[PATCH linux] Add BMC HWMON driver to kernel. Format patch based on Joel's comments.

Jeremy Kerr jk at ozlabs.org
Fri Nov 27 18:20:31 AEDT 2015


Hi Adam,

Thanks for v2. Some further comments:

> From: adamliyi <adamliyi at msn.com>
> 
> Signed-off-by: adamliyi <adamliyi at msn.com>

It'd be much better if you can use your actual name here.


> +config SENSORS_OCC
> +	tristate "BMC driver for OCC sensor"
> +	depends on I2C
> +	help
> +	  If you say yes here you get support for BMC to monitor IBM
> +	  Power CPU sensors via the On-Chip-Controller (OCC).
> +
> +	  This driver can aslo be built as a module. If so, the module
> +	  will be called occ.
> +

Quite minor, but can we use a more descriptive name here? Even i2c_occ
would be better. Or power8_occ? What other devices would this driver
support in future?

[We share this namespace with every other driver for every other
platform in the kernel, so specificity is good]


> +struct powr_sensor {
> +	uint16_t sensor_id;
> +	uint32_t update_tag;
> +	uint32_t accumulator;
> +	uint16_t value;
> +};

Minor nitpick: no need to abbreviate 'power' to 'powr'.

> +
> +struct caps_sensor {
> +	uint16_t curr_powercap;
> +	uint16_t curr_powerreading;
> +	uint16_t norm_powercap;
> +	uint16_t max_powercap;
> +	uint16_t min_powercap;
> +	uint16_t user_powerlimit;
> +};
> +
> +struct sensor_data_block {
> +	char sensor_type[5];
> +	uint8_t reserved0;
> +	uint8_t sensor_format;
> +	uint8_t sensor_length;
> +	uint8_t num_of_sensors;
> +	struct occ_sensor *sensor;
> +	struct powr_sensor *powr;
> +	struct caps_sensor *caps;
> +};
> +
> +struct occ_poll_data {
> +	uint8_t status;
> +	uint8_t ext_status;
> +	uint8_t occs_present;
> +	uint8_t config;
> +	uint8_t occ_state;
> +	uint8_t reserved0;
> +	uint8_t reserved1;
> +	uint8_t error_log_id;
> +	uint32_t error_log_addr_start;
> +	uint16_t error_log_length;
> +	uint8_t reserved2;
> +	uint8_t reserved3;
> +	char occ_version_string[17];
> +	char sensor_eye_catcher[7];
> +	uint8_t num_of_sensor_blocks;
> +	uint8_t sensor_data_version;
> +	struct sensor_data_block *blocks;
> +};
> +
> +struct occ_response {
> +	uint8_t sequence_num;
> +	uint8_t cmd_type;
> +	uint8_t rtn_status;
> +	uint16_t data_length;
> +	struct occ_poll_data data;
> +	uint16_t chk_sum;
> +	int temp_block_id;
> +	int freq_block_id;
> +	int power_block_id;
> +	int caps_block_id;
> +};
> +
> +/* data private to each client */
> +struct occ_drv_data {
> +	struct i2c_client	*client;
> +	struct device		*hwmon_dev;
> +	struct mutex		update_lock;
> +	bool			valid;
> +	unsigned long		last_updated;
> +	/* Minimum timer interval for sampling In jiffies */
> +	unsigned long		sample_time;
> +	struct occ_response	occ_resp;
> +};
> +
> +/* i2c read and write occ sensors */
> +
> +#define OCC_DATA_MAX 4096 /* 4KB at most */
> +#define I2C_STATUS_REG 0x000d0001
> +#define I2C_ERROR_REG  0x000d0002
> +#define I2C_READ_ERROR 1
> +#define I2C_WRITE_ERROR 2
> +#define I2C_DATABUFFER_SIZE_ERROR 3
> +
> +/* To generate attn to OCC */
> +#define ATTN_DATA                0x0006B035
> +
> +/* For BMC to read/write SRAM */
> +#define OCB_ADDRESS              0x0006B070
> +#define OCB_DATA                 0x0006B075
> +#define OCB_STATUS_CONTROL_AND   0x0006B072
> +#define OCB_STATUS_CONTROL_OR    0x0006B073
> +
> +#define OCC_COMMAND_ADDR 0xFFFF6000
> +#define OCC_RESPONSE_ADDR 0xFFFF7000
> +
> +static void deinit_occ_resp_buf(struct occ_response *p)
> +{
> +	int b;
> +
> +	if (!p)
> +		return;
> +
> +	if (!p->data.blocks)
> +		return;
> +
> +	for (b = 0; b < p->data.num_of_sensor_blocks; b++) {
> +		if (!p->data.blocks[b].sensor)
> +			kfree(p->data.blocks[b].sensor);
> +		if (!p->data.blocks[b].powr)
> +			kfree(p->data.blocks[b].powr);
> +		if (!p->data.blocks[b].caps)
> +			kfree(p->data.blocks[b].caps);
> +	}
> +
> +	kfree(p->data.blocks);
> +
> +	memset(p, 0, sizeof(*p));
> +}

I think it'd be better if you just allocated this once (possibly as part
of the struct occ_drv_data), rather than allocating and freeing the same
structure all the time.

> +
> +static ssize_t occ_i2c_read(struct i2c_client *client, char *buf, size_t count)
> +{
> +	int ret = 0;
> +
> +	if (count > OCC_DATA_MAX)
> +		count = OCC_DATA_MAX;
> +
> +	dev_dbg(&client->dev, "i2c_read: reading %zu bytes @0x%x.\n",
> +		count, client->addr);
> +	return i2c_master_recv(client, buf, count);
> +}
> +
> +static ssize_t occ_i2c_write(struct i2c_client *client, const char *buf,
> +				size_t count)
> +{
> +	int ret = 0;
> +
> +	if (count > OCC_DATA_MAX)
> +		count = OCC_DATA_MAX;
> +
> +	dev_dbg(&client->dev, "i2c_write: writing %zu bytes @0x%x.\n",
> +		count, client->addr);
> +	return i2c_master_send(client, buf, count);
> +}
> +
> +/* read two 4-byte value */
> +static int occ_getscom(struct i2c_client *client, uint32_t address,
> +			uint32_t *value0, uint32_t *value1)
> +{
> +	uint32_t ret = 0;
> +	char buf[8];
> +
> +	/* P8 i2c slave requires address to be shifted by 1 */
> +	address = address << 1;
> +
> +	ret = occ_i2c_write(client, (const char *)&address,
> +		sizeof(address));

If you use a const void * parameter on occ_i2c_write, you won't need all
this casting.

