diff options
| -rw-r--r-- | Documentation/input/rotary-encoder.txt | 9 | ||||
| -rw-r--r-- | drivers/input/misc/rotary_encoder.c | 61 | ||||
| -rw-r--r-- | include/linux/rotary_encoder.h | 2 |
3 files changed, 51 insertions, 21 deletions
diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt index 435102a26d96..3a6aec40c0b0 100644 --- a/Documentation/input/rotary-encoder.txt +++ b/Documentation/input/rotary-encoder.txt @@ -67,7 +67,12 @@ data with it. struct rotary_encoder_platform_data is declared in include/linux/rotary-encoder.h and needs to be filled with the number of steps the encoder has and can carry information about externally inverted -signals (because of used invertig buffer or other reasons). +signals (because of an inverting buffer or other reasons). The encoder +can be set up to deliver input information as either an absolute or relative +axes. For relative axes the input event returns +/-1 for each step. For +absolute axes the position of the encoder can either roll over between zero +and the number of steps or will clamp at the maximum and zero depending on +the configuration. Because GPIO to IRQ mapping is platform specific, this information must be given in seperately to the driver. See the example below. @@ -85,6 +90,8 @@ be given in seperately to the driver. See the example below. static struct rotary_encoder_platform_data my_rotary_encoder_info = { .steps = 24, .axis = ABS_X, + .relative_axis = false, + .rollover = false, .gpio_a = GPIO_ROTARY_A, .gpio_b = GPIO_ROTARY_B, .inverted_a = 0, diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 5bb3ab51b8c6..c806fbf1e174 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -26,13 +26,17 @@ #define DRV_NAME "rotary-encoder" struct rotary_encoder { - unsigned int irq_a; - unsigned int irq_b; - unsigned int pos; - unsigned int armed; - unsigned int dir; struct input_dev *input; struct rotary_encoder_platform_data *pdata; + + unsigned int axis; + unsigned int pos; + + unsigned int irq_a; + unsigned int irq_b; + + bool armed; + unsigned char dir; /* 0 - clockwise, 1 - CCW */ }; static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) @@ -53,21 +57,32 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) if (!encoder->armed) break; - if (encoder->dir) { - /* turning counter-clockwise */ - encoder->pos += pdata->steps; - encoder->pos--; - encoder->pos %= pdata->steps; + if (pdata->relative_axis) { + input_report_rel(encoder->input, pdata->axis, + encoder->dir ? -1 : 1); } else { - /* turning clockwise */ - encoder->pos++; - encoder->pos %= pdata->steps; + unsigned int pos = encoder->pos; + + if (encoder->dir) { + /* turning counter-clockwise */ + if (pdata->rollover) + pos += pdata->steps; + if (pos) + pos--; + } else { + /* turning clockwise */ + if (pdata->rollover || pos < pdata->steps) + pos++; + } + if (pdata->rollover) + pos %= pdata->steps; + encoder->pos = pos; + input_report_abs(encoder->input, pdata->axis, + encoder->pos); } - - input_report_abs(encoder->input, pdata->axis, encoder->pos); input_sync(encoder->input); - encoder->armed = 0; + encoder->armed = false; break; case 0x1: @@ -77,7 +92,7 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) break; case 0x3: - encoder->armed = 1; + encoder->armed = true; break; } @@ -113,9 +128,15 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) input->name = pdev->name; input->id.bustype = BUS_HOST; input->dev.parent = &pdev->dev; - input->evbit[0] = BIT_MASK(EV_ABS); - input_set_abs_params(encoder->input, - pdata->axis, 0, pdata->steps, 0, 1); + + if (pdata->relative_axis) { + input->evbit[0] = BIT_MASK(EV_REL); + input->relbit[0] = BIT_MASK(pdata->axis); + } else { + input->evbit[0] = BIT_MASK(EV_ABS); + input_set_abs_params(encoder->input, + pdata->axis, 0, pdata->steps, 0, 1); + } err = input_register_device(input); if (err) { diff --git a/include/linux/rotary_encoder.h b/include/linux/rotary_encoder.h index 12d63a30c347..215278b8df2a 100644 --- a/include/linux/rotary_encoder.h +++ b/include/linux/rotary_encoder.h @@ -8,6 +8,8 @@ struct rotary_encoder_platform_data { unsigned int gpio_b; unsigned int inverted_a; unsigned int inverted_b; + bool relative_axis; + bool rollover; }; #endif /* __ROTARY_ENCODER_H__ */ |
