[2/2] iio: ti_am335x_adc: Add continuous sampling support

Message ID	1379393047-11772-3-git-send-email-zubair.lutfullah@gmail.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-input-owner@kernel.org> From: Zubair Lutfullah <zubair.lutfullah@gmail.com> To: jic23@cam.ac.uk, dmitry.torokhov@gmail.com Cc: linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, gregkh@linuxfoundation.org, zubair.lutfullah@gmail.com Subject: [PATCH 2/2] iio: ti_am335x_adc: Add continuous sampling support Date: Tue, 17 Sep 2013 09:44:07 +0500 Message-Id: <1379393047-11772-3-git-send-email-zubair.lutfullah@gmail.com> In-Reply-To: <1379393047-11772-1-git-send-email-zubair.lutfullah@gmail.com> References: <1379393047-11772-1-git-send-email-zubair.lutfullah@gmail.com> Sender: linux-input-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index a952538..fa916f3 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -28,12 +28,19 @@ #include <linux/iio/driver.h> #include <linux/mfd/ti_am335x_tscadc.h> +#include <linux/iio/buffer.h> +#include <linux/iio/kfifo_buf.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> struct tiadc_device { struct ti_tscadc_dev *mfd_tscadc; int channels; u8 channel_line[8]; u8 channel_step[8]; + int buffer_en_ch_steps; + u32 *data; }; static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg) @@ -56,8 +63,14 @@ static u32 get_adc_step_mask(struct tiadc_device *adc_dev) return step_en; } -static void tiadc_step_config(struct tiadc_device *adc_dev) +static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan) { + return 1 << adc_dev->channel_step[chan]; +} + +static void tiadc_step_config(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); unsigned int stepconfig; int i, steps; @@ -72,7 +85,11 @@ static void tiadc_step_config(struct tiadc_device *adc_dev) */ steps = TOTAL_STEPS - adc_dev->channels; - stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1; + if (iio_buffer_enabled(indio_dev)) + stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1 + | STEPCONFIG_MODE_SWCNT; + else + stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1; for (i = 0; i < adc_dev->channels; i++) { int chan; @@ -85,7 +102,183 @@ static void tiadc_step_config(struct tiadc_device *adc_dev) adc_dev->channel_step[i] = steps; steps++; } +} + +static irqreturn_t tiadc_irq_h(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct tiadc_device *adc_dev = iio_priv(indio_dev); + unsigned int status, config; + status = tiadc_readl(adc_dev, REG_IRQSTATUS); + + /* + * ADC and touchscreen share the IRQ line. + * FIFO0 interrupts are used by TSC. Handle FIFO1 IRQs here only + */ + if (status & IRQENB_FIFO1OVRRUN) { + /* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */ + config = tiadc_readl(adc_dev, REG_CTRL); + config &= ~(CNTRLREG_TSCSSENB); + tiadc_writel(adc_dev, REG_CTRL, config); + tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN + | IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES); + tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB)); + return IRQ_HANDLED; + } else if (status & IRQENB_FIFO1THRES) { + /* Disable irq and wake worker thread */ + tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES); + return IRQ_WAKE_THREAD; + } + + return IRQ_NONE; +} + +static irqreturn_t tiadc_worker_h(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct tiadc_device *adc_dev = iio_priv(indio_dev); + int i, k, fifo1count, read; + u32 *data = adc_dev->data; + + fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); + for (k = 0; k < fifo1count; k = k + i) { + for (i = 0; i < (indio_dev->scan_bytes)/4; i++) { + read = tiadc_readl(adc_dev, REG_FIFO1); + data[i] = read & FIFOREAD_DATA_MASK; + } + iio_push_to_buffers(indio_dev, (u8 *) data); + } + + tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES); + tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES); + return IRQ_HANDLED; +} + +static int tiadc_buffer_preenable(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); + int i, fifo1count, read; + + tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | + IRQENB_FIFO1OVRRUN | + IRQENB_FIFO1UNDRFLW)); + + /* Flush FIFO. Needed in corner cases in simultaneous tsc/adc use */ + fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); + for (i = 0; i < fifo1count; i++) + read = tiadc_readl(adc_dev, REG_FIFO1); + + return iio_sw_buffer_preenable(indio_dev); +} + +static int tiadc_buffer_postenable(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); + struct iio_buffer *buffer = indio_dev->buffer; + unsigned int enb = 0; + u8 bit; + + adc_dev->data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL); + if (adc_dev->data == NULL) + return -ENOMEM; + + tiadc_step_config(indio_dev); + for_each_set_bit(bit, buffer->scan_mask, adc_dev->channels) + enb |= (get_adc_step_bit(adc_dev, bit) << 1); + adc_dev->buffer_en_ch_steps = enb; + + am335x_tsc_se_set(adc_dev->mfd_tscadc, enb); + + tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES + | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW); + tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES + | IRQENB_FIFO1OVRRUN); + + return 0; +} + +static int tiadc_buffer_predisable(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); + int