> +	/* FIXME: ast i2c driver does not read corret value
> +	 * if (ret != sizeof(address))
> +	 *	return -I2C_WRITE_ERROR;
> +	 */

Are you sure that's still the case? We should have fixed that in the i2c
driver already.


> +	ret = occ_i2c_read(client, buf, sizeof(buf));
> +	/* FIXME: ast i2c driver does not read corret value
> +	 * if (ret != sizeof(buf))
> +	 *	return -I2C_READ_ERROR;
> +	 */
> +	memcpy(value1, &buf[0], sizeof(*value1));
> +	memcpy(value0, &buf[4], sizeof(*value0));

Just use the correct type for these, and then use normal assignments:
	
        uint32_t data[2];

        ret = occ_i2c_read(client, data, sizeof(data));

        *value0 = data[0];
        *value1 = data[1];

Alternatively, can we just use a uint64_t here?

Also, best if we do the appropriate endian conversion too.

> +static int occ_putscom(struct i2c_client *client, uint32_t address,
> +		uint32_t data0, uint32_t data1)
> +{
> +	char buf[12];
> +	uint32_t ret = 0;
> +
> +	/* P8 i2c slave requires address to be shifted by 1 */
> +	address = address << 1;
> +
> +	memcpy(&buf[0], &address, sizeof(address));
> +	memcpy(&buf[4], &data1, sizeof(data1));
> +	memcpy(&buf[8],	&data0, sizeof(data0));

You've used magic numbers as array indices, but sizeofs() as the length
here. How about declaring buf as a u32[] instead, and use standard array
element assignment?

> +
> +	ret = occ_i2c_write(client, buf, sizeof(buf));
> +	/* FIXME: ast i2c driver does not read corret value
> +	 * if (ret != sizeof(buf))
> +	 *	return I2C_WRITE_ERROR;
> +	 */
> +	return 0;
> +}
> +
> +static inline uint16_t get_occdata_length(u8 *d)
> +{
> +	uint16_t data_length = 0;
> +
> +	data_length = d[3] << 8;
> +	data_length = data_length | d[4];
> +	return data_length;
> +}

just:

     return (d[3] << 8) | d[4];

Or even better, just use be16_to_cpup()

> +static int parse_occ_response(struct i2c_client *client,
> +		char *d, struct occ_response *o)
> +{
> +	int b = 0;
> +	int s = 0;
> +	int ret = 0;
> +	int dnum = 45;
> +	struct occ_sensor *f_sensor;
> +	struct occ_sensor *t_sensor;
> +	struct powr_sensor *p_sensor;
> +	struct caps_sensor *c_sensor;
> +
> +	o->sequence_num = d[0];
> +	o->cmd_type = d[1];
> +	o->rtn_status = d[2];
> +	o->data_length = d[3] << 8;
> +	o->data_length = o->data_length | d[4];

Isn't this the same as the function above?

> +	o->data.status = d[5];
> +	o->data.ext_status = d[6];
> +	o->data.occs_present = d[7];
> +	o->data.config = d[8];
> +	o->data.occ_state = d[9];
> +	o->data.reserved0 = d[10];
> +	o->data.reserved1 = d[11];
> +	o->data.error_log_id = d[12];
> +	o->data.error_log_addr_start = d[13] << 24;
> +	o->data.error_log_addr_start =
> +		o->data.error_log_addr_start | d[14] << 16;
> +	o->data.error_log_addr_start =
> +		o->data.error_log_addr_start | d[15] << 8;
> +	o->data.error_log_addr_start =
> +		o->data.error_log_addr_start | d[16];
> +	o->data.error_log_length = d[17] << 8;
> +	o->data.error_log_length = o->data.error_log_length | d[18];
> +	o->data.reserved2 = d[19];
> +	o->data.reserved3 = d[20];
> +	strncpy(o->data.occ_version_string, &d[21], 16);
> +	strncpy(&o->data.sensor_eye_catcher[0], &d[37], 6);
> +	o->data.sensor_eye_catcher[6] = '\0';
> +	o->data.num_of_sensor_blocks = d[43];
> +	o->data.sensor_data_version = d[44];

Wow. Isn't the layout of struct occ_response the same as the data in d?
If so, can't we just do a pointer assignment and read the members directly?


> +
> +	if (strcmp(o->data.sensor_eye_catcher, "SENSOR") != 0) {
> +		dev_err(&client->dev,
> +			"ERROR: SENSOR not found at byte 37 (%s)\n",
> +			o->data.sensor_eye_catcher);
> +		return -1;
> +	}
> +
> +	if (o->data.num_of_sensor_blocks == 0) {
> +		dev_err(&client->dev, "ERROR: SENSOR block num is 0\n");
> +		return -1;
> +	}
> +
> +	o->data.blocks = kzalloc(sizeof(struct sensor_data_block) *
> +				o->data.num_of_sensor_blocks, GFP_KERNEL);

kcalloc() might be better here.

> +	if (!o->data.blocks)
> +		return -ENOMEM;
> +
> +	dev_dbg(&client->dev, "Reading %d sensor blocks\n",
> +		o->data.num_of_sensor_blocks);
> +	o->temp_block_id = -1;
> +	o->freq_block_id = -1;
> +	o->power_block_id = -1;
> +	o->caps_block_id = -1;
> +	for (b = 0; b < o->data.num_of_sensor_blocks; b++) {
> +		/* 8-byte sensor block head */
> +		strncpy(&o->data.blocks[b].sensor_type[0],

No need to use an element reference, then deference. Just use:

                         o->data.blocks[b].sensor_type


> +			(const char *)&d[dnum], 4);
> +		o->data.blocks[b].reserved0 = d[dnum+4];
> +		o->data.blocks[b].sensor_format = d[dnum+5];
> +		o->data.blocks[b].sensor_length = d[dnum+6];
> +		o->data.blocks[b].num_of_sensors = d[dnum+7];
> +		dnum = dnum + 8;

More magic numbers. Can we just use a struct assignment for things like
this?

