linux-kernel-dev@aliel•fr
To: Lee Jones <lee@kernel•org>
Cc: Neil Armstrong <neil.armstrong@linaro•org>,
Rob Herring <robh@kernel•org>,
Krzysztof Kozlowski <krzk+dt@kernel•org>,
Conor Dooley <conor+dt@kernel•org>,
Andi Shyti <andi.shyti@kernel•org>,
Kevin Hilman <khilman@baylibre•com>,
Jerome Brunet <jbrunet@baylibre•com>,
Martin Blumenstingl <martin.blumenstingl@googlemail•com>,
Beniamino Galvani <b.galvani@gmail•com>,
"Rafael J. Wysocki" <rafael@kernel•org>,
Daniel Lezcano <daniel.lezcano@kernel•org>,
Zhang Rui <rui.zhang@intel•com>,
Lukasz Luba <lukasz.luba@arm•com>,
Liam Girdwood <lgirdwood@gmail•com>,
Mark Brown <broonie@kernel•org>,
linux-amlogic@lists•infradead.org, devicetree@vger•kernel.org,
linux-kernel@vger•kernel.org, linux-i2c@vger•kernel.org,
linux-arm-kernel@lists•infradead.org, linux-pm@vger•kernel.org
Subject: Re: [PATCH v6 4/8] mfd: khadas-mcu: Add support for VIM4 MCU variant
Date: Wed, 3 Jun 2026 19:50:22 +0200 [thread overview]
Message-ID: <178b09d3-4e05-4f0c-b598-fa37c7a2503c@aliel.fr> (raw)
In-Reply-To: <20260527145322.GB671544@google.com>
On 5/27/26 4:53 PM, Lee Jones wrote:
> On Sat, 16 May 2026, Ronald Claveau via B4 Relay wrote:
>
>> From: Ronald Claveau <linux-kernel-dev@aliel•fr>
>>
>> Refactor probe() to use per-variant khadas_mcu_data
>> instead of hardcoded globals.
>>
>> Add dedicated regmap configuration and device data for the VIM4 MCU,
>> with its own volatile/writeable registers.
>>
>> Add the fan control register
>> (0–100 levels vs 0–3 for previous supported boards).
>>
>> Add a new compatible string "khadas,vim4-mcu".
>>
>> Reviewed-by: Neil Armstrong <neil.armstrong@linaro•org>
>> Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel•fr>
>> ---
>> drivers/mfd/khadas-mcu.c | 119 +++++++++++++++++++++++++++++++++++++++++------
>> 1 file changed, 104 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/mfd/khadas-mcu.c b/drivers/mfd/khadas-mcu.c
>> index ba981a7886921..7bc538232a445 100644
>> --- a/drivers/mfd/khadas-mcu.c
>> +++ b/drivers/mfd/khadas-mcu.c
>> @@ -75,15 +75,91 @@ static const struct regmap_config khadas_mcu_regmap_config = {
>> .cache_type = REGCACHE_MAPLE,
>> };
>>
>> -static struct mfd_cell khadas_mcu_fan_cells[] = {
>> +static const struct khadas_mcu_fan_pdata khadas_mcu_fan_pdata = {
>> + .fan_reg = KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
>> + .max_level = 3, /* Fan speed: 0 = off, 1 = low, 2 = medium, 3 = high */
>> +};
>> +
>> +static const struct mfd_cell khadas_mcu_fan_cells[] = {
>> /* VIM1/2 Rev13+ and VIM3 only */
>> - { .name = "khadas-mcu-fan-ctrl", },
>> + {
>> + .name = "khadas-mcu-fan-ctrl",
>> + .platform_data = &khadas_mcu_fan_pdata,
>> + .pdata_size = sizeof(khadas_mcu_fan_pdata),
>> + },
>> };
>>
>> -static struct mfd_cell khadas_mcu_cells[] = {
>> +static const struct mfd_cell khadas_mcu_cells[] = {
>> { .name = "khadas-mcu-user-mem", },
>> };
>>
>> +static const struct khadas_mcu_data khadas_mcu_data = {
>> + .regmap_config = &khadas_mcu_regmap_config,
>> + .cells = khadas_mcu_cells,
>> + .ncells = ARRAY_SIZE(khadas_mcu_cells),
>> + .fan_cells = khadas_mcu_fan_cells,
>> + .nfan_cells = ARRAY_SIZE(khadas_mcu_fan_cells),
>> +};
>
> Let's not over-complicate things please.
