Messages in this thread | | | Subject | Re: [PATCH 7/8] iio: light: cm32181: Add support for parsing CPM0 and CPM1 ACPI tables | From | Hans de Goede <> | Date | Mon, 27 Apr 2020 17:31:24 +0200 |
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Hi,
On 4/26/20 7:50 PM, Andy Shevchenko wrote: > On Sun, Apr 26, 2020 at 2:03 PM Hans de Goede <hdegoede@redhat.com> wrote: >> >> On ACPI based systems the CPLM3218 ACPI device node describing the >> CM3218[1] sensor typically will have some extra tables with register >> init values for initializing the sensor and calibration info. >> >> This is based on a newer version of cm32181.c, with a copyright of: >> >> * Copyright (C) 2014 Capella Microsystems Inc. >> * Author: Kevin Tsai <ktsai@capellamicro.com> >> * >> * This program is free software; you can redistribute it and/or modify it >> * under the terms of the GNU General Public License version 2, as published >> * by the Free Software Foundation. >> >> Which is floating around on the net in various places, but the changes >> from this newer version never made it upstream. >> >> This was tested on the following models: Acer Switch 10 SW5-012 (CM32181) >> Asus T100TA (CM3218), Asus T100CHI (CM3218) and HP X2 10-n000nd (CM32181). >> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >> --- >> drivers/iio/light/cm32181.c | 98 +++++++++++++++++++++++++++++++++++++ >> 1 file changed, 98 insertions(+) >> >> diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c >> index e5674d4a8143..878fc13632d8 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> >> @@ -53,6 +54,15 @@ >> >> #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 }; >> @@ -76,6 +86,56 @@ 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 i2c_client *client, 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(&client->dev); >> + if (!handle) >> + return -ENODEV; >> + >> + status = acpi_evaluate_object(handle, obj_name, NULL, &buffer); >> + if (ACPI_FAILURE(status)) { >> + dev_err(&client->dev, "object %s not found\n", obj_name); >> + return -ENODEV; >> + } >> + >> + cpm = buffer.pointer; >> + if (cpm->package.count > count) >> + dev_warn(&client->dev, "%s table contains %d 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; >> +} >> +#endif /* CONFIG_ACPI */ >> + >> /** >> * cm32181_reg_init() - Initialize CM32181 registers >> * @cm32181: pointer of struct cm32181. >> @@ -121,6 +181,44 @@ 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; >> >> +#ifdef CONFIG_ACPI >> + if (ACPI_HANDLE(&client->dev)) { >> + u64 values[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM]; >> + int count; >> + >> + count = cm32181_acpi_get_cpm(client, "CPM0", >> + values, ARRAY_SIZE(values)); >> + if (count <= CPM0_HEADER_SIZE) >> + goto cpm_parsing_done; >> + >> + count -= CPM0_HEADER_SIZE; >> + >> + cm32181->init_regs_bitmap = values[CPM0_REGS_BITMAP]; >> + cm32181->init_regs_bitmap &= GENMASK(count - 1, 0); >> + for (i = 0; i < count; i++) { >> + if (cm32181->init_regs_bitmap & BIT(i)) >> + cm32181->conf_regs[i] = >> + values[CPM0_HEADER_SIZE + i]; >> + } >> + >> + count = cm32181_acpi_get_cpm(client, "CPM1", >> + values, ARRAY_SIZE(values)); >> + if (count != CPM1_SIZE) >> + goto cpm_parsing_done; >> + >> + cm32181->lux_per_bit = values[CPM1_LUX_PER_BIT]; >> + >> + /* Check for uncalibrated devices */ >> + if (values[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT) >> + goto cpm_parsing_done; >> + >> + cm32181->calibscale = values[CPM1_CALIBSCALE]; >> + /* CPM1 lux_per_bit is for the current it value */ >> + cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it); >> + } >> +cpm_parsing_done: > > Perhaps factor out to a helper, will > a) allow to get rid of a label; > b) drop indentation level.
Thank you for the reviews.
Factoring this into a helper is a good idea, that will also allow getting rid of 1 of the CONFIG_ACPI #ifdef-s.
I also agree with your comments on the other patches.
I'll prepare and test a v2 with these changes and then submit it with your Reviewed-by added.
Regards,
Hans
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