> +
> +		dev_dbg(&client->dev,
> +			"sensor block[%d]: type: %s, num_of_sensors: %d\n",
> +			b, o->data.blocks[b].sensor_type,
> +			o->data.blocks[b].num_of_sensors);
> +
> +		/* empty sensor block */
> +		if (o->data.blocks[b].num_of_sensors <= 0)
> +			continue;
> +		if (o->data.blocks[b].sensor_length == 0)
> +			continue;
> +
> +		if (strcmp(o->data.blocks[b].sensor_type, "FREQ") == 0) {
> +			o->data.blocks[b].sensor =
> +				kzalloc(sizeof(struct occ_sensor) *
> +					o->data.blocks[b].num_of_sensors,
> +					GFP_KERNEL);
> +
> +			if (!o->data.blocks[b].sensor) {
> +				ret = -ENOMEM;
> +				goto abort;
> +			}
> +			o->freq_block_id = b;
> +			for (s = 0; s < o->data.blocks[b].num_of_sensors; s++) {
> +				f_sensor = &o->data.blocks[b].sensor[s];
> +				f_sensor->sensor_id = (d[dnum]<<8) | d[dnum+1];
> +				f_sensor->value = (d[dnum+2]<<8) | d[dnum+3];
> +				dev_dbg(&client->dev,
> +					"sensor[%d]-[%d]: id: %u, value: %u\n",
> +					b, s, f_sensor->sensor_id,
> +					f_sensor->value);
> +				dnum = dnum + o->data.blocks[b].sensor_length;
> +			}
> +		} else if (strcmp(o->data.blocks[b].sensor_type, "TEMP") == 0) {
> +
> +			o->data.blocks[b].sensor =
> +				kzalloc(sizeof(struct occ_sensor) *
> +					o->data.blocks[b].num_of_sensors,
> +					GFP_KERNEL);
> +
> +			if (!o->data.blocks[b].sensor) {
> +				ret = -ENOMEM;
> +				goto abort;
> +			}
> +
> +			o->temp_block_id = b;
> +			for (s = 0; s < o->data.blocks[b].num_of_sensors; s++) {
> +				t_sensor = &o->data.blocks[b].sensor[s];
> +				t_sensor->sensor_id = (d[dnum]<<8) | d[dnum+1];
> +				t_sensor->value = (d[dnum+2] << 8) | d[dnum+3];
> +				dev_dbg(&client->dev,
> +					"sensor[%d]-[%d]: id: %u, value: %u\n",
> +					b, s, t_sensor->sensor_id,
> +					t_sensor->value);
> +				dnum = dnum + o->data.blocks[b].sensor_length;
> +			}
> +		} else if (strcmp(o->data.blocks[b].sensor_type, "POWR") == 0) {
> +
> +			o->data.blocks[b].powr =
> +				kzalloc(sizeof(struct powr_sensor) *
> +					o->data.blocks[b].num_of_sensors,
> +					GFP_KERNEL);
> +
> +			if (!o->data.blocks[b].powr) {
> +				ret = -ENOMEM;
> +				goto abort;
> +			}
> +			o->power_block_id = b;
> +			for (s = 0; s < o->data.blocks[b].num_of_sensors; s++) {
> +				p_sensor = &o->data.blocks[b].powr[s];
> +				p_sensor->sensor_id = (d[dnum]<<8) | d[dnum+1];
> +				p_sensor->update_tag =
> +					(d[dnum+2] << 24) | (d[dnum+3] << 16) |
> +					(d[dnum+4] << 8) | d[dnum+5];
> +				p_sensor->accumulator =
> +					(d[dnum+6] << 24) | (d[dnum+7] << 16) |
> +					(d[dnum+8] << 8) | d[dnum+9];
> +				p_sensor->value =
> +					(d[dnum+10] << 8) | d[dnum+11];
> +
> +				dev_dbg(&client->dev,
> +					"sensor[%d]-[%d]: id: %u, value: %u\n",
> +					b, s, p_sensor->sensor_id,
> +					p_sensor->value);
> +
> +				dnum = dnum + o->data.blocks[b].sensor_length;
> +			}
> +		} else if (strcmp(o->data.blocks[b].sensor_type, "CAPS") == 0) {
> +
> +			o->data.blocks[b].caps =
> +				kzalloc(sizeof(struct caps_sensor) *
> +					o->data.blocks[b].num_of_sensors,
> +					GFP_KERNEL);
> +
> +			if (!o->data.blocks[b].caps) {
> +				ret = -ENOMEM;
> +				goto abort;
> +			}
> +			o->caps_block_id = b;
> +			for (s = 0; s < o->data.blocks[b].num_of_sensors; s++) {
> +				c_sensor = &o->data.blocks[b].caps[s];
> +				c_sensor->curr_powercap =
> +					(d[dnum] << 8) | d[dnum+1];
> +				c_sensor->curr_powerreading =
> +					(d[dnum+2] << 8) | d[dnum+3];
> +				c_sensor->norm_powercap =
> +					(d[dnum+4] << 8) | d[dnum+5];
> +				c_sensor->max_powercap =
> +					(d[dnum+6] << 8) | d[dnum+7];
> +				c_sensor->min_powercap =
> +					(d[dnum+8] << 8) | d[dnum+9];
> +				c_sensor->user_powerlimit =
> +					(d[dnum+10] << 8) | d[dnum+11];
> +
> +				dnum = dnum + o->data.blocks[b].sensor_length;
> +				dev_dbg(&client->dev, "CAPS sensor #%d:\n", s);
> +				dev_dbg(&client->dev, "curr_powercap is %x\n",
> +					c_sensor->curr_powercap);
> +				dev_dbg(&client->dev,
> +					"curr_powerreading is %x\n",
> +					c_sensor->curr_powerreading);
> +				dev_dbg(&client->dev, "norm_powercap is %x\n",
> +					c_sensor->norm_powercap);
> +				dev_dbg(&client->dev, "max_powercap is %x\n",
> +					c_sensor->max_powercap);
> +				dev_dbg(&client->dev, "min_powercap is %x\n",
> +					c_sensor->min_powercap);
> +				dev_dbg(&client->dev, "user_powerlimit is %x\n",
> +					c_sensor->user_powerlimit);
> +			}
> +
> +		} else {
> +			dev_err(&client->dev,
> +				"ERROR: sensor type %s not supported\n",
> +				o->data.blocks[b].sensor_type);
> +			ret = -1;
> +			goto abort;
> +		}
> +	}
> +
> +	return 0;
> +abort:
> +	deinit_occ_resp_buf(o);
> +	return ret;
> +}
> +
> +static int occ_get_all(struct i2c_client *client, struct occ_response *occ_resp)
> +{
> +	char occ_data[OCC_DATA_MAX];
> +	uint16_t num_bytes = 0;
> +	int b = 0;
> +	int ret = 0;
> +
> +	/* Init OCB */
> +	occ_putscom(client, OCB_STATUS_CONTROL_OR,  0x08000000, 0x00000000);
> +	occ_putscom(client, OCB_STATUS_CONTROL_AND, 0xFBFFFFFF, 0xFFFFFFFF);
> +
> +	/* Send poll command to OCC */
> +	occ_putscom(client, OCB_ADDRESS, OCC_COMMAND_ADDR, 0x00000000);
> +	occ_putscom(client, OCB_ADDRESS, OCC_COMMAND_ADDR, 0x00000000);
> +	occ_putscom(client, OCB_DATA, 0x00000001, 0x10001100);
> +
> +	/* Trigger ATTN */
> +	occ_putscom(client, ATTN_DATA, 0x01010000, 0x00000000);
> +
> +	/* Get response data */
> +	occ_putscom(client, OCB_ADDRESS, OCC_RESPONSE_ADDR, 0x00000000);
> +	occ_getscomb(client, OCB_DATA, occ_data, 0);
> +
> +	num_bytes = get_occdata_length(occ_data);
> +
> +	dev_dbg(&client->dev, "OCC data length: %d\n", num_bytes);
> +
> +	if (num_bytes > OCC_DATA_MAX) {
> +		dev_err(&client->dev, "ERROR: OCC data length must be < 4KB\n");
> +		return -1;
> +	}
> +
> +	if (num_bytes <= 0) {
> +		dev_err(&client->dev, "ERROR: OCC data length is zero\n");
> +		return -1;
> +	}
> +
> +	for (b = 8; b < num_bytes + 8; b = b + 8)
> +		occ_getscomb(client, OCB_DATA, occ_data, b);
> +
> +	ret = parse_occ_response(client, occ_data, occ_resp);
> +
> +	return ret;
> +}
> +
> +
> +static int occ_update_device(struct device *dev)
> +{
> +	struct occ_drv_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
> +	int ret = 0;
> +
> +	mutex_lock(&data->update_lock);
> +
> +	if (time_after(jiffies, data->last_updated + data->sample_time)
> +	    || !data->valid) {
> +		deinit_occ_resp_buf(&data->occ_resp);
> +
> +		ret = occ_get_all(client, &data->occ_resp);
> +
> +		data->last_updated = jiffies;
> +		data->valid = 1;
> +	}
> +	mutex_unlock(&data->update_lock);
> +
> +	return ret;
> +}
> +
> +/* sysfs attributes for hwmon */
> +
> +static ssize_t show_occ_temp_input(struct device *hwmon_dev,
> +		struct device_attribute *da, char *buf)
> +{
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
> +	int n = attr->index;
> +	struct device *dev = hwmon_dev->parent;
> +	struct occ_drv_data *data = dev_get_drvdata(dev);
> +	int ret = 0;

