// SPDX-License-Identifier: GPL-2.0-only /* * Analog Devices AD9739a SPI DAC driver * * Copyright 2015-2024 Analog Devices Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define AD9739A_REG_MODE 0 #define AD9739A_RESET_MASK BIT(5) #define AD9739A_REG_FSC_1 0x06 #define AD9739A_REG_FSC_2 0x07 #define AD9739A_FSC_MSB GENMASK(1, 0) #define AD9739A_REG_DEC_CNT 0x8 #define AD9739A_NORMAL_MODE 0 #define AD9739A_MIXED_MODE 2 #define AD9739A_DAC_DEC GENMASK(1, 0) #define AD9739A_REG_LVDS_REC_CNT1 0x10 #define AD9739A_RCVR_LOOP_EN_MASK GENMASK(1, 0) #define AD9739A_REG_LVDS_REC_CNT4 0x13 #define AD9739A_FINE_DEL_SKW_MASK GENMASK(3, 0) #define AD9739A_REG_LVDS_REC_STAT9 0x21 #define AD9739A_RCVR_TRACK_AND_LOCK (BIT(3) | BIT(0)) #define AD9739A_REG_CROSS_CNT1 0x22 #define AD9739A_REG_CROSS_CNT2 0x23 #define AD9739A_REG_PHS_DET 0x24 #define AD9739A_REG_MU_DUTY 0x25 #define AD9739A_REG_MU_CNT1 0x26 #define AD9739A_MU_EN_MASK BIT(0) #define AD9739A_MU_GAIN_MASK BIT(1) #define AD9739A_REG_MU_CNT2 0x27 #define AD9739A_REG_MU_CNT3 0x28 #define AD9739A_REG_MU_CNT4 0x29 #define AD9739A_MU_CNT4_DEFAULT 0xcb #define AD9739A_REG_MU_STAT1 0x2A #define AD9739A_MU_LOCK_MASK BIT(0) #define AD9739A_REG_ANA_CNT_1 0x32 #define AD9739A_REG_ID 0x35 #define AD9739A_ID 0x24 #define AD9739A_REG_IS_RESERVED(reg) \ ((reg) == 0x5 || (reg) == 0x9 || (reg) == 0x0E || (reg) == 0x0D || \ (reg) == 0x2B || (reg) == 0x2C || (reg) == 0x34) #define AD9739A_FSC_MIN 8580 #define AD9739A_FSC_MAX 31700 #define AD9739A_FSC_RANGE (AD9739A_FSC_MAX - AD9739A_FSC_MIN + 1) #define AD9739A_MIN_DAC_CLK (1600 * MEGA) #define AD9739A_MAX_DAC_CLK (2500 * MEGA) #define AD9739A_DAC_CLK_RANGE (AD9739A_MAX_DAC_CLK - AD9739A_MIN_DAC_CLK + 1) /* as recommended by the datasheet */ #define AD9739A_LOCK_N_TRIES 3 struct ad9739a_state { struct iio_backend *back; struct regmap *regmap; unsigned long sample_rate; }; static int ad9739a_oper_mode_get(struct iio_dev *indio_dev, const struct iio_chan_spec *chan) { struct ad9739a_state *st = iio_priv(indio_dev); u32 mode; int ret; ret = regmap_read(st->regmap, AD9739A_REG_DEC_CNT, &mode); if (ret) return ret; mode = FIELD_GET(AD9739A_DAC_DEC, mode); /* sanity check we get valid values from the HW */ if (mode != AD9739A_NORMAL_MODE && mode != AD9739A_MIXED_MODE) return -EIO; if (!mode) return AD9739A_NORMAL_MODE; /* * We get 2 from the device but for IIO modes, that means 1. Hence the * minus 1. */ return AD9739A_MIXED_MODE - 1; } static int ad9739a_oper_mode_set(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, u32 mode) { struct ad9739a_state *st = iio_priv(indio_dev); /* * On the IIO interface we have 0 and 1 for mode. But for mixed_mode, we * need to write 2 in the device. That's what the below check is about. */ if (mode == AD9739A_MIXED_MODE - 1) mode = AD9739A_MIXED_MODE; return regmap_update_bits(st->regmap, AD9739A_REG_DEC_CNT, AD9739A_DAC_DEC, mode); } static int ad9739a_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct ad9739a_state *st = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: *val = st->sample_rate; *val2 = 0; return IIO_VAL_INT_64; default: return -EINVAL; } } static int ad9739a_buffer_preenable(struct iio_dev *indio_dev) { struct ad9739a_state *st = iio_priv(indio_dev); return iio_backend_data_source_set(st->back, 0, IIO_BACKEND_EXTERNAL); } static int ad9739a_buffer_postdisable(struct iio_dev *indio_dev) { struct ad9739a_state *st = iio_priv(indio_dev); return iio_backend_data_source_set(st->back, 0, IIO_BACKEND_INTERNAL_CONTINUOS_WAVE); } static bool ad9739a_reg_accessible(struct device *dev, unsigned int reg) { if (AD9739A_REG_IS_RESERVED(reg)) return false; if (reg > AD9739A_REG_MU_STAT1 && reg < AD9739A_REG_ANA_CNT_1) return false; return