diff options
Diffstat (limited to 'drivers/iio/adc/at91-sama5d2_adc.c')
| -rw-r--r-- | drivers/iio/adc/at91-sama5d2_adc.c | 256 |
1 files changed, 144 insertions, 112 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 9d96f7d08b95..de9583d6cddd 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -8,6 +8,7 @@ #include <linux/bitops.h> #include <linux/clk.h> +#include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/interrupt.h> @@ -100,6 +101,8 @@ #define AT91_SAMA5D2_IER_YRDY BIT(21) /* Interrupt Enable Register - TS pressure measurement ready */ #define AT91_SAMA5D2_IER_PRDY BIT(22) +/* Interrupt Enable Register - Data ready */ +#define AT91_SAMA5D2_IER_DRDY BIT(24) /* Interrupt Enable Register - general overrun error */ #define AT91_SAMA5D2_IER_GOVRE BIT(25) /* Interrupt Enable Register - Pen detect */ @@ -344,7 +347,7 @@ struct at91_adc_trigger { }; /** - * at91_adc_dma - at91-sama5d2 dma information struct + * struct at91_adc_dma - at91-sama5d2 dma information struct * @dma_chan: the dma channel acquired * @rx_buf: dma coherent allocated area * @rx_dma_buf: dma handler for the buffer @@ -366,7 +369,7 @@ struct at91_adc_dma { }; /** - * at91_adc_touch - at91-sama5d2 touchscreen information struct + * struct at91_adc_touch - at91-sama5d2 touchscreen information struct * @sample_period_val: the value for periodic trigger interval * @touching: is the pen touching the screen or not * @x_pos: temporary placeholder for pressure computation @@ -399,6 +402,7 @@ struct at91_adc_state { wait_queue_head_t wq_data_available; struct at91_adc_dma dma_st; struct at91_adc_touch touch_st; + struct iio_dev *indio_dev; u16 buffer[AT91_BUFFER_MAX_HWORDS]; /* * lock to prevent concurrent 'single conversion' requests through @@ -486,6 +490,21 @@ static inline int at91_adc_of_xlate(struct iio_dev *indio_dev, return at91_adc_chan_xlate(indio_dev, iiospec->args[0]); } +static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev) +{ + u32 mask = 0; + u8 bit; + + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + mask |= BIT(chan->channel); + } + + return mask & GENMASK(11, 0); +} + static void at91_adc_config_emr(struct at91_adc_state *st) { /* configure the extended mode register */ @@ -624,13 +643,13 @@ static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg) /* first half of register is the x or y, second half is the scale */ val = at91_adc_readl(st, reg); if (!val) - dev_dbg(&iio_priv_to_dev(st)->dev, "pos is 0\n"); + dev_dbg(&st->indio_dev->dev, "pos is 0\n"); pos = val & AT91_SAMA5D2_XYZ_MASK; result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos; scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK; if (scale == 0) { - dev_err(&iio_priv_to_dev(st)->dev, "scale is 0\n"); + dev_err(&st->indio_dev->dev, "scale is 0\n"); return 0; } result /= scale; @@ -710,7 +729,6 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) struct iio_dev *indio = iio_trigger_get_drvdata(trig); struct at91_adc_state *st = iio_priv(indio); u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR); - u8 bit; /* clear TRGMOD */ status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK; @@ -721,50 +739,6 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) /* set/unset hw trigger */ at91_adc_writel(st, AT91_SAMA5D2_TRGR, status); - for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) { - struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit); - u32 cor; - - if (!chan) - continue; - /* these channel types cannot be handled by this trigger */ - if (chan->type == IIO_POSITIONRELATIVE || - chan->type == IIO_PRESSURE) - continue; - - if (state) { - cor = at91_adc_readl(st, AT91_SAMA5D2_COR); - - if (chan->differential) - cor |= (BIT(chan->channel) | - BIT(chan->channel2)) << - AT91_SAMA5D2_COR_DIFF_OFFSET; - else - cor &= ~(BIT(chan->channel) << - AT91_SAMA5D2_COR_DIFF_OFFSET); - - at91_adc_writel(st, AT91_SAMA5D2_COR, cor); - } - - if (state) { - at91_adc_writel(st, AT91_SAMA5D2_CHER, - BIT(chan->channel)); - /* enable irq only if not using DMA */ - if (!st->dma_st.dma_chan) { - at91_adc_writel(st, AT91_SAMA5D2_IER, - BIT(chan->channel)); - } - } else { - /* disable irq only if not using DMA */ - if (!st->dma_st.dma_chan) { - at91_adc_writel(st, AT91_SAMA5D2_IDR, - BIT(chan->channel)); - } - at91_adc_writel(st, AT91_SAMA5D2_CHDR, - BIT(chan->channel)); - } - } - return 0; } @@ -781,6 +755,7 @@ static int at91_adc_reenable_trigger(struct iio_trigger *trig) /* Needed to ACK the DRDY interruption */ at91_adc_readl(st, AT91_SAMA5D2_LCDR); + return 0; } @@ -888,18 +863,37 @@ static int at91_adc_dma_start(struct iio_dev *indio_dev) return 0; } -static int at91_adc_buffer_postenable(struct iio_dev *indio_dev) +static bool at91_adc_buffer_check_use_irq(struct iio_dev *indio, + struct at91_adc_state *st) +{ + /* if using DMA, we do not use our own IRQ (we use DMA-controller) */ + if (st->dma_st.dma_chan) + return false; + /* if the trigger is not ours, then it has its own IRQ */ + if (iio_trigger_validate_own_device(indio->trig, indio)) + return false; + return true; +} + +static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + return !!bitmap_subset(indio_dev->active_scan_mask, + &st->touch_st.channels_bitmask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1); +} + +static int at91_adc_buffer_preenable(struct iio_dev *indio_dev) { int ret; + u8 bit; struct at91_adc_state *st = iio_priv(indio_dev); /* check if we are enabling triggered buffer or the touchscreen */ - if (bitmap_subset(indio_dev->active_scan_mask, - &st->touch_st.channels_bitmask, - AT91_SAMA5D2_MAX_CHAN_IDX + 1)) { - /* touchscreen enabling */ + if (at91_adc_current_chan_is_touch(indio_dev)) return at91_adc_configure_touch(st, true); - } + /* if we are not in triggered mode, we cannot enable the buffer. */ if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES)) return -EINVAL; @@ -911,41 +905,57 @@ static int at91_adc_buffer_postenable(struct iio_dev *indio_dev) return ret; } - return iio_triggered_buffer_postenable(indio_dev); + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + u32 cor; + + if (!chan) + continue; + /* these channel types cannot be handled by this trigger */ + if (chan->type == IIO_POSITIONRELATIVE || + chan->type == IIO_PRESSURE) + continue; + + cor = at91_adc_readl(st, AT91_SAMA5D2_COR); + + if (chan->differential) + cor |= (BIT(chan->channel) | BIT(chan->channel2)) << + AT91_SAMA5D2_COR_DIFF_OFFSET; + else + cor &= ~(BIT(chan->channel) << + AT91_SAMA5D2_COR_DIFF_OFFSET); + + at91_adc_writel(st, AT91_SAMA5D2_COR, cor); + + at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel)); + } + + if (at91_adc_buffer_check_use_irq(indio_dev, st)) + at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_DRDY); + + return 0; } -static int at91_adc_buffer_predisable(struct iio_dev *indio_dev) +static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev) { struct at91_adc_state *st = iio_priv(indio_dev); - int ret; u8 bit; /* check if we are disabling triggered buffer or the touchscreen */ - if (bitmap_subset(indio_dev->active_scan_mask, - &st->touch_st.channels_bitmask, - AT91_SAMA5D2_MAX_CHAN_IDX + 1)) { - /* touchscreen disable */ + if (at91_adc_current_chan_is_touch(indio_dev)) return at91_adc_configure_touch(st, false); - } + /* if we are not in triggered mode, nothing to do here */ if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES)) return -EINVAL; - /* continue with the triggered buffer */ - ret = iio_triggered_buffer_predisable(indio_dev); - if (ret < 0) - dev_err(&indio_dev->dev, "buffer predisable failed\n"); - - if (!st->dma_st.dma_chan) - return ret; - - /* if we are using DMA we must clear registers and end DMA */ - dmaengine_terminate_sync(st->dma_st.dma_chan); - /* - * For each enabled channel we must read the last converted