diff options
Diffstat (limited to 'drivers/iio/adc/npcm_adc.c')
| -rw-r--r-- | drivers/iio/adc/npcm_adc.c | 63 |
1 files changed, 47 insertions, 16 deletions
diff --git a/drivers/iio/adc/npcm_adc.c b/drivers/iio/adc/npcm_adc.c index 83bad2d5575d..c8283873cdee 100644 --- a/drivers/iio/adc/npcm_adc.c +++ b/drivers/iio/adc/npcm_adc.c @@ -8,14 +8,22 @@ #include <linux/iio/iio.h> #include <linux/interrupt.h> #include <linux/kernel.h> +#include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/platform_device.h> +#include <linux/property.h> #include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/spinlock.h> #include <linux/uaccess.h> #include <linux/reset.h> +struct npcm_adc_info { + u32 data_mask; + u32 internal_vref; + u32 res_bits; +}; + struct npcm_adc { bool int_status; u32 adc_sample_hz; @@ -25,6 +33,16 @@ struct npcm_adc { wait_queue_head_t wq; struct regulator *vref; struct reset_control *reset; + /* + * Lock to protect the device state during a potential concurrent + * read access from userspace. Reading a raw value requires a sequence + * of register writes, then a wait for a event and finally a register + * read, during which userspace could issue another read request. + * This lock protects a read access from ocurring before another one + * has finished. + */ + struct mutex lock; + const struct npcm_adc_info *data; }; /* ADC registers */ @@ -43,13 +61,21 @@ struct npcm_adc { #define NPCM_ADCCON_CH(x) ((x) << 24) #define NPCM_ADCCON_DIV_SHIFT 1 #define NPCM_ADCCON_DIV_MASK GENMASK(8, 1) -#define NPCM_ADC_DATA_MASK(x) ((x) & GENMASK(9, 0)) #define NPCM_ADC_ENABLE (NPCM_ADCCON_ADC_EN | NPCM_ADCCON_ADC_INT_EN) /* ADC General Definition */ -#define NPCM_RESOLUTION_BITS 10 -#define NPCM_INT_VREF_MV 2000 +static const struct npcm_adc_info npxm7xx_adc_info = { + .data_mask = GENMASK(9, 0), + .internal_vref = 2048, + .res_bits = 10, +}; + +static const struct npcm_adc_info npxm8xx_adc_info = { + .data_mask = GENMASK(11, 0), + .internal_vref = 1229, + .res_bits = 12, +}; #define NPCM_ADC_CHAN(ch) { \ .type = IIO_VOLTAGE, \ @@ -120,7 +146,8 @@ static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel) if (ret < 0) return ret; - *val = NPCM_ADC_DATA_MASK(ioread32(info->regs + NPCM_ADCDATA)); + *val = ioread32(info->regs + NPCM_ADCDATA); + *val &= info->data->data_mask; return 0; } @@ -135,9 +162,9 @@ static int npcm_adc_read_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_RAW: - mutex_lock(&indio_dev->mlock); + mutex_lock(&info->lock); ret = npcm_adc_read(info, val, chan->channel); - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&info->lock); if (ret) { dev_err(info->dev, "NPCM ADC read failed\n"); return ret; @@ -148,9 +175,9 @@ static int npcm_adc_read_raw(struct iio_dev *indio_dev, vref_uv = regulator_get_voltage(info->vref); *val = vref_uv / 1000; } else { - *val = NPCM_INT_VREF_MV; + *val = info->data->internal_vref; } - *val2 = NPCM_RESOLUTION_BITS; + *val2 = info->data->res_bits; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_SAMP_FREQ: *val = info->adc_sample_hz; @@ -167,8 +194,9 @@ static const struct iio_info npcm_adc_iio_info = { }; static const struct of_device_id npcm_adc_match[] = { - { .compatible = "nuvoton,npcm750-adc", }, - { /* sentinel */ } + { .compatible = "nuvoton,npcm750-adc", .data = &npxm7xx_adc_info}, + { .compatible = "nuvoton,npcm845-adc", .data = &npxm8xx_adc_info}, + { } }; MODULE_DEVICE_TABLE(of, npcm_adc_match); @@ -187,6 +215,12 @@ static int npcm_adc_probe(struct platform_device *pdev) return -ENOMEM; info = iio_priv(indio_dev); + info->data = device_get_match_data(dev); + if (!info->data) + return -EINVAL; + + mutex_init(&info->lock); + info->dev = &pdev->dev; info->regs = devm_platform_ioremap_resource(pdev, 0); @@ -210,8 +244,8 @@ static int npcm_adc_probe(struct platform_device *pdev) info->adc_sample_hz = clk_get_rate(info->adc_clk) / ((div + 1) * 2); irq = platform_get_irq(pdev, 0); - if (irq <= 0) { - ret = -EINVAL; + if (irq < 0) { + ret = irq; goto err_disable_clk; } @@ -261,7 +295,6 @@ static int npcm_adc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, indio_dev); indio_dev->name = dev_name(&pdev->dev); - indio_dev->dev.parent = &pdev->dev; indio_dev->info = &npcm_adc_iio_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = npcm_adc_iio_channels; @@ -287,7 +320,7 @@ err_disable_clk: return ret; } -static int npcm_adc_remove(struct platform_device *pdev) +static void npcm_adc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct npcm_adc *info = iio_priv(indio_dev); @@ -300,8 +333,6 @@ static int npcm_adc_remove(struct platform_device *pdev) if (!IS_ERR(info->vref)) regulator_disable(info->vref); clk_disable_unprepare(info->adc_clk); - - return 0; } static struct platform_driver npcm_adc_driver = { |