No need to initialise things like this, this just prevents valid 'use of
uninitialised variable' warnings.

> +	struct occ_sensor *sensor;
> +	int val = 0;
> +
> +	ret = occ_update_device(dev);
> +
> +	if (ret != 0) {
> +		dev_err(dev, "ERROR: cannot get occ sensor data: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (!data->occ_resp.data.blocks)
> +		return -1;
> +
> +	sensor =
> +		data->occ_resp.data.blocks[data->occ_resp.temp_block_id].sensor;
> +
> +	if (!sensor)
> +		return -1;
> +
> +	/* in millidegree Celsius */
> +	val = sensor[n - 1].value * 1000;
> +
> +	return sprintf(buf, "%d\n", val);
> +}

You have a lot of duplicated code in these show_ functions, can you
abstract the common parts into a helper?

> +static struct sensor_device_attribute temp_input[] = {
> +	SENSOR_ATTR(temp1_input, S_IRUGO, show_occ_temp_input, NULL, 1),
> +	SENSOR_ATTR(temp2_input, S_IRUGO, show_occ_temp_input, NULL, 2),
> +	SENSOR_ATTR(temp3_input, S_IRUGO, show_occ_temp_input, NULL, 3),
> +	SENSOR_ATTR(temp4_input, S_IRUGO, show_occ_temp_input, NULL, 4),
> +	SENSOR_ATTR(temp5_input, S_IRUGO, show_occ_temp_input, NULL, 5),
> +	SENSOR_ATTR(temp6_input, S_IRUGO, show_occ_temp_input, NULL, 6),
> +	SENSOR_ATTR(temp7_input, S_IRUGO, show_occ_temp_input, NULL, 7),
> +	SENSOR_ATTR(temp8_input, S_IRUGO, show_occ_temp_input, NULL, 8),
> +	SENSOR_ATTR(temp9_input, S_IRUGO, show_occ_temp_input, NULL, 9),
> +	SENSOR_ATTR(temp10_input, S_IRUGO, show_occ_temp_input, NULL, 10),
> +	SENSOR_ATTR(temp11_input, S_IRUGO, show_occ_temp_input, NULL, 11),
> +	SENSOR_ATTR(temp12_input, S_IRUGO, show_occ_temp_input, NULL, 12),
> +	SENSOR_ATTR(temp13_input, S_IRUGO, show_occ_temp_input, NULL, 13),
> +	SENSOR_ATTR(temp14_input, S_IRUGO, show_occ_temp_input, NULL, 14),
> +	SENSOR_ATTR(temp15_input, S_IRUGO, show_occ_temp_input, NULL, 15),
> +	SENSOR_ATTR(temp16_input, S_IRUGO, show_occ_temp_input, NULL, 16),
> +	SENSOR_ATTR(temp17_input, S_IRUGO, show_occ_temp_input, NULL, 17),
> +	SENSOR_ATTR(temp18_input, S_IRUGO, show_occ_temp_input, NULL, 18),
> +	SENSOR_ATTR(temp19_input, S_IRUGO, show_occ_temp_input, NULL, 19),
> +	SENSOR_ATTR(temp20_input, S_IRUGO, show_occ_temp_input, NULL, 20),
> +	SENSOR_ATTR(temp21_input, S_IRUGO, show_occ_temp_input, NULL, 21),
> +	SENSOR_ATTR(temp22_input, S_IRUGO, show_occ_temp_input, NULL, 22),
> +};
> +
> +static struct sensor_device_attribute temp_label[] = {
> +	SENSOR_ATTR(temp1_label, S_IRUGO, show_occ_temp_label, NULL, 1),
> +	SENSOR_ATTR(temp2_label, S_IRUGO, show_occ_temp_label, NULL, 2),
> +	SENSOR_ATTR(temp3_label, S_IRUGO, show_occ_temp_label, NULL, 3),
> +	SENSOR_ATTR(temp4_label, S_IRUGO, show_occ_temp_label, NULL, 4),
> +	SENSOR_ATTR(temp5_label, S_IRUGO, show_occ_temp_label, NULL, 5),
> +	SENSOR_ATTR(temp6_label, S_IRUGO, show_occ_temp_label, NULL, 6),
> +	SENSOR_ATTR(temp7_label, S_IRUGO, show_occ_temp_label, NULL, 7),
> +	SENSOR_ATTR(temp8_label, S_IRUGO, show_occ_temp_label, NULL, 8),
> +	SENSOR_ATTR(temp9_label, S_IRUGO, show_occ_temp_label, NULL, 9),
> +	SENSOR_ATTR(temp10_label, S_IRUGO, show_occ_temp_label, NULL, 10),
> +	SENSOR_ATTR(temp11_label, S_IRUGO, show_occ_temp_label, NULL, 11),
> +	SENSOR_ATTR(temp12_label, S_IRUGO, show_occ_temp_label, NULL, 12),
> +	SENSOR_ATTR(temp13_label, S_IRUGO, show_occ_temp_label, NULL, 13),
> +	SENSOR_ATTR(temp14_label, S_IRUGO, show_occ_temp_label, NULL, 14),
> +	SENSOR_ATTR(temp15_label, S_IRUGO, show_occ_temp_label, NULL, 15),
> +	SENSOR_ATTR(temp16_label, S_IRUGO, show_occ_temp_label, NULL, 16),
> +	SENSOR_ATTR(temp17_label, S_IRUGO, show_occ_temp_label, NULL, 17),
> +	SENSOR_ATTR(temp18_label, S_IRUGO, show_occ_temp_label, NULL, 18),
> +	SENSOR_ATTR(temp19_label, S_IRUGO, show_occ_temp_label, NULL, 19),
> +	SENSOR_ATTR(temp20_label, S_IRUGO, show_occ_temp_label, NULL, 20),
> +	SENSOR_ATTR(temp21_label, S_IRUGO, show_occ_temp_label, NULL, 21),
> +	SENSOR_ATTR(temp22_label, S_IRUGO, show_occ_temp_label, NULL, 22),
> +
> +};
> +
> +#define TEMP_UNIT_ATTRS(X)                      \
> +{	&temp_input[X].dev_attr.attr,           \
> +	&temp_label[X].dev_attr.attr,          \
> +	NULL                                    \
> +}
> +
> +/* 10-core CPU, occ has 22 temp sensors, more socket, more sensors */