value + * For each enable channel we must disable it in hardware. + * In the case of DMA, we must read the last converted value * to clear EOC status and not get a possible interrupt later. - * This value is being read by DMA from LCDR anyway + * This value is being read by DMA from LCDR anyway, so it's not lost. */ for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->num_channels) { @@ -958,18 +968,29 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev) if (chan->type == IIO_POSITIONRELATIVE || chan->type == IIO_PRESSURE) continue; + + at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel)); + if (st->dma_st.dma_chan) at91_adc_readl(st, chan->address); } + if (at91_adc_buffer_check_use_irq(indio_dev, st)) + at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_DRDY); + /* read overflow register to clear possible overflow status */ at91_adc_readl(st, AT91_SAMA5D2_OVER); - return ret; + + /* if we are using DMA we must clear registers and end DMA */ + if (st->dma_st.dma_chan) + dmaengine_terminate_sync(st->dma_st.dma_chan); + + return 0; } static const struct iio_buffer_setup_ops at91_buffer_setup_ops = { - .postenable = &at91_adc_buffer_postenable, - .predisable = &at91_adc_buffer_predisable, + .preenable = &at91_adc_buffer_preenable, + .postdisable = &at91_adc_buffer_postdisable, }; static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio, @@ -1015,6 +1036,22 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev, int i = 0; int val; u8 bit; + u32 mask = at91_adc_active_scan_mask_to_reg(indio_dev); + unsigned int timeout = 50; + + /* + * Check if the conversion is ready. If not, wait a little bit, and + * in case of timeout exit with an error. + */ + while ((at91_adc_readl(st, AT91_SAMA5D2_ISR) & mask) != mask && + timeout) { + usleep_range(50, 100); + timeout--; + } + + /* Cannot read data, not ready. Continue without reporting data */ + if (!timeout) + return; for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->num_channels) { @@ -1102,6 +1139,13 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) struct iio_dev *indio_dev = pf->indio_dev; struct at91_adc_state *st = iio_priv(indio_dev); + /* + * If it's not our trigger, start a conversion now, as we are + * actually polling the trigger now. + */ + if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev)) + at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START); + if (st->dma_st.dma_chan) at91_adc_trigger_handler_dma(indio_dev); else @@ -1114,20 +1158,9 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) static int at91_adc_buffer_init(struct iio_dev *indio) { - struct at91_adc_state *st = iio_priv(indio); - - if (st->selected_trig->hw_trig) { - return devm_iio_triggered_buffer_setup(&indio->dev, indio, - &iio_pollfunc_store_time, - &at91_adc_trigger_handler, &at91_buffer_setup_ops); - } - /* - * we need to prepare the buffer ops in case we will get - * another buffer attached (like a callback buffer for the touchscreen) - */ - indio->setup_ops = &at91_buffer_setup_ops; - - return 0; + return devm_iio_triggered_buffer_setup(&indio->dev, indio, + &iio_pollfunc_store_time, + &at91_adc_trigger_handler, &at91_buffer_setup_ops); } static unsigned at91_adc_startup_time(unsigned startup_time_min, @@ -1154,9 +1187,9 @@ static unsigned at91_adc_startup_time(unsigned startup_time_min, return i; } -static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq) +static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq) { - struct iio_dev *indio_dev = iio_priv_to_dev(st); + struct at91_adc_state *st = iio_priv(indio_dev); unsigned f_per, prescal, startup, mr; f_per = clk_get_rate(st->per_clk); @@ -1225,9 +1258,9 @@ static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st) st->touch_st.touching = true; } -static void at91_adc_no_pen_detect_interrupt(struct at91_adc_state *st) +static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev) { - struct