>
> You can do all of this with local variables inside khadas_mcu_probe()
> and omit the terribly named khadas_mcu_data structure entirely.
>
Ok thanks, I will send a new version according to your feedback.
>> +static bool khadas_mcu_vim4_reg_volatile(struct device *dev, unsigned int reg)
>> +{
>> + switch (reg) {
>> + case KHADAS_MCU_PWR_OFF_CMD_REG:
>> + case KHADAS_MCU_VIM4_REST_CONF_REG:
>> + case KHADAS_MCU_WOL_INIT_START_REG:
>> + case KHADAS_MCU_VIM4_LED_ON_RAM_REG:
>> + case KHADAS_MCU_VIM4_FAN_CTRL_REG:
>> + case KHADAS_MCU_VIM4_WDT_EN_REG:
>> + case KHADAS_MCU_VIM4_SYS_RST_REG:
>> + return true;
>> + default:
>> + return false;
>> + }
>> +}
>> +
>> +static bool khadas_mcu_vim4_reg_writeable(struct device *dev, unsigned int reg)
>> +{
>> + switch (reg) {
>> + case KHADAS_MCU_VERSION_0_REG:
>> + case KHADAS_MCU_VERSION_1_REG:
>> + case KHADAS_MCU_SHUTDOWN_NORMAL_STATUS_REG:
>> + return false;
>> + default:
>> + return true;
>> + }
>> +}
>> +
>> +static const struct regmap_config khadas_mcu_vim4_regmap_config = {
>> + .reg_bits = 8,
>> + .reg_stride = 1,
>> + .val_bits = 8,
>> + .max_register = KHADAS_MCU_VIM4_SYS_RST_REG,
>> + .volatile_reg = khadas_mcu_vim4_reg_volatile,
>> + .writeable_reg = khadas_mcu_vim4_reg_writeable,
>> + .cache_type = REGCACHE_MAPLE,
>> +};
>> +
>> +static const struct khadas_mcu_fan_pdata khadas_vim4_fan_pdata = {
>> + .fan_reg = KHADAS_MCU_VIM4_FAN_CTRL_REG,
>> + .max_level = 0x64,
>> +};
>> +
>> +static const struct mfd_cell khadas_mcu_vim4_cells[] = {
>> + {
>> + .name = "khadas-mcu-fan-ctrl",
>> + .platform_data = &khadas_vim4_fan_pdata,
>> + .pdata_size = sizeof(khadas_vim4_fan_pdata),
>> + },
>> +};
>> +
>> +static const struct khadas_mcu_data khadas_vim4_mcu_data = {
>> + .regmap_config = &khadas_mcu_vim4_regmap_config,
>> + .cells = NULL,
>> + .ncells = 0,
>> + .fan_cells = khadas_mcu_vim4_cells,
>> + .nfan_cells = ARRAY_SIZE(khadas_mcu_vim4_cells),
>> +};
>> +
>> static int khadas_mcu_probe(struct i2c_client *client)
>> {
>> struct device *dev = &client->dev;
>> @@ -94,28 +170,40 @@ static int khadas_mcu_probe(struct i2c_client *client)
>> if (!ddata)
>> return -ENOMEM;
>>
>> + switch ((uintptr_t)i2c_get_match_data(client)) {
>> + case KHADAS_MCU_GENERIC:
>> + ddata->data = &khadas_mcu_data;
>> + break;
>> + case KHADAS_MCU_VIM4:
>> + ddata->data = &khadas_vim4_mcu_data;
>> + break;
>> + default:
>> + return -ENODEV;
>> + }
>> +
>> i2c_set_clientdata(client, ddata);
>>
>> ddata->dev = dev;
>>
>> - ddata->regmap = devm_regmap_init_i2c(client, &khadas_mcu_regmap_config);
>> + ddata->regmap = devm_regmap_init_i2c(client, ddata->data->regmap_config);
>> if (IS_ERR(ddata->regmap)) {
>> ret = PTR_ERR(ddata->regmap);