> +static struct attribute *occ_temp_attr[][3] = {
> +	TEMP_UNIT_ATTRS(0),
> +	TEMP_UNIT_ATTRS(1),
> +	TEMP_UNIT_ATTRS(2),
> +	TEMP_UNIT_ATTRS(3),
> +	TEMP_UNIT_ATTRS(4),
> +	TEMP_UNIT_ATTRS(5),
> +	TEMP_UNIT_ATTRS(6),
> +	TEMP_UNIT_ATTRS(7),
> +	TEMP_UNIT_ATTRS(8),
> +	TEMP_UNIT_ATTRS(9),
> +	TEMP_UNIT_ATTRS(10),
> +	TEMP_UNIT_ATTRS(11),
> +	TEMP_UNIT_ATTRS(12),
> +	TEMP_UNIT_ATTRS(13),
> +	TEMP_UNIT_ATTRS(14),
> +	TEMP_UNIT_ATTRS(15),
> +	TEMP_UNIT_ATTRS(16),
> +	TEMP_UNIT_ATTRS(17),
> +	TEMP_UNIT_ATTRS(18),
> +	TEMP_UNIT_ATTRS(19),
> +	TEMP_UNIT_ATTRS(20),
> +	TEMP_UNIT_ATTRS(21),
> +};
> +
> +static const struct attribute_group occ_temp_attr_group[] = {
> +	{ .attrs = occ_temp_attr[0] },
> +	{ .attrs = occ_temp_attr[1] },
> +	{ .attrs = occ_temp_attr[2] },
> +	{ .attrs = occ_temp_attr[3] },
> +	{ .attrs = occ_temp_attr[4] },
> +	{ .attrs = occ_temp_attr[5] },
> +	{ .attrs = occ_temp_attr[6] },
> +	{ .attrs = occ_temp_attr[7] },
> +	{ .attrs = occ_temp_attr[8] },
> +	{ .attrs = occ_temp_attr[9] },
> +	{ .attrs = occ_temp_attr[10] },
> +	{ .attrs = occ_temp_attr[11] },
> +	{ .attrs = occ_temp_attr[12] },
> +	{ .attrs = occ_temp_attr[13] },
> +	{ .attrs = occ_temp_attr[14] },
> +	{ .attrs = occ_temp_attr[15] },
> +	{ .attrs = occ_temp_attr[16] },
> +	{ .attrs = occ_temp_attr[17] },
> +	{ .attrs = occ_temp_attr[18] },
> +	{ .attrs = occ_temp_attr[19] },
> +	{ .attrs = occ_temp_attr[20] },
> +	{ .attrs = occ_temp_attr[21] },
> +};
> +
> +
> +static struct sensor_device_attribute freq_input[] = {
> +	SENSOR_ATTR(freq1_input, S_IRUGO, show_occ_freq_input, NULL, 1),
> +	SENSOR_ATTR(freq2_input, S_IRUGO, show_occ_freq_input, NULL, 2),
> +	SENSOR_ATTR(freq3_input, S_IRUGO, show_occ_freq_input, NULL, 3),
> +	SENSOR_ATTR(freq4_input, S_IRUGO, show_occ_freq_input, NULL, 4),
> +	SENSOR_ATTR(freq5_input, S_IRUGO, show_occ_freq_input, NULL, 5),
> +	SENSOR_ATTR(freq6_input, S_IRUGO, show_occ_freq_input, NULL, 6),
> +	SENSOR_ATTR(freq7_input, S_IRUGO, show_occ_freq_input, NULL, 7),
> +	SENSOR_ATTR(freq8_input, S_IRUGO, show_occ_freq_input, NULL, 8),
> +	SENSOR_ATTR(freq9_input, S_IRUGO, show_occ_freq_input, NULL, 9),
> +	SENSOR_ATTR(freq10_input, S_IRUGO, show_occ_freq_input, NULL, 10),
> +};
> +
> +static struct sensor_device_attribute freq_label[] = {
> +	SENSOR_ATTR(freq1_label, S_IRUGO, show_occ_freq_label, NULL, 1),
> +	SENSOR_ATTR(freq2_label, S_IRUGO, show_occ_freq_label, NULL, 2),
> +	SENSOR_ATTR(freq3_label, S_IRUGO, show_occ_freq_label, NULL, 3),
> +	SENSOR_ATTR(freq4_label, S_IRUGO, show_occ_freq_label, NULL, 4),
> +	SENSOR_ATTR(freq5_label, S_IRUGO, show_occ_freq_label, NULL, 5),
> +	SENSOR_ATTR(freq6_label, S_IRUGO, show_occ_freq_label, NULL, 6),
> +	SENSOR_ATTR(freq7_label, S_IRUGO, show_occ_freq_label, NULL, 7),
> +	SENSOR_ATTR(freq8_label, S_IRUGO, show_occ_freq_label, NULL, 8),
> +	SENSOR_ATTR(freq9_label, S_IRUGO, show_occ_freq_label, NULL, 9),
> +	SENSOR_ATTR(freq10_label, S_IRUGO, show_occ_freq_label, NULL, 10),
> +
> +};
> +
> +#define FREQ_UNIT_ATTRS(X)                      \
> +{	&freq_input[X].dev_attr.attr,           \
> +	&freq_label[X].dev_attr.attr,          \
> +	NULL                                    \
> +}
> +
> +/* 10-core CPU, occ has 22 freq sensors, more socket, more sensors */
> +static struct attribute *occ_freq_attr[][3] = {
> +	FREQ_UNIT_ATTRS(0),
> +	FREQ_UNIT_ATTRS(1),
> +	FREQ_UNIT_ATTRS(2),
> +	FREQ_UNIT_ATTRS(3),
> +	FREQ_UNIT_ATTRS(4),
> +	FREQ_UNIT_ATTRS(5),
> +	FREQ_UNIT_ATTRS(6),
> +	FREQ_UNIT_ATTRS(7),
> +	FREQ_UNIT_ATTRS(8),
> +	FREQ_UNIT_ATTRS(9),
> +};
> +
> +static const struct attribute_group occ_freq_attr_group[] = {
> +	{ .attrs = occ_freq_attr[0] },
> +	{ .attrs = occ_freq_attr[1] },
> +	{ .attrs = occ_freq_attr[2] },
> +	{ .attrs = occ_freq_attr[3] },
> +	{ .attrs = occ_freq_attr[4] },
> +	{ .attrs = occ_freq_attr[5] },
> +	{ .attrs = occ_freq_attr[6] },
> +	{ .attrs = occ_freq_attr[7] },
> +	{ .attrs = occ_freq_attr[8] },
> +	{ .attrs = occ_freq_attr[9] },
> +};
> +
> +static struct sensor_device_attribute_2 caps_curr_powercap[] = {
> +	SENSOR_ATTR_2(caps_curr_powercap, S_IRUGO, show_occ_caps, NULL, 0, 1),
> +};
