| Message ID | 20210113200010.71845-4-tmaimon77@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add NPCM7xx patches to dev-5.8 | expand |
On Wed, 13 Jan 2021 at 20:00, Tomer Maimon <tmaimon77@gmail.com> wrote: > > Add calibration to improve accuracy measurement when using > internal reference voltage. > > the calibration values taken from the FUSE module. > > Signed-off-by: Tomer Maimon <tmaimon77@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> When submitting this to mainline you should consider putting the fuse reading code in it's own driver if it is to be used by other components in your system. > --- > drivers/iio/adc/npcm_adc.c | 178 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 178 insertions(+) > > diff --git a/drivers/iio/adc/npcm_adc.c b/drivers/iio/adc/npcm_adc.c > index 83bad2d5575d..081378b98fa9 100644 > --- a/drivers/iio/adc/npcm_adc.c > +++ b/drivers/iio/adc/npcm_adc.c > @@ -17,6 +17,8 @@ > #include <linux/reset.h> > > struct npcm_adc { > + u32 R05; > + u32 R15; > bool int_status; > u32 adc_sample_hz; > struct device *dev; > @@ -51,6 +53,41 @@ struct npcm_adc { > #define NPCM_RESOLUTION_BITS 10 > #define NPCM_INT_VREF_MV 2000 > > +/* FUSE registers */ > +#define NPCM7XX_FST 0x00 > +#define NPCM7XX_FADDR 0x04 > +#define NPCM7XX_FDATA 0x08 > +#define NPCM7XX_FCFG 0x0C > +#define NPCM7XX_FCTL 0x14 > + > +/* FST Register Bits */ > +#define NPCM7XX_FST_RDY BIT(0) > +#define NPCM7XX_FST_RDST BIT(1) > + > +/* FADDR Register Bits */ > +#define NPCM7XX_FADDR_BYTEADDR BIT(0) > +#define NPCM7XX_FADDR_BYTEADDR_MASK GENMASK(9, 0) > + > +/* FADDR Register Bits */ > +#define NPCM7XX_FDATA_DATA BIT(0) > +#define NPCM7XX_FDATA_CLEAN_VALUE BIT(1) > +#define NPCM7XX_FDATA_DATA_MASK GENMASK(7, 0) > + > +/* FCTL Register Bits */ > +#define NPCM7XX_FCTL_RDST BIT(1) > + > +/* ADC Calibration Definition */ > +#define NPCM_INT_1500MV 768 > +#define NPCM_INT_1000MV 512 > +#define NPCM_ADC_MIN_VAL 0 > +#define NPCM_ADC_MAX_VAL 1023 > + > +#define FUSE_CALIB_ADDR 24 > +#define FUSE_CALIB_SIZE 8 > +#define DATA_CALIB_SIZE 4 > +#define FUSE_READ_SLEEP 500 > +#define FUSE_READ_TIMEOUT 1000000 > + > #define NPCM_ADC_CHAN(ch) { \ > .type = IIO_VOLTAGE, \ > .indexed = 1, \ > @@ -71,6 +108,119 @@ static const struct iio_chan_spec npcm_adc_iio_channels[] = { > NPCM_ADC_CHAN(7), > }; > > +static void npcm750_fuse_read(struct regmap *fuse_regmap, u32 addr, u8 *data) > +{ > + u32 val; > + u32 fstreg; > + > + regmap_read_poll_timeout(fuse_regmap, NPCM7XX_FST, fstreg, > + fstreg & NPCM7XX_FST_RDY, FUSE_READ_SLEEP, > + FUSE_READ_TIMEOUT); > + regmap_write_bits(fuse_regmap, NPCM7XX_FST, > + NPCM7XX_FST_RDST, NPCM7XX_FST_RDST); > + > + regmap_write_bits(fuse_regmap, NPCM7XX_FADDR, > + NPCM7XX_FADDR_BYTEADDR_MASK, addr); > + regmap_read(fuse_regmap, NPCM7XX_FADDR, &val); > + regmap_write(fuse_regmap, NPCM7XX_FCTL, NPCM7XX_FCTL_RDST); > + > + regmap_read_poll_timeout(fuse_regmap, NPCM7XX_FST, fstreg, > + fstreg & NPCM7XX_FST_RDY, FUSE_READ_SLEEP, > + FUSE_READ_TIMEOUT); > + regmap_write_bits(fuse_regmap, NPCM7XX_FST, > + NPCM7XX_FST_RDST, NPCM7XX_FST_RDST); > + > + regmap_read(fuse_regmap, NPCM7XX_FDATA, &val); > + *data = (u8)val; > + > + regmap_write_bits(fuse_regmap, NPCM7XX_FDATA, NPCM7XX_FDATA_DATA_MASK, > + NPCM7XX_FDATA_CLEAN_VALUE); > +} > + > +static int npcm750_ECC_to_nibble(u8 ECC, u8 nibble) > +{ > + u8 nibble_b0 = (nibble >> 0) & BIT(0); > + u8 nibble_b1 = (nibble >> 1) & BIT(0); > + u8 nibble_b2 = (nibble >> 2) & BIT(0); > + u8 nibble_b3 = (nibble >> 3) & BIT(0); > + u8 tmp_ECC = nibble; > + > + tmp_ECC |= (nibble_b0 ^ nibble_b1) << 4 | (nibble_b2 ^ nibble_b3) << 5 | > + (nibble_b0 ^ nibble_b2) << 6 | (nibble_b1 ^ nibble_b3) << 7; > + > + if (tmp_ECC != ECC) > + return -EINVAL; > + > + return 0; > +} > + > +static int npcm750_ECC_to_byte(u16 ECC, u8 *Byte) > +{ > + u8 nibble_L, nibble_H; > + u8 ECC_L, ECC_H; > + > + ECC_H = ECC >> 8; > + nibble_H = ECC_H & 0x0F; > + ECC_L = ECC >> 0; > + nibble_L = ECC_L & 0x0F; > + > + if (npcm750_ECC_to_nibble(ECC_H, nibble_H) != 0 || > + npcm750_ECC_to_nibble(ECC_L, nibble_L) != 0) > + return -EINVAL; > + > + *Byte = nibble_H << 4 | nibble_L << 0; > + > + return 0; > +} > + > +static int npcm750_read_nibble_parity(u8 *block_ECC, u8 *ADC_calib) > +{ > + int i; > + u16 ECC; > + > + for (i = 0; i < DATA_CALIB_SIZE; i++) { > + memcpy(&ECC, block_ECC + (i * 2), 2); > + if (npcm750_ECC_to_byte(ECC, &ADC_calib[i]) != 0) > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int npcm750_fuse_calibration_read(struct platform_device *pdev, > + struct npcm_adc *info) > +{ > + struct device_node *np = pdev->dev.of_node; > + struct regmap *fuse_regmap; > + ssize_t bytes_read = 0; > + u8 read_buf[8]; > + u32 ADC_calib; > + u32 addr = FUSE_CALIB_ADDR; > + > + fuse_regmap = syscon_regmap_lookup_by_phandle(np, "syscon"); > + if (IS_ERR(fuse_regmap)) { > + dev_warn(&pdev->dev, "Failed to find syscon\n"); > + return PTR_ERR(fuse_regmap); > + } > + > + while (bytes_read < FUSE_CALIB_SIZE) { > + npcm750_fuse_read(fuse_regmap, addr, > + &read_buf[bytes_read]); > + bytes_read++; > + addr++; > + } > + > + if (npcm750_read_nibble_parity(read_buf, (u8 *)&ADC_calib)) { > + dev_warn(info->dev, "FUSE Calibration read failed\n"); > + return -EINVAL; > + } > + > + info->R05 = ADC_calib & 0xFFFF; > + info->R15 = ADC_calib >> 16; > + > + return 0; > +} > + > static irqreturn_t npcm_adc_isr(int irq, void *data) > { > u32 regtemp; > @@ -125,6 +275,29 @@ static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel) > return 0; > } > > +static void npcm_adc_calibration(int *val, struct npcm_adc *info) > +{ > + int mul_val; > + int offset_val; > + > + mul_val = NPCM_INT_1000MV * (*val - info->R15); > + if (mul_val < 0) { > + mul_val = mul_val * -1; > + offset_val = DIV_ROUND_CLOSEST(mul_val, > + (info->R15 - info->R05)); > + *val = NPCM_INT_1500MV - offset_val; > + } else { > + offset_val = DIV_ROUND_CLOSEST(mul_val, > + (info->R15 - info->R05)); > + *val = NPCM_INT_1500MV + offset_val; > + } > + > + if (*val < NPCM_ADC_MIN_VAL) > + *val = NPCM_ADC_MIN_VAL; > + if (*val > NPCM_ADC_MAX_VAL) > + *val = NPCM_ADC_MAX_VAL; > +} > + > static int npcm_adc_read_raw(struct iio_dev *indio_dev, > struct iio_chan_spec const *chan, int *val, > int *val2, long mask) > @@ -142,6 +315,10 @@ static int npcm_adc_read_raw(struct iio_dev *indio_dev, > dev_err(info->dev, "NPCM ADC read failed\n"); > return ret; > } > + > + if ((info->R05 || info->R15) && IS_ERR(info->vref)) > + npcm_adc_calibration(val, info); > + > return IIO_VAL_INT; > case IIO_CHAN_INFO_SCALE: > if (!IS_ERR(info->vref)) { > @@ -248,6 +425,7 @@ static int npcm_adc_probe(struct platform_device *pdev) > info->regs + NPCM_ADCCON); > } > > + npcm750_fuse_calibration_read(pdev, info); > init_waitqueue_head(&info->wq); > > reg_con = ioread32(info->regs + NPCM_ADCCON); > -- > 2.22.0 >
