diff options
Diffstat (limited to 'drivers/iio/light')
| -rw-r--r-- | drivers/iio/light/cm32181.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c index a5deb0750313..6594251ce5ca 100644 --- a/drivers/iio/light/cm32181.c +++ b/drivers/iio/light/cm32181.c @@ -4,6 +4,7 @@ * Author: Kevin Tsai <ktsai@capellamicro.com> */ +#include <linux/acpi.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/i2c.h> @@ -54,6 +55,15 @@ #define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c +/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */ +#define CPM0_REGS_BITMAP 2 +#define CPM0_HEADER_SIZE 3 + +/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */ +#define CPM1_LUX_PER_BIT 0 +#define CPM1_CALIBSCALE 1 +#define CPM1_SIZE 3 + /* CM3218 Family */ static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 }; static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 }; @@ -66,6 +76,7 @@ static const int cm32181_als_it_values[] = { struct cm32181_chip { struct i2c_client *client; + struct device *dev; struct mutex lock; u16 conf_regs[CM32181_CONF_REG_NUM]; unsigned long init_regs_bitmap; @@ -77,6 +88,92 @@ struct cm32181_chip { const int *als_it_values; }; +static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2); + +#ifdef CONFIG_ACPI +/** + * cm32181_acpi_get_cpm() - Get CPM object from ACPI + * @client pointer of struct i2c_client. + * @obj_name pointer of ACPI object name. + * @count maximum size of return array. + * @vals pointer of array for return elements. + * + * Convert ACPI CPM table to array. + * + * Return: -ENODEV for fail. Otherwise is number of elements. + */ +static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name, + u64 *values, int count) +{ + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *cpm, *elem; + acpi_handle handle; + acpi_status status; + int i; + + handle = ACPI_HANDLE(dev); + if (!handle) + return -ENODEV; + + status = acpi_evaluate_object(handle, obj_name, NULL, &buffer); + if (ACPI_FAILURE(status)) { + dev_err(dev, "object %s not found\n", obj_name); + return -ENODEV; + } + + cpm = buffer.pointer; + if (cpm->package.count > count) + dev_warn(dev, "%s table contains %u values, only using first %d values\n", + obj_name, cpm->package.count, count); + + count = min_t(int, cpm->package.count, count); + for (i = 0; i < count; i++) { + elem = &(cpm->package.elements[i]); + values[i] = elem->integer.value; + } + + kfree(buffer.pointer); + + return count; +} + +static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181) +{ + u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM]; + struct device *dev = cm32181->dev; + int i, count; + + count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals)); + if (count <= CPM0_HEADER_SIZE) + return; + + count -= CPM0_HEADER_SIZE; + + cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP]; + cm32181->init_regs_bitmap &= GENMASK(count - 1, 0); + for_each_set_bit(i, &cm32181->init_regs_bitmap, count) + cm32181->conf_regs[i] = vals[CPM0_HEADER_SIZE + i]; + + count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals)); + if (count != CPM1_SIZE) + return; + + cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT]; + + /* Check for uncalibrated devices */ + if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT) + return; + + cm32181->calibscale = vals[CPM1_CALIBSCALE]; + /* CPM1 lux_per_bit is for the current it value */ + cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it); +} +#else +static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181) +{ +} +#endif /* CONFIG_ACPI */ + /** * cm32181_reg_init() - Initialize CM32181 registers * @cm32181: pointer of struct cm32181. @@ -120,6 +217,9 @@ static int cm32181_reg_init(struct cm32181_chip *cm32181) cm32181->lux_per_bit = CM32181_LUX_PER_BIT; cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT; + if (ACPI_HANDLE(cm32181->dev)) + cm32181_acpi_parse_cpm_tables(cm32181); + /* Initialize registers*/ for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) { ret = i2c_smbus_write_word_data(client, i, @@ -362,6 +462,7 @@ static int cm32181_probe(struct i2c_client *client) cm32181 = iio_priv(indio_dev); cm32181->client = client; + cm32181->dev = dev; mutex_init(&cm32181->lock); indio_dev->dev.parent = dev; |