Re: [PATCH v6 7/9] platform/x86: serial-multi-instantiate: Add SPI support

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 1/21/22 18:24, Stefan Binding wrote:
> Add support for spi bus in serial-multi-instantiate driver
> 
> Some peripherals can have either a I2C or a SPI connection
> to the host (but not both) but use the same HID for both
> types. So it is not possible to use the HID to determine
> whether it is I2C or SPI. The driver must check the node
> to see if it contains I2cSerialBus or SpiSerialBus entries.
> 
> For backwards-compatibility with the existing nodes I2C is
> checked first and if such entries are found ONLY I2C devices
> are created. Since some existing nodes that were already
> handled by this driver could also contain unrelated
> SpiSerialBus nodes that were previously ignored, and this
> preserves that behavior. If there is ever a need to handle
> a node where both I2C and SPI devices must be instantiated
> this can be added in future.
> 
> Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
> ---
>  drivers/platform/x86/Kconfig                  |   2 +-
>  .../platform/x86/serial-multi-instantiate.c   | 174 +++++++++++++++---
>  2 files changed, 151 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 2e656909a866..8d1eec208854 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -992,7 +992,7 @@ config TOPSTAR_LAPTOP
>  
>  config SERIAL_MULTI_INSTANTIATE
>  	tristate "Serial bus multi instantiate pseudo device driver"
> -	depends on I2C && ACPI
> +	depends on I2C && SPI && ACPI
>  	help
>  	  Some ACPI-based systems list multiple devices in a single ACPI
>  	  firmware-node. This driver will instantiate separate clients
> diff --git a/drivers/platform/x86/serial-multi-instantiate.c b/drivers/platform/x86/serial-multi-instantiate.c
> index 4cd6d72a0741..3f05385ca2cf 100644
> --- a/drivers/platform/x86/serial-multi-instantiate.c
> +++ b/drivers/platform/x86/serial-multi-instantiate.c
> @@ -14,6 +14,7 @@
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/property.h>
> +#include <linux/spi/spi.h>
>  #include <linux/types.h>
>  
>  #define IRQ_RESOURCE_TYPE	GENMASK(1, 0)
> @@ -21,15 +22,28 @@
>  #define IRQ_RESOURCE_GPIO	1
>  #define IRQ_RESOURCE_APIC	2
>  
> +enum smi_bus_type {
> +	SMI_I2C,
> +	SMI_SPI,
> +	SMI_AUTO_DETECT,
> +};
> +
>  struct smi_instance {
>  	const char *type;
>  	unsigned int flags;
>  	int irq_idx;
>  };
>  
> +struct smi_node {
> +	enum smi_bus_type bus_type;
> +	struct smi_instance instances[];
> +};
> +
>  struct smi {
>  	int i2c_num;
> +	int spi_num;
>  	struct i2c_client **i2c_devs;
> +	struct spi_device **spi_devs;
>  };
>  
>  static int smi_get_irq(struct platform_device *pdev, struct acpi_device *adev,
> @@ -59,6 +73,95 @@ static void smi_devs_unregister(struct smi *smi)
>  {
>  	while (smi->i2c_num > 0)
>  		i2c_unregister_device(smi->i2c_devs[--smi->i2c_num]);
> +
> +	while (smi->spi_num > 0)
> +		spi_unregister_device(smi->spi_devs[--smi->spi_num]);
> +}
> +
> +/**
> + * smi_spi_probe - Instantiate multiple SPI devices from inst array
> + * @pdev:	Platform device
> + * @adev:	ACPI device
> + * @smi:	Internal struct for Serial multi instantiate driver
> + * @inst_array:	Array of instances to probe
> + *
> + * Returns the number of SPI devices instantiate, Zero if none is found or a negative error code.
> + */
> +static int smi_spi_probe(struct platform_device *pdev, struct acpi_device *adev, struct smi *smi,
> +			 const struct smi_instance *inst_array)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct spi_controller *ctlr;
> +	struct spi_device *spi_dev;
> +	char name[50];
> +	int i, ret, count;
> +
> +	ret = acpi_spi_count_resources(adev);
> +	if (ret < 0)
> +		return ret;
> +	else if (!ret)
> +		return -ENODEV;
> +
> +	count = ret;
> +
> +	smi->spi_devs = devm_kcalloc(dev, count, sizeof(*smi->spi_devs), GFP_KERNEL);
> +	if (!smi->spi_devs)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < count && inst_array[i].type; i++) {
> +
> +		spi_dev = acpi_spi_device_alloc(NULL, adev, i);
> +		if (IS_ERR(spi_dev)) {
> +			ret = PTR_ERR(spi_dev);
> +			dev_err_probe(dev, ret, "failed to allocate SPI device %s from ACPI: %d\n",
> +				      dev_name(&adev->dev), ret);
> +			goto error;
> +		}
> +
> +		ctlr = spi_dev->controller;
> +
> +		strscpy(spi_dev->modalias, inst_array[i].type, sizeof(spi_dev->modalias));
> +
> +		ret = smi_get_irq(pdev, adev, &inst_array[i]);
> +		if (ret < 0) {
> +			spi_dev_put(spi_dev);
> +			goto error;
> +		}
> +		spi_dev->irq = ret;
> +
> +		snprintf(name, sizeof(name), "%s-%s-%s.%d", dev_name(&ctlr->dev), dev_name(dev),
> +			 inst_array[i].type, i);
> +		spi_dev->dev.init_name = name;
> +
> +		ret = spi_add_device(spi_dev);
> +		if (ret) {
> +			dev_err_probe(&ctlr->dev, ret,
> +				      "failed to add SPI device %s from ACPI: %d\n",
> +				      dev_name(&adev->dev), ret);
> +			spi_dev_put(spi_dev);
> +			goto error;
> +		}
> +
> +		dev_dbg(dev, "SPI device %s using chip select %u", name, spi_dev->chip_select);
> +
> +		smi->spi_devs[i] = spi_dev;
> +		smi->spi_num++;
> +	}
> +
> +	if (smi->spi_num < count) {
> +		dev_dbg(dev, "Error finding driver, idx %d\n", i);
> +		ret = -ENODEV;
> +		goto error;
> +	}
> +
> +	dev_info(dev, "Instantiated %d SPI devices.\n", smi->spi_num);
> +
> +	return 0;
> +error:
> +	smi_devs_unregister(smi);
> +
> +	return ret;
> +
>  }
>  
>  /**
> @@ -126,8 +229,8 @@ static int smi_i2c_probe(struct platform_device *pdev, struct acpi_device *adev,
>  
>  static int smi_probe(struct platform_device *pdev)
>  {
> -	const struct smi_instance *inst_array;
>  	struct device *dev = &pdev->dev;
> +	const struct smi_node *node;
>  	struct acpi_device *adev;
>  	struct smi *smi;
>  
> @@ -135,8 +238,8 @@ static int smi_probe(struct platform_device *pdev)
>  	if (!adev)
>  		return -ENODEV;
>  
> -	inst_array = device_get_match_data(dev);
> -	if (!inst_array) {
> +	node = device_get_match_data(dev);
> +	if (!node) {
>  		dev_dbg(dev, "Error ACPI match data is missing\n");
>  		return -ENODEV;
>  	}
> @@ -147,7 +250,21 @@ static int smi_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, smi);
>  
> -	return smi_i2c_probe(pdev, adev, smi, inst_array);
> +	switch (node->bus_type) {
> +	case SMI_I2C:
> +		return smi_i2c_probe(pdev, adev, smi, node->instances);
> +	case SMI_SPI:
> +		return smi_spi_probe(pdev, adev, smi, node->instances);
> +	case SMI_AUTO_DETECT:
> +		if (i2c_acpi_client_count(adev) > 0)
> +			return smi_i2c_probe(pdev, adev, smi, node->instances);
> +		else
> +			return smi_spi_probe(pdev, adev, smi, node->instances);
> +	default:
> +		break;