> +static struct sensor_device_attribute_2 caps_curr_powerreading[] = {
> +	SENSOR_ATTR_2(caps_curr_powerreading, S_IRUGO,
> +		show_occ_caps, NULL, 1, 1),
> +};
> +static struct sensor_device_attribute_2 caps_norm_powercap[] = {
> +	SENSOR_ATTR_2(caps_norm_powercap, S_IRUGO, show_occ_caps,
> +		NULL, 2, 1),
> +};
> +static struct sensor_device_attribute_2 caps_max_powercap[] = {
> +	SENSOR_ATTR_2(caps_max_powercap, S_IRUGO, show_occ_caps, NULL, 3, 1),
> +};
> +static struct sensor_device_attribute_2 caps_min_powercap[] = {
> +	SENSOR_ATTR_2(caps_min_powercap, S_IRUGO, show_occ_caps, NULL, 4, 1),
> +};
> +static struct sensor_device_attribute_2 caps_user_powerlimit[] = {
> +	SENSOR_ATTR_2(caps_user_powerlimit, S_IRUGO, show_occ_caps, NULL, 5, 1),
> +};
> +#define CAPS_UNIT_ATTRS(X)                      \
> +{	&caps_curr_powercap[X].dev_attr.attr,           \
> +	&caps_curr_powerreading[X].dev_attr.attr,           \
> +	&caps_norm_powercap[X].dev_attr.attr,           \
> +	&caps_max_powercap[X].dev_attr.attr,           \
> +	&caps_min_powercap[X].dev_attr.attr,           \
> +	&caps_user_powerlimit[X].dev_attr.attr,           \
> +	NULL                                    \
> +}
> +
> +/* 10-core CPU, occ has 1 caps sensors */
> +static struct attribute *occ_caps_attr[][7] = {
> +	CAPS_UNIT_ATTRS(0),
> +};
> +static const struct attribute_group occ_caps_attr_group[] = {
> +	{ .attrs = occ_caps_attr[0] },
> +};
> +
> +static struct sensor_device_attribute power_input[] = {
> +	SENSOR_ATTR(power1_input, S_IRUGO, show_occ_power_input, NULL, 1),
> +	SENSOR_ATTR(power2_input, S_IRUGO, show_occ_power_input, NULL, 2),
> +	SENSOR_ATTR(power3_input, S_IRUGO, show_occ_power_input, NULL, 3),
> +	SENSOR_ATTR(power4_input, S_IRUGO, show_occ_power_input, NULL, 4),
> +	SENSOR_ATTR(power5_input, S_IRUGO, show_occ_power_input, NULL, 5),
> +	SENSOR_ATTR(power6_input, S_IRUGO, show_occ_power_input, NULL, 6),
> +	SENSOR_ATTR(power7_input, S_IRUGO, show_occ_power_input, NULL, 7),
> +	SENSOR_ATTR(power8_input, S_IRUGO, show_occ_power_input, NULL, 8),
> +	SENSOR_ATTR(power9_input, S_IRUGO, show_occ_power_input, NULL, 9),
> +	SENSOR_ATTR(power10_input, S_IRUGO, show_occ_power_input, NULL, 10),
> +	SENSOR_ATTR(power11_input, S_IRUGO, show_occ_power_input, NULL, 11),
> +};
> +
> +static struct sensor_device_attribute power_label[] = {
> +	SENSOR_ATTR(power1_label, S_IRUGO, show_occ_power_label, NULL, 1),
> +	SENSOR_ATTR(power2_label, S_IRUGO, show_occ_power_label, NULL, 2),
> +	SENSOR_ATTR(power3_label, S_IRUGO, show_occ_power_label, NULL, 3),
> +	SENSOR_ATTR(power4_label, S_IRUGO, show_occ_power_label, NULL, 4),
> +	SENSOR_ATTR(power5_label, S_IRUGO, show_occ_power_label, NULL, 5),
> +	SENSOR_ATTR(power6_label, S_IRUGO, show_occ_power_label, NULL, 6),
> +	SENSOR_ATTR(power7_label, S_IRUGO, show_occ_power_label, NULL, 7),
> +	SENSOR_ATTR(power8_label, S_IRUGO, show_occ_power_label, NULL, 8),
> +	SENSOR_ATTR(power9_label, S_IRUGO, show_occ_power_label, NULL, 9),
> +	SENSOR_ATTR(power10_label, S_IRUGO, show_occ_power_label, NULL, 10),
> +	SENSOR_ATTR(power11_label, S_IRUGO, show_occ_power_label, NULL, 11),
> +};
> +
> +#define POWER_UNIT_ATTRS(X)                      \
> +{	&power_input[X].dev_attr.attr,           \
> +	&power_label[X].dev_attr.attr,          \
> +	NULL                                    \
> +}
> +
> +/* 10-core CPU, occ has 11 power sensors, more socket, more sensors */
> +static struct attribute *occ_power_attr[][3] = {
> +	POWER_UNIT_ATTRS(0),
> +	POWER_UNIT_ATTRS(1),
> +	POWER_UNIT_ATTRS(2),
> +	POWER_UNIT_ATTRS(3),
> +	POWER_UNIT_ATTRS(4),
> +	POWER_UNIT_ATTRS(5),
> +	POWER_UNIT_ATTRS(6),
> +	POWER_UNIT_ATTRS(7),
> +	POWER_UNIT_ATTRS(8),
> +	POWER_UNIT_ATTRS(9),
> +	POWER_UNIT_ATTRS(10),
> +};
> +
> +static const struct attribute_group occ_power_attr_group[] = {
> +	{ .attrs = occ_power_attr[0] },
> +	{ .attrs = occ_power_attr[1] },
> +	{ .attrs = occ_power_attr[2] },
> +	{ .attrs = occ_power_attr[3] },
> +	{ .attrs = occ_power_attr[4] },
> +	{ .attrs = occ_power_attr[5] },
> +	{ .attrs = occ_power_attr[6] },
> +	{ .attrs = occ_power_attr[7] },
> +	{ .attrs = occ_power_attr[8] },
> +	{ .attrs = occ_power_attr[9] },
> +	{ .attrs = occ_power_attr[10] },
> +};

