diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2008-11-08 01:10:21 +0100 |
|---|---|---|
| committer | Samuel Ortiz <samuel@sortiz.org> | 2009-01-04 12:17:38 +0100 |
| commit | 67488526349d043372d141c054f4dc6313780b3c (patch) | |
| tree | 22db1f6609edd7945fb000b4a9c48e86aadf3dfb /drivers | |
| parent | 0c8a601678960fbcc1c1185a283d6d107575810b (diff) | |
mfd: Add AUXADC support for WM8350
The auxiliary ADC in the WM8350 is shared between several subdevices
so access to it needs to be arbitrated by the core driver.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mfd/wm8350-core.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c index c013afde260..60439bd3984 100644 --- a/drivers/mfd/wm8350-core.c +++ b/drivers/mfd/wm8350-core.c @@ -63,7 +63,6 @@ */ static DEFINE_MUTEX(io_mutex); static