>> - dev_err(dev, "Failed to allocate register map: %d\n", ret);
>> - return ret;
>> + return dev_err_probe(dev, ret, "Failed to allocate register map\n");
>> }
>>
>> - ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
>> - khadas_mcu_cells,
>> - ARRAY_SIZE(khadas_mcu_cells),
>> - NULL, 0, NULL);
>> - if (ret)
>> - return ret;
>> + if (ddata->data->cells && ddata->data->ncells) {
>> + ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
>> + ddata->data->cells,
>> + ddata->data->ncells,
>> + NULL, 0, NULL);
>> + if (ret)
>> + return ret;
>> + }
>>
>> if (of_property_present(dev->of_node, "#cooling-cells"))
>> return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
>> - khadas_mcu_fan_cells,
>> - ARRAY_SIZE(khadas_mcu_fan_cells),
>> + ddata->data->fan_cells,
>> + ddata->data->nfan_cells,
>> NULL, 0, NULL);
>>
>> return 0;
>> @@ -123,7 +211,8 @@ static int khadas_mcu_probe(struct i2c_client *client)
>>
>> #ifdef CONFIG_OF
>> static const struct of_device_id khadas_mcu_of_match[] = {
>> - { .compatible = "khadas,mcu", },
>> + { .compatible = "khadas,mcu", .data = (void *)KHADAS_MCU_GENERIC },
>> + { .compatible = "khadas,vim4-mcu", .data = (void *)KHADAS_MCU_VIM4 },
>> {},
>> };
>> MODULE_DEVICE_TABLE(of, khadas_mcu_of_match);
>>
>> --
>> 2.49.0
>>
>>
>
--
Best regards,
Ronald
next prev parent reply other threads:[~2026-06-03 17:50 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-16 17:17 [PATCH v6 0/8] Add VIM4 MCU/FAN support Ronald Claveau via B4 Relay
2026-05-16 17:17 ` [PATCH v6 1/8] dt-bindings: mfd: khadas: Add new compatible for Khadas VIM4 MCU Ronald Claveau via B4 Relay
2026-05-16 17:17 ` [PATCH v6 2/8] dt-bindings: i2c: amlogic: Add compatible for T7 SOC Ronald Claveau via B4 Relay
2026-05-16 17:17 ` [PATCH v6 3/8] mfd: khadas-mcu: Add per-variant configuration infrastructure and VIM4 support Ronald Claveau via B4 Relay
2026-05-27 14:54 ` Lee Jones
2026-05-16 17:17 ` [PATCH v6 4/8] mfd: khadas-mcu: Add support for VIM4 MCU variant Ronald Claveau via B4 Relay
2026-05-27 14:53 ` Lee Jones
2026-06-03 17:50 ` linux-kernel-dev [this message]
2026-05-16 17:17 ` [PATCH v6 5/8] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support Ronald Claveau via B4 Relay
2026-05-16 17:17 ` [PATCH v6 6/8] arm64: dts: amlogic: t7: Add i2c pinctrl node Ronald Claveau via B4 Relay
2026-05-16 17:17 ` [PATCH v6 7/8] arm64: dts: amlogic: t7: Add i2c controller node Ronald Claveau via B4 Relay
2026-05-16 17:17 ` [PATCH v6 8/8] arm64: dts: amlogic: t7: khadas-vim4: Add i2c MCU fan node Ronald Claveau via B4 Relay
2026-05-18 14:17 ` [PATCH v6 0/8] Add VIM4 MCU/FAN support Neil Armstrong
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