true; } static int ad9739a_reset(struct device *dev, const struct ad9739a_state *st) { struct gpio_desc *gpio; int ret; gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(gpio)) return PTR_ERR(gpio); if (gpio) { /* minimum pulse width of 40ns */ ndelay(40); gpiod_set_value_cansleep(gpio, 0); return 0; } /* bring all registers to their default state */ ret = regmap_set_bits(st->regmap, AD9739A_REG_MODE, AD9739A_RESET_MASK); if (ret) return ret; ndelay(40); return regmap_clear_bits(st->regmap, AD9739A_REG_MODE, AD9739A_RESET_MASK); } /* * Recommended values (as per datasheet) for the dac clk common mode voltage * and Mu controller. Look at table 29. */ static const struct reg_sequence ad9739a_clk_mu_ctrl[] = { /* DAC clk common mode voltage */ { AD9739A_REG_CROSS_CNT1, 0x0f }, { AD9739A_REG_CROSS_CNT2, 0x0f }, /* Mu controller configuration */ { AD9739A_REG_PHS_DET, 0x30 }, { AD9739A_REG_MU_DUTY, 0x80 }, { AD9739A_REG_MU_CNT2, 0x44 }, { AD9739A_REG_MU_CNT3, 0x6c }, }; static int ad9739a_init(struct device *dev, const struct ad9739a_state *st) { unsigned int i = 0, lock, fsc; u32 fsc_raw; int ret; ret = regmap_multi_reg_write(st->regmap, ad9739a_clk_mu_ctrl, ARRAY_SIZE(ad9739a_clk_mu_ctrl)); if (ret) return ret; /* * Try to get the Mu lock. Repeat the below steps AD9739A_LOCK_N_TRIES * (as specified by the datasheet) until we get the lock. */ do { ret = regmap_write(st->regmap, AD9739A_REG_MU_CNT4, AD9739A_MU_CNT4_DEFAULT); if (ret) return ret; /* Enable the Mu controller search and track mode. */ ret = regmap_write(st->regmap, AD9739A_REG_MU_CNT1, AD9739A_MU_EN_MASK | AD9739A_MU_GAIN_MASK); if (ret) return ret; /* Ensure the DLL loop is locked */ ret = regmap_read_poll_timeout(st->regmap, AD9739A_REG_MU_STAT1, lock, lock & AD9739A_MU_LOCK_MASK, 0, 1000); if (ret && ret != -ETIMEDOUT) return ret; } while (ret && ++i < AD9739A_LOCK_N_TRIES); if (i == AD9739A_LOCK_N_TRIES) return dev_err_probe(dev, ret, "Mu lock timeout\n"); /* Receiver tracking and lock. Same deal as the Mu controller */ i = 0; do { ret = regmap_update_bits(st->regmap, AD9739A_REG_LVDS_REC_CNT4, AD9739A_FINE_DEL_SKW_MASK, FIELD_PREP(AD9739A_FINE_DEL_SKW_MASK, 2)); if (ret) return ret; /* Disable the receiver and the loop. */ ret = regmap_write(st->regmap, AD9739A_REG_LVDS_REC_CNT1, 0); if (ret) return ret; /* * Re-enable the loop so it falls out of lock and begins the * search/track routine again. */ ret = regmap_set_bits(st->regmap, AD9739A_REG_LVDS_REC_CNT1, AD9739A_RCVR_LOOP_EN_MASK); if (ret) return ret; /* Ensure the DLL loop is locked */ ret = regmap_read_poll_timeout(st->regmap, AD9739A_REG_LVDS_REC_STAT9, lock, lock == AD9739A_RCVR_TRACK_AND_LOCK, 0, 1000); if (ret && ret != -ETIMEDOUT) return ret; } while (ret && ++i < AD9739A_LOCK_N_TRIES); if (i == AD9739A_LOCK_N_TRIES) return dev_err_probe(dev, ret, "Receiver lock timeout\n"); ret = device_property_read_u32(dev, "adi,full-scale-microamp", &fsc); if (ret && ret == -EINVAL) return 0; if (ret) return ret; if (!in_range(fsc, AD9739A_FSC_MIN, AD9739A_FSC_RANGE)) return dev_err_probe(dev, -EINVAL, "Invalid full scale current(%u) [%u %u]\n", fsc, AD9739A_FSC_MIN, AD9739A_FSC_MAX); /* * IOUTFS is given by * Ioutfs = 0.0226 * FSC + 8.58 * and is given in mA. Hence we'll have to multiply by 10 * MILLI in * order to get rid of the fractional. */ fsc_raw = DIV_ROUND_CLOSEST(fsc * 10 - 85800, 226); ret = regmap_write(st->regmap, AD9739A_REG_FSC_1, fsc_raw & 0xff); if (ret) return ret; return regmap_update_bits(st->regmap, AD9739A_REG_FSC_2, AD9739A_FSC_MSB, fsc_raw >> 8); } static const char * const ad9739a_modes_avail[] = { "normal", "mixed-mode" }; static const struct iio_enum ad9739a_modes = { .items = ad9739a_modes_avail, .num_items = ARRAY_SIZE(ad9739a_modes_avail), .get = ad9739a_oper_mode_get, .set = ad9739a_oper_mode_set, }; static const struct iio_chan_spec_ext_info ad9739a_ext_info[] = { IIO_ENUM_AVAILABLE("operating_mode", IIO_SEPARATE, &ad9739a_modes), IIO_ENUM("operating_mode", IIO_SEPARATE, &ad9739a_modes), { } }; /* * The reason for having two different channels is because we have, in reality, * two sources of data: * ALTVOLTAGE: It's a Continuous Wave that's internally generated by the * backend device. * VOLTAGE: It's the typical data we can have in a DAC device and the source * of it has nothing to do with the backend. The backend will only * forward it into our data interface to be sent out. */ static struct iio_chan_spec ad9739a_channels[] = { { .type = IIO_ALTVOLTAGE, .indexed = 1, .output = 1, .scan_index = -1, }, { .type = IIO_VOLTAGE, .indexed = 1, .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), .output = 1, .ext_info = ad9739a_ext_info, .scan_type = { .sign = 's', .storagebits = 16, .realbits = 16, }, } }; static const struct iio_info ad9739a_info = { .read_raw = ad9739a_read_raw, }; static const struct iio_buffer_setup_ops ad9739a_buffer_setup_ops = { .preenable = &ad9739a_buffer_preenable, .postdisable = &ad9739a_buffer_postdisable, }; static const struct regmap_config ad9739a_regmap_config = { .reg_bits = 8, .val_bits = 8, .readable_reg = ad9739a_reg_accessible, .writeable_reg = ad9739a_reg_accessible, .max_register = AD9739A_REG_ID, }; static int ad9739a_probe(struct spi_device *spi) { struct device *dev = &spi->dev; struct iio_dev *indio_dev; struct ad9739a_state *st; unsigned int id; struct clk *clk; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); clk = devm_clk_get_enabled(dev, NULL); if (IS_ERR(clk)) return dev_err_probe(dev, PTR_ERR(clk), "Could not get clkin\n"); st->sample_rate = clk_get_rate(clk); if (!in_range(st->sample_rate, AD9739A_MIN_DAC_CLK, AD9739A_DAC_CLK_RANGE)) return dev_err_probe(dev, -EINVAL, "Invalid dac clk range(%lu) [%lu %lu]\n", st->sample_rate, AD9739A_MIN_DAC_CLK, AD9739A_MAX_DAC_CLK); st->regmap = devm_regmap_init_spi(spi, &ad9739a_regmap_config); if (IS_ERR(st->regmap)) return PTR_ERR(st->regmap); ret = regmap_read(st->regmap, AD9739A_REG_ID, &id); if (ret) return ret; if (id != AD9739A_ID) dev_warn(dev, "Unrecognized CHIP_ID 0x%X", id); ret = ad9739a_reset(dev, st); if (ret) return ret; ret = ad9739a_init(dev, st); if (ret) return ret; st->back = devm_iio_backend_get(dev, NULL); if (IS_ERR(st->back)) return PTR_ERR(st->back); ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev); if (ret) return ret; ret = iio_backend_extend_chan_spec(indio_dev, st->back, &ad9739a_channels[0]); if (ret) return ret; ret = iio_backend_set_sampling_freq(st->back, 0, st->sample_rate); if (ret) return ret; ret = devm_iio_backend_enable(dev, st->back); if (ret) return ret; indio_dev->name = "ad9739a"; indio_dev->info = &ad9739a_info; indio_dev->channels = ad9739a_channels; indio_dev->num_channels = ARRAY_SIZE(ad9739a_channels); indio_dev->setup_ops = &ad9739a_buffer_setup_ops; return devm_iio_device_register(&spi->dev, indio_dev); } static const struct of_device_id ad9739a_of_match[] = { { .compatible = "adi,ad9739a" }, {} }; MODULE_DEVICE_TABLE(of, ad9739a_of_match); static const struct spi_device_id ad9739a_id[] = { {"ad9739a"}, {} }; MODULE_DEVICE_TABLE(spi, ad9739a_id); static struct spi_driver ad9739a_driver = { .driver = { .name = "ad9739a", .of_match_table = ad9739a_of_match, }, .probe = ad9739a_probe, .id_table = ad9739a_id, }; module_spi_driver(ad9739a_driver); MODULE_AUTHOR("Dragos Bogdan "); MODULE_AUTHOR("Nuno Sa "); MODULE_DESCRIPTION("Analog Devices AD9739 DAC"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS(IIO_BACKEND);