diff --git a/drivers/iio/adc/npcm_adc.c b/drivers/iio/adc/npcm_adc.c index 83bad2d5575d..081378b98fa9 100644 --- a/drivers/iio/adc/npcm_adc.c +++ b/drivers/iio/adc/npcm_adc.c @@ -17,6 +17,8 @@ #include <linux/reset.h> struct npcm_adc { + u32 R05; + u32 R15; bool int_status; u32 adc_sample_hz; struct device *dev; @@ -51,6 +53,41 @@ struct npcm_adc { #define NPCM_RESOLUTION_BITS 10 #define NPCM_INT_VREF_MV 2000 +/* FUSE registers */ +#define NPCM7XX_FST 0x00 +#define NPCM7XX_FADDR 0x04 +#define NPCM7XX_FDATA 0x08 +#define NPCM7XX_FCFG 0x0C +#define NPCM7XX_FCTL 0x14 + +/* FST Register Bits */ +#define NPCM7XX_FST_RDY BIT(0) +#define NPCM7XX_FST_RDST BIT(1) + +/* FADDR Register Bits */ +#define NPCM7XX_FADDR_BYTEADDR BIT(0) +#define NPCM7XX_FADDR_BYTEADDR_MASK GENMASK(9, 0) + +/* FADDR Register Bits */ +#define NPCM7XX_FDATA_DATA BIT(0) +#define NPCM7XX_FDATA_CLEAN_VALUE BIT(1) +#define NPCM7XX_FDATA_DATA_MASK GENMASK(7, 0) + +/* FCTL Register Bits */ +#define NPCM7XX_FCTL_RDST BIT(1) + +/* ADC Calibration Definition */ +#define NPCM_INT_1500MV 768 +#define NPCM_INT_1000MV 512 +#define NPCM_ADC_MIN_VAL 0 +#define NPCM_ADC_MAX_VAL 1023 + +#define FUSE_CALIB_ADDR 24 +#define FUSE_CALIB_SIZE 8 +#define DATA_CALIB_SIZE 4 +#define FUSE_READ_SLEEP 500 +#define FUSE_READ_TIMEOUT 1000000 + #define NPCM_ADC_CHAN(ch) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ @@ -71,6 +108,119 @@ static const struct iio_chan_spec npcm_adc_iio_channels[] = { NPCM_ADC_CHAN(7), }; +static void npcm750_fuse_read(struct regmap *fuse_regmap, u32 addr, u8 *data) +{ + u32 val; + u32 fstreg; + + regmap_read_poll_timeout(fuse_regmap, NPCM7XX_FST, fstreg, + fstreg & NPCM7XX_FST_RDY, FUSE_READ_SLEEP, + FUSE_READ_TIMEOUT); + regmap_write_bits(fuse_regmap, NPCM7XX_FST, + NPCM7XX_FST_RDST, NPCM7XX_FST_RDST); + + regmap_write_bits(fuse_regmap, NPCM7XX_FADDR, + NPCM7XX_FADDR_BYTEADDR_MASK, addr); + regmap_read(fuse_regmap, NPCM7XX_FADDR, &val); + regmap_write(fuse_regmap, NPCM7XX_FCTL, NPCM7XX_FCTL_RDST); + + regmap_read_poll_timeout(fuse_regmap, NPCM7XX_FST, fstreg, + fstreg & NPCM7XX_FST_RDY, FUSE_READ_SLEEP, + FUSE_READ_TIMEOUT); + regmap_write_bits(fuse_regmap, NPCM7XX_FST, + NPCM7XX_FST_RDST, NPCM7XX_FST_RDST); + + regmap_read(fuse_regmap, NPCM7XX_FDATA, &val); + *data = (u8)val; + + regmap_write_bits(fuse_regmap, NPCM7XX_FDATA, NPCM7XX_FDATA_DATA_MASK, + NPCM7XX_FDATA_CLEAN_VALUE); +} + +static int npcm750_ECC_to_nibble(u8 ECC, u8 nibble) +{ + u8 nibble_b0 = (nibble >> 0) & BIT(0); + u8 nibble_b1 = (nibble >> 1) & BIT(0); + u8 nibble_b2 = (nibble >> 2) & BIT(0); + u8 nibble_b3 = (nibble >> 3) & BIT(0); + u8 tmp_ECC = nibble; + + tmp_ECC |= (nibble_b0 ^ nibble_b1) << 4 | (nibble_b2 ^ nibble_b3) << 5 | + (nibble_b0 ^ nibble_b2) << 6 | (nibble_b1 ^ nibble_b3) << 7; + + if (tmp_ECC != ECC) + return -EINVAL; + + return 0; +} + +static int npcm750_ECC_to_byte(u16 ECC, u8 *Byte) +{ + u8 nibble_L, nibble_H; + u8 ECC_L, ECC_H; + + ECC_H = ECC >> 8; + nibble_H = ECC_H & 0x0F; + ECC_L = ECC >> 0; + nibble_L = ECC_L & 0x0F; + + if (npcm750_ECC_to_nibble(ECC_H, nibble_H) != 0 || + npcm750_ECC_to_nibble(ECC_L, nibble_L) != 0) + return -EINVAL; + + *Byte = nibble_H << 4 | nibble_L << 0; + + return 0; +} + +static int npcm750_read_nibble_parity(u8 *block_ECC, u8 *ADC_calib) +{ + int i; + u16 ECC; + + for (i = 0; i < DATA_CALIB_SIZE; i++) { + memcpy(&ECC, block_ECC + (i * 2), 2); + if (npcm750_ECC_to_byte(ECC, &ADC_calib[i]) != 0) + return -EINVAL; + } + + return 0; +} + +static int npcm750_fuse_calibration_read(struct platform_device *pdev, + struct npcm_adc *info) +{ + struct device_node *np = pdev->dev.of_node; + struct regmap *fuse_regmap; + ssize_t bytes_read = 0; + u8 read_buf[8]; + u32 ADC_calib; + u32 addr = FUSE_CALIB_ADDR; + + fuse_regmap = syscon_regmap_lookup_by_phandle(np, "syscon"); + if (IS_ERR(fuse_regmap)) { + dev_warn(&pdev->dev, "Failed to find syscon\n"); + return PTR_ERR(fuse_regmap); + } + + while (bytes_read < FUSE_CALIB_SIZE) { + npcm750_fuse_read(fuse_regmap, addr, + &read_buf[bytes_read]); + bytes_read++; + addr++; + } + + if (npcm750_read_nibble_parity(read_buf, (u8 *)&ADC_calib)) { + dev_warn(info->dev, "FUSE Calibration read failed\n"); + return -EINVAL; + } + + info->R05 = ADC_calib & 0xFFFF; + info->R15 = ADC_calib >> 16; + + return 0; +} + static irqreturn_t npcm_adc_isr(int irq, void *data) { u32 regtemp; @@ -125,6 +275,29 @@ static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel) return 0; } +static void npcm_adc_calibration(int *val, struct npcm_adc *info) +{ + int mul_val; + int offset_val; + + mul_val = NPCM_INT_1000MV * (*val - info->R15); + if (mul_val < 0) { + mul_val = mul_val * -1; + offset_val = DIV_ROUND_CLOSEST(mul_val, + (info->R15 - info->R05)); + *val = NPCM_INT_1500MV - offset_val; + } else { + offset_val = DIV_ROUND_CLOSEST(mul_val, + (info->R15 - info->R05)); + *val = NPCM_INT_1500MV + offset_val; + } + + if (*val < NPCM_ADC_MIN_VAL) + *val = NPCM_ADC_MIN_VAL; + if (*val > NPCM_ADC_MAX_VAL) + *val = NPCM_ADC_MAX_VAL; +} + static int npcm_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) @@ -142,6 +315,10 @@ static int npcm_adc_read_raw(struct iio_dev *indio_dev, dev_err(info->dev, "NPCM ADC read failed\n"); return ret; } + + if ((info->R05 || info->R15) && IS_ERR(info->vref)) + npcm_adc_calibration(val, info); + return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (!IS_ERR(info->vref)) { @@ -248,6 +425,7 @@ static int npcm_adc_probe(struct platform_device *pdev) info->regs + NPCM_ADCCON); } + npcm750_fuse_calibration_read(pdev, info); init_waitqueue_head(&info->wq); reg_con = ioread32(info->regs + NPCM_ADCCON);
Add calibration to improve accuracy measurement when using internal reference voltage. the calibration values taken from the FUSE module. Signed-off-by: Tomer Maimon <tmaimon77@gmail.com> --- drivers/iio/adc/npcm_adc.c | 178 +++++++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+)