fifo1count, i, read; + + tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | + IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW)); + am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps); + + /* Flush FIFO of leftover data in the time it takes to disable adc */ + fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); + for (i = 0; i < fifo1count; i++) + read = tiadc_readl(adc_dev, REG_FIFO1); + + return 0; +} + +static int tiadc_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); + + tiadc_step_config(indio_dev); + kfree(adc_dev->data); + + return 0; +} + +static const struct iio_buffer_setup_ops tiadc_buffer_setup_ops = { + .preenable = &tiadc_buffer_preenable, + .postenable = &tiadc_buffer_postenable, + .predisable = &tiadc_buffer_predisable, + .postdisable = &tiadc_buffer_postdisable, +}; + +int tiadc_iio_buffered_hardware_setup(struct iio_dev *indio_dev, + irqreturn_t (*pollfunc_bh)(int irq, void *p), + irqreturn_t (*pollfunc_th)(int irq, void *p), + int irq, + unsigned long flags, + const struct iio_buffer_setup_ops *setup_ops) +{ + int ret; + + indio_dev->buffer = iio_kfifo_allocate(indio_dev); + if (!indio_dev->buffer) + return -ENOMEM; + + ret = devm_request_threaded_irq(indio_dev->dev.parent, + irq, + pollfunc_th, pollfunc_bh, + flags, indio_dev->name, + indio_dev); + if (ret) + goto error_kfifo_free; + + indio_dev->setup_ops = setup_ops; + indio_dev->modes |= INDIO_BUFFER_HARDWARE; + + ret = iio_buffer_register(indio_dev, + indio_dev->channels, + indio_dev->num_channels); + if (ret) + goto error_free_irq; + + return 0; + +error_free_irq: + devm_free_irq(indio_dev->dev.parent, irq, indio_dev); +error_kfifo_free: + iio_kfifo_free(indio_dev->buffer); + return ret; +} + +static void tiadc_iio_buffered_hardware_remove(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); + + devm_free_irq(indio_dev->dev.parent, + adc_dev->mfd_tscadc->irq, indio_dev); + iio_kfifo_free(indio_dev->buffer); + iio_buffer_unregister(indio_dev); } static const char * const chan_name_ain[] = { @@ -120,6 +313,7 @@ static int tiadc_channel_init(struct iio_dev *indio_dev, int channels) chan->channel = adc_dev->channel_line[i]; chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); chan->datasheet_name = chan_name_ain[chan->channel]; + chan->scan_index = i; chan->scan_type.sign = 'u'; chan->scan_type.realbits = 12; chan->scan_type.storagebits = 32; @@ -147,6 +341,10 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, u32 step_en; unsigned long timeout = jiffies + usecs_to_jiffies (IDLE_TIMEOUT * adc_dev->channels); + + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + step_en = get_adc_step_mask(adc_dev); am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en); @@ -237,20 +435,33 @@ static int tiadc_probe(struct platform_device *pdev) indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &tiadc_info; - tiadc_step_config(adc_dev); + tiadc_step_config(indio_dev); + tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD); err = tiadc_channel_init(indio_dev, adc_dev->channels); if (err < 0) return err; - err = iio_device_register(indio_dev); + err = tiadc_iio_buffered_hardware_setup(indio_dev, + &tiadc_worker_h, + &tiadc_irq_h, + adc_dev->mfd_tscadc->irq, + IRQF_SHARED, + &tiadc_buffer_setup_ops); + if (err) goto err_free_channels; + err = iio_device_register(indio_dev); + if (err) + goto err_buffer_unregister; + platform_set_drvdata(pdev, indio_dev); return 0; +err_buffer_unregister: + tiadc_iio_buffered_hardware_remove(indio_dev); err_free_channels: tiadc_channels_remove(indio_dev); return err; @@ -263,6 +474,7 @@ static int tiadc_remove(struct platform_device *pdev) u32 step_en; iio_device_unregister(indio_dev); + tiadc_iio_buffered_hardware_remove(indio_dev); tiadc_channels_remove(indio_dev); step_en = get_adc_step_mask(adc_dev); @@ -301,7 +513,7 @@ static int tiadc_resume(struct device *dev) restore &= ~(CNTRLREG_POWERDOWN); tiadc_writel(adc_dev, REG_CTRL, restore); - tiadc_step_config(adc_dev); + tiadc_step_config(indio_dev); return 0; } diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index db1791b..7d98562 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -46,16 +46,24 @@ /* Step Enable */ #define STEPENB_MASK (0x1FFFF << 0) #define STEPENB(val) ((val) << 0) +#define ENB(val) (1 << (val)) +#define STPENB_STEPENB STEPENB(0x1FFFF) +#define STPENB_STEPENB_TC STEPENB(0x1FFF) /* IRQ enable */ #define IRQENB_HW_PEN BIT(0) #define IRQENB_FIFO0THRES BIT(2) +#define IRQENB_FIFO0OVRRUN BIT(3) +#define IRQENB_FIFO0UNDRFLW BIT(4) #define IRQENB_FIFO1THRES BIT(5) +#define IRQENB_FIFO1OVRRUN BIT(6) +#define IRQENB_FIFO1UNDRFLW BIT(7) #define IRQENB_PENUP BIT(9) /* Step Configuration */ #define STEPCONFIG_MODE_MASK (3 << 0) #define STEPCONFIG_MODE(val) ((val) << 0) +#define STEPCONFIG_MODE_SWCNT STEPCONFIG_MODE(1) #define STEPCONFIG_MODE_HWSYNC STEPCONFIG_MODE(2) #define STEPCONFIG_AVG_MASK (7 << 2) #define STEPCONFIG_AVG(val) ((val) << 2) @@ -124,6 +132,7 @@ #define MAX_CLK_DIV 7 #define TOTAL_STEPS 16 #define TOTAL_CHANNELS 8 +#define FIFO1_THRESHOLD 19 /* * ADC runs at 3MHz, and it takes

[2/2] iio: ti_am335x_adc: Add continuous sampling support

Commit Message

Comments

Patch