There's a lot of stuff repeated 10 times here. Can we not generate this
device info at runtime instead? Do we need flexibility for different
numbers of sensors? Should we be encoding this in the device tree node?

> +
> +static void occ_remove_sysfs_files(struct device *dev)
> +{
> +	int i = 0;
> +
> +	for (i = 0; i < ARRAY_SIZE(occ_temp_attr_group); i++)
> +		sysfs_remove_group(&dev->kobj, &occ_temp_attr_group[i]);
> +
> +	for (i = 0; i < ARRAY_SIZE(occ_freq_attr_group); i++)
> +		sysfs_remove_group(&dev->kobj, &occ_freq_attr_group[i]);
> +
> +	for (i = 0; i < ARRAY_SIZE(occ_power_attr_group); i++)
> +		sysfs_remove_group(&dev->kobj, &occ_power_attr_group[i]);
> +
> +	for (i = 0; i < ARRAY_SIZE(occ_caps_attr_group); i++)
> +		sysfs_remove_group(&dev->kobj, &occ_caps_attr_group[i]);
> +}
> +
> +
> +static int occ_create_sysfs_attribute(struct device *dev)
> +{
> +	/* The sensor number varies for different
> +	 * platform depending on core number. We'd better
> +	 * create them dynamically
> +	 */
> +	struct occ_drv_data *drv_data = dev_get_drvdata(dev);

You seem to be passing the struct device around a lot, and then doing
dev_get_drvdata. Just pass your own struct instead.

