1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * STMicroelectronics hts221 sensor driver 4 * 5 * Copyright 2016 STMicroelectronics Inc. 6 * 7 * Lorenzo Bianconi <lorenzo.bianconi@st.com> 8 */ 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/device.h> 12 #include <linux/interrupt.h> 13 #include <linux/irqreturn.h> 14 #include <linux/property.h> 15 #include <linux/regmap.h> 16 #include <linux/bitfield.h> 17 18 #include <linux/iio/iio.h> 19 #include <linux/iio/trigger.h> 20 #include <linux/iio/events.h> 21 #include <linux/iio/trigger_consumer.h> 22 #include <linux/iio/triggered_buffer.h> 23 #include <linux/iio/buffer.h> 24 25 #include <linux/platform_data/st_sensors_pdata.h> 26 27 #include "hts221.h" 28 29 #define HTS221_REG_DRDY_HL_ADDR 0x22 30 #define HTS221_REG_DRDY_HL_MASK BIT(7) 31 #define HTS221_REG_DRDY_PP_OD_ADDR 0x22 32 #define HTS221_REG_DRDY_PP_OD_MASK BIT(6) 33 #define HTS221_REG_DRDY_EN_ADDR 0x22 34 #define HTS221_REG_DRDY_EN_MASK BIT(2) 35 #define HTS221_REG_STATUS_ADDR 0x27 36 #define HTS221_RH_DRDY_MASK BIT(1) 37 #define HTS221_TEMP_DRDY_MASK BIT(0) 38 39 static int hts221_trig_set_state(struct iio_trigger *trig, bool state) 40 { 41 struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig); 42 struct hts221_hw *hw = iio_priv(iio_dev); 43 44 return regmap_update_bits(hw->regmap, HTS221_REG_DRDY_EN_ADDR, 45 HTS221_REG_DRDY_EN_MASK, 46 FIELD_PREP(HTS221_REG_DRDY_EN_MASK, state)); 47 } 48 49 static const struct iio_trigger_ops hts221_trigger_ops = { 50 .set_trigger_state = hts221_trig_set_state, 51 }; 52 53 static irqreturn_t hts221_trigger_handler_thread(int irq, void *private) 54 { 55 struct hts221_hw *hw = private; 56 int err, status; 57 58 err = regmap_read(hw->regmap, HTS221_REG_STATUS_ADDR, &status); 59 if (err < 0) 60 return IRQ_HANDLED; 61 62 /* 63 * H_DA bit (humidity data available) is routed to DRDY line. 64 * Humidity sample is computed after temperature one. 65 * Here we can assume data channels are both available if H_DA bit 66 * is set in status register 67 */ 68 if (!(status & HTS221_RH_DRDY_MASK)) 69 return IRQ_NONE; 70 71 iio_trigger_poll_nested(hw->trig); 72 73 return IRQ_HANDLED; 74 } 75 76 int hts221_allocate_trigger(struct iio_dev *iio_dev) 77 { 78 struct hts221_hw *hw = iio_priv(iio_dev); 79 struct st_sensors_platform_data *pdata = dev_get_platdata(hw->dev); 80 bool irq_active_low = false, open_drain = false; 81 unsigned long irq_type; 82 int err; 83 84 irq_type = irq_get_trigger_type(hw->irq); 85 switch (irq_type) { 86 case IRQF_TRIGGER_HIGH: 87 case IRQF_TRIGGER_RISING: 88 break; 89 case IRQF_TRIGGER_LOW: 90 case IRQF_TRIGGER_FALLING: 91 irq_active_low = true; 92 break; 93 default: 94 dev_info(hw->dev, 95 "mode %lx unsupported, using IRQF_TRIGGER_RISING\n", 96 irq_type); 97 irq_type = IRQF_TRIGGER_RISING; 98 break; 99 } 100 101 err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_HL_ADDR, 102 HTS221_REG_DRDY_HL_MASK, 103 FIELD_PREP(HTS221_REG_DRDY_HL_MASK, 104 irq_active_low)); 105 if (err < 0) 106 return err; 107 108 if (device_property_read_bool(hw->dev, "drive-open-drain") || 109 (pdata && pdata->open_drain)) { 110 irq_type |= IRQF_SHARED; 111 open_drain = true; 112 } 113 114 err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_PP_OD_ADDR, 115 HTS221_REG_DRDY_PP_OD_MASK, 116 FIELD_PREP(HTS221_REG_DRDY_PP_OD_MASK, 117 open_drain)); 118 if (err < 0) 119 return err; 120 121 err = devm_request_threaded_irq(hw->dev, hw->irq, NULL, 122 hts221_trigger_handler_thread, 123 irq_type | IRQF_ONESHOT, 124 hw->name, hw); 125 if (err) 126 return err; 127 128 hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger", 129 iio_dev->name); 130 if (!hw->trig) 131 return -ENOMEM; 132 133 iio_trigger_set_drvdata(hw->trig, iio_dev); 134 hw->trig->ops = &hts221_trigger_ops; 135 136 err = devm_iio_trigger_register(hw->dev, hw->trig); 137 138 iio_dev->trig = iio_trigger_get(hw->trig); 139 140 return err; 141 } 142 143 static int hts221_buffer_preenable(struct iio_dev *iio_dev) 144 { 145 return hts221_set_enable(iio_priv(iio_dev), true); 146 } 147 148 static int hts221_buffer_postdisable(struct iio_dev *iio_dev) 149 { 150 return hts221_set_enable(iio_priv(iio_dev), false); 151 } 152 153 static const struct iio_buffer_setup_ops hts221_buffer_ops = { 154 .preenable = hts221_buffer_preenable, 155 .postdisable = hts221_buffer_postdisable, 156 }; 157 158 static irqreturn_t hts221_buffer_handler_thread(int irq, void *p) 159 { 160 struct iio_poll_func *pf = p; 161 struct iio_dev *iio_dev = pf->indio_dev; 162 struct hts221_hw *hw = iio_priv(iio_dev); 163 struct iio_chan_spec const *ch; 164 int err; 165 166 /* humidity data */ 167 ch = &iio_dev->channels[HTS221_SENSOR_H]; 168 err = regmap_bulk_read(hw->regmap, ch->address, 169 &hw->scan.channels[0], 170 sizeof(hw->scan.channels[0])); 171 if (err < 0) 172 goto out; 173 174 /* temperature data */ 175 ch = &iio_dev->channels[HTS221_SENSOR_T]; 176 err = regmap_bulk_read(hw->regmap, ch->address, 177 &hw->scan.channels[1], 178 sizeof(hw->scan.channels[1])); 179 if (err < 0) 180 goto out; 181 182 iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, 183 iio_get_time_ns(iio_dev)); 184 185 out: 186 iio_trigger_notify_done(hw->trig); 187 188 return IRQ_HANDLED; 189 } 190 191 int hts221_allocate_buffers(struct iio_dev *iio_dev) 192 { 193 struct hts221_hw *hw = iio_priv(iio_dev); 194 return devm_iio_triggered_buffer_setup(hw->dev, iio_dev, 195 NULL, hts221_buffer_handler_thread, 196 &hts221_buffer_ops); 197 } 198 199 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>"); 200 MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver"); 201 MODULE_LICENSE("GPL v2"); 202