Please replace this break with : "return -EINVAL" (since we really
should never hit this default case).

With that fixed, please add my R-b to the next version:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> +	}
> +
> +	return 0; /* never reached */
>  }
>  
>  static int smi_remove(struct platform_device *pdev)
> @@ -159,27 +276,36 @@ static int smi_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static const struct smi_instance bsg1160_data[]  = {
> -	{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
> -	{ "bmc150_magn" },
> -	{ "bmg160" },
> -	{}
> +static const struct smi_node bsg1160_data = {
> +	.instances = {
> +		{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
> +		{ "bmc150_magn" },
> +		{ "bmg160" },
> +		{}
> +	},
> +	.bus_type = SMI_I2C,
>  };
>  
> -static const struct smi_instance bsg2150_data[]  = {
> -	{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
> -	{ "bmc150_magn" },
> -	/* The resources describe a 3th client, but it is not really there. */
> -	{ "bsg2150_dummy_dev" },
> -	{}
> +static const struct smi_node bsg2150_data = {
> +	.instances = {
> +		{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
> +		{ "bmc150_magn" },
> +		/* The resources describe a 3th client, but it is not really there. */
> +		{ "bsg2150_dummy_dev" },
> +		{}
> +	},
> +	.bus_type = SMI_I2C,
>  };
>  
> -static const struct smi_instance int3515_data[]  = {
> -	{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
> -	{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
> -	{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
> -	{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
> -	{}
> +static const struct smi_node int3515_data = {
> +	.instances = {
> +		{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
> +		{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
> +		{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
> +		{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
> +		{}
> +	},
> +	.bus_type = SMI_I2C,
>  };
>  
>  /*
> @@ -187,9 +313,9 @@ static const struct smi_instance int3515_data[]  = {
>   * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
>   */
>  static const struct acpi_device_id smi_acpi_ids[] = {
> -	{ "BSG1160", (unsigned long)bsg1160_data },
> -	{ "BSG2150", (unsigned long)bsg2150_data },
> -	{ "INT3515", (unsigned long)int3515_data },
> +	{ "BSG1160", (unsigned long)&bsg1160_data },
> +	{ "BSG2150", (unsigned long)&bsg2150_data },
> +	{ "INT3515", (unsigned long)&int3515_data },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(acpi, smi_acpi_ids);
>