> +	int i = 0;
> +	int num_of_sensors = 0;
> +	int ret = 0;
> +	struct occ_response *rsp = NULL;
> +
> +	/* get sensor number from occ. */
> +	ret = occ_update_device(dev);
> +	if (ret != 0) {
> +		dev_err(dev, "ERROR: cannot get occ sensor data: %d\n", ret);
> +		return ret;
> +	}
> +
> +	rsp = &drv_data->occ_resp;
> +	if (!rsp->data.blocks)
> +		return -1;
> +
> +	/* temp sensors */
> +	if (rsp->temp_block_id >= 0) {
> +		num_of_sensors =
> +			rsp->data.blocks[rsp->temp_block_id].num_of_sensors;
> +		for (i = 0; i < num_of_sensors; i++) {
> +			ret = sysfs_create_group(&drv_data->hwmon_dev->kobj,
> +				&occ_temp_attr_group[i]);
> +			if (ret) {
> +				dev_err(dev, "error create temp sysfs entry\n");
> +				goto error;
> +			}
> +		}
> +	}
> +
> +	/* freq sensors */
> +	if (rsp->freq_block_id >= 0) {
> +		num_of_sensors =
> +			rsp->data.blocks[rsp->freq_block_id].num_of_sensors;
> +		for (i = 0; i < num_of_sensors; i++) {
> +			ret = sysfs_create_group(&drv_data->hwmon_dev->kobj,
> +				&occ_freq_attr_group[i]);
> +			if (ret) {
> +				dev_err(dev, "error create freq sysfs entry\n");
> +				goto error;
> +			}
> +		}
> +	}
> +
> +	/* power sensors */
> +	dev_dbg(dev, "power_block_id: %d\n", rsp->power_block_id);
> +	if (rsp->power_block_id >= 0) {
> +		num_of_sensors =
> +			rsp->data.blocks[rsp->power_block_id].num_of_sensors;
> +		for (i = 0; i < num_of_sensors; i++) {
> +			ret = sysfs_create_group(&drv_data->hwmon_dev->kobj,
> +				&occ_power_attr_group[i]);
> +			if (ret) {
> +				dev_err(dev, "error create power sysfs entry\n");
> +				goto error;
> +			}
> +		}
> +	}
> +
> +	/* caps sensors */
> +	dev_dbg(dev, "caps_block_id: %d\n", rsp->caps_block_id);
> +	if (rsp->caps_block_id >= 0) {
> +		num_of_sensors =
> +			rsp->data.blocks[rsp->caps_block_id].num_of_sensors;
> +		for (i = 0; i < num_of_sensors; i++) {
> +			ret = sysfs_create_group(&drv_data->hwmon_dev->kobj,
> +				&occ_caps_attr_group[i]);
> +			if (ret) {
> +				dev_err(dev, "error create caps sysfs entry\n");
> +				goto error;
> +			}
> +		}
> +	}
> +
> +	return 0;
> +error:
> +	occ_remove_sysfs_files(drv_data->hwmon_dev);
> +	return ret;
> +}
> +
> +/* device probe and removal */
> +
> +#define OCC_I2C_ADDR 0x50
> +#define OCC_I2C_NAME "occ-i2c"
> +
> +enum occ_type {
> +	occ_id,
> +};
> +
> +static int occ_probe(struct i2c_client *client, const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct occ_drv_data *data;
> +	unsigned long funcs;
> +	struct device_node *np = dev->of_node;
> +	int ret = 0;
> +
> +	data = devm_kzalloc(dev, sizeof(struct occ_drv_data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->client = client;
> +	i2c_set_clientdata(client, data);
> +	mutex_init(&data->update_lock);
> +	data->sample_time = HZ;
> +
> +	/* We have several ways to get client address:
> +	 * 1. i2c_board_info
> +	 * 2. device table
> +	 * 3. user space sysfs new_device interface.
> +	 * Here we use the 3rd method
> +	 */

That's not really correct - the method you use will depend on how the
device was probed.

> +
> +	/* Read address from device table. The address is supposed to be
> +	 * assigned by i2c-core using the address_list, but that does not work.
> +	 * Have to read from DT explicilty
> +	 */
> +
> +	/*
> +	 * if (of_property_read_u32(np, "reg", &pval)) {
> +	 *	dev_err(&client->dev, "invalid reg\n");
> +	 * }
> +	 * client->addr = pval;
> +	 */

You will never need that code; the address assignment will aready be
done for you.

> +
> +	/* configure the driver */
> +	dev_dbg(dev, "occ register hwmon @0x%x\n", client->addr);
> +
> +	/* create sysfs attributes based on sensor number read from OCC */
> +	data->hwmon_dev = hwmon_device_register(dev);
> +	if (IS_ERR(data->hwmon_dev))
> +		return PTR_ERR(data->hwmon_dev);
> +
> +	ret = occ_create_sysfs_attribute(dev);
> +	if (ret) {
> +		hwmon_device_unregister(data->hwmon_dev);
> +		return ret;
> +	}
> +
> +	data->hwmon_dev->parent = dev;
> +
> +	dev_dbg(dev, "%s: sensor '%s'\n",
> +		 dev_name(data->hwmon_dev), client->name);
> +
> +	funcs = i2c_get_functionality(client->adapter);
> +	dev_dbg(dev, "i2c adaptor supports function: 0x%lx\n", funcs);

That's not really needed, this can be queried separately.

> +/* used by old-style board info. */
> +static const struct i2c_device_id occ_ids[] = {
> +	{ OCC_I2C_NAME, occ_id, },
> +	{ /* LIST END */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, occ_ids);

We should just rely on the DT instead of this.

> +
> +/* use by device table */
> +static const struct of_device_id i2c_occ_of_match[] = {
> +	{.compatible = "ibm,occ-i2c"},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, i2c_occ_of_match);
> +
> +#ifdef CONFIG_PM
> +static int occ_suspend(struct device *dev)
> +{
> +	/* TODO */
> +	return 0;
> +}
> +
> +static int occ_resume(struct device *dev)
> +{
> +	/* TODO */
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops occ_dev_pm_ops = {
> +	.suspend	= occ_suspend,
> +	.resume		= occ_resume,
> +};
> +#define OCC_DEV_PM_OPS (&occ_dev_pm_ops)
> +#else
> +#define OCC_DEV_PM_OPS NULL
> +#endif /* CONFIG_PM */

I don't think we'll need to support suspend/resume on these devices.

> +
> +/* i2c-core uses i2c-detect() to detect device in bellow address list.
> + *  If exists, address will be assigned to client.
> + * It is also possible to read address from device table.
> + */
> +static const unsigned short normal_i2c[] = {0x50, 0x51, I2C_CLIENT_END };
> +
> +/* Return 0 if detection is successful, -ENODEV otherwise */
> +static int occ_detect(struct i2c_client *new_client,
> +		       struct i2c_board_info *info)
> +{
> +	/* i2c-core needs this function to instantiate new device */
> +	strncpy(info->type, OCC_I2C_NAME, sizeof(OCC_I2C_NAME));
> +	return 0;
> +}

No need for this, we can use use the of_match_table here.

Regards,


Jeremy


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