From bc93aa7640fe97df8d69b50fdce70da1126e12b3 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Sat, 6 Jul 2013 05:20:00 +0100 Subject: iio: ti_am335x_adc: add missing .driver_module to struct iio_info Add missing .driver_module of struct iio_info. This prevents the module from being removed from underneath its users. Signed-off-by: Wei Yongjun Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ti_am335x_adc.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/iio/adc/ti_am335x_adc.c') diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index 5f9a7e7d3135..985f58873d03 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -134,6 +134,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, static const struct iio_info tiadc_info = { .read_raw = &tiadc_read_raw, + .driver_module = THIS_MODULE, }; static int tiadc_probe(struct platform_device *pdev) -- cgit v1.2.3 From b1451e546899bc8f450773b2af02e0cd000cf1fa Mon Sep 17 00:00:00 2001 From: "Patil, Rachna" Date: Sat, 20 Jul 2013 17:27:00 +0100 Subject: iio: ti_am335x_adc: Fix wrong samples received on 1st read Previously we tried to read data form ADC even before ADC sequencer finished sampling. This led to wrong samples. We now wait on ADC status register idle bit to be set. Signed-off-by: Patil, Rachna Signed-off-by: Zubair Lutfullah Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ti_am335x_adc.c | 30 ++++++++++++++++++++++-------- include/linux/mfd/ti_am335x_tscadc.h | 16 ++++++++++++++++ 2 files changed, 38 insertions(+), 8 deletions(-) (limited to 'drivers/iio/adc/ti_am335x_adc.c') diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index 0ad208a69c29..3ceac3e91dde 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -60,7 +60,6 @@ static void tiadc_step_config(struct tiadc_device *adc_dev) { unsigned int stepconfig; int i, steps; - u32 step_en; /* * There are 16 configurable steps and 8 analog input @@ -86,8 +85,7 @@ static void tiadc_step_config(struct tiadc_device *adc_dev) adc_dev->channel_step[i] = steps; steps++; } - step_en = get_adc_step_mask(adc_dev); - am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en); + } static const char * const chan_name_ain[] = { @@ -142,10 +140,22 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct tiadc_device *adc_dev = iio_priv(indio_dev); - int i; - unsigned int fifo1count, read; + int i, map_val; + unsigned int fifo1count, read, stepid; u32 step = UINT_MAX; bool found = false; + u32 step_en; + unsigned long timeout = jiffies + usecs_to_jiffies + (IDLE_TIMEOUT * adc_dev->channels); + step_en = get_adc_step_mask(adc_dev); + am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en); + + /* Wait for ADC sequencer to complete sampling */ + while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) { + if (time_after(jiffies, timeout)) + return -EAGAIN; + } + map_val = chan->channel + TOTAL_CHANNELS; /* * When the sub-system is first enabled, @@ -170,12 +180,16 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); for (i = 0; i < fifo1count; i++) { read = tiadc_readl(adc_dev, REG_FIFO1); - if (read >> 16 == step) { - *val = read & 0xfff; + stepid = read & FIFOREAD_CHNLID_MASK; + stepid = stepid >> 0x10; + + if (stepid == map_val) { + read = read & FIFOREAD_DATA_MASK; found = true; + *val = read; } } - am335x_tsc_se_update(adc_dev->mfd_tscadc); + if (found == false) return -EBUSY; return IIO_VAL_INT; diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index 8d73fe29796a..db1791bb997a 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -113,11 +113,27 @@ #define CNTRLREG_8WIRE CNTRLREG_AFE_CTRL(3) #define CNTRLREG_TSCENB BIT(7) +/* FIFO READ Register */ +#define FIFOREAD_DATA_MASK (0xfff << 0) +#define FIFOREAD_CHNLID_MASK (0xf << 16) + +/* Sequencer Status */ +#define SEQ_STATUS BIT(5) + #define ADC_CLK 3000000 #define MAX_CLK_DIV 7 #define TOTAL_STEPS 16 #define TOTAL_CHANNELS 8 +/* +* ADC runs at 3MHz, and it takes +* 15 cycles to latch one data output. +* Hence the idle time for ADC to +* process one sample data would be +* around 5 micro seconds. +*/ +#define IDLE_TIMEOUT 5 /* microsec */ + #define TSCADC_CELLS 2 struct ti_tscadc_dev { -- cgit v1.2.3