iio_dev *indio_dev = iio_priv_to_dev(st); + struct at91_adc_state *st = iio_priv(indio_dev); at91_adc_writel(st, AT91_SAMA5D2_TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER); @@ -1247,7 +1280,7 @@ static void at91_adc_workq_handler(struct work_struct *workq) struct at91_adc_touch, workq); struct at91_adc_state *st = container_of(touch_st, struct at91_adc_state, touch_st); - struct iio_dev *indio_dev = iio_priv_to_dev(st); + struct iio_dev *indio_dev = st->indio_dev; iio_push_to_buffers(indio_dev, st->buffer); } @@ -1268,7 +1301,7 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private) at91_adc_pen_detect_interrupt(st); } else if ((status & AT91_SAMA5D2_IER_NOPEN)) { /* nopen detected IRQ */ - at91_adc_no_pen_detect_interrupt(st); + at91_adc_no_pen_detect_interrupt(indio); } else if ((status & AT91_SAMA5D2_ISR_PENS) && ((status & rdy_mask) == rdy_mask)) { /* periodic trigger IRQ - during pen sense */ @@ -1281,7 +1314,8 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private) status = at91_adc_readl(st, AT91_SAMA5D2_XPOSR); status = at91_adc_readl(st, AT91_SAMA5D2_YPOSR); status = at91_adc_readl(st, AT91_SAMA5D2_PRESSR); - } else if (iio_buffer_enabled(indio) && !st->dma_st.dma_chan) { + } else if (iio_buffer_enabled(indio) && + (status & AT91_SAMA5D2_IER_DRDY)) { /* triggered buffer without DMA */ disable_irq_nosync(irq); iio_trigger_poll(indio->trig); @@ -1435,7 +1469,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, val > st->soc_info.max_sample_rate) return -EINVAL; - at91_adc_setup_samp_freq(st, val); + at91_adc_setup_samp_freq(indio_dev, val); return 0; default: return -EINVAL; @@ -1573,8 +1607,10 @@ static int at91_adc_update_scan_mode(struct iio_dev *indio_dev, return 0; } -static void at91_adc_hw_init(struct at91_adc_state *st) +static void at91_adc_hw_init(struct iio_dev *indio_dev) { + struct at91_adc_state *st = iio_priv(indio_dev); + at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST); at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff); /* @@ -1584,7 +1620,7 @@ static void at91_adc_hw_init(struct at91_adc_state *st) at91_adc_writel(st, AT91_SAMA5D2_MR, AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH); - at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate); + at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate); /* configure extended mode register */ at91_adc_config_emr(st); @@ -1659,7 +1695,6 @@ static int at91_adc_probe(struct platform_device *pdev) if (!indio_dev) return -ENOMEM; - indio_dev->dev.parent = &pdev->dev; indio_dev->name = dev_name(&pdev->dev); indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; indio_dev->info = &at91_adc_info; @@ -1667,6 +1702,7 @@ static int at91_adc_probe(struct platform_device *pdev) indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels); st = iio_priv(indio_dev); + st->indio_dev = indio_dev; bitmap_set(&st->touch_st.channels_bitmask, AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 1); @@ -1778,7 +1814,7 @@ static int at91_adc_probe(struct platform_device *pdev) goto vref_disable; } - at91_adc_hw_init(st); + at91_adc_hw_init(indio_dev); ret = clk_prepare_enable(st->per_clk); if (ret) @@ -1894,21 +1930,17 @@ static __maybe_unused int at91_adc_resume(struct device *dev) if (ret) goto vref_disable_resume; - at91_adc_hw_init(st); + at91_adc_hw_init(indio_dev); /* reconfiguring trigger hardware state */ if (!iio_buffer_enabled(indio_dev)) return 0; /* check if we are enabling triggered buffer or the touchscreen */ - if (bitmap_subset(indio_dev->active_scan_mask, - &st->touch_st.channels_bitmask, - AT91_SAMA5D2_MAX_CHAN_IDX + 1)) { - /* touchscreen enabling */ + if (at91_adc_current_chan_is_touch(indio_dev)) return at91_adc_configure_touch(st, true); - } else { + else return at91_adc_configure_trigger(st->trig, true); - } /* not needed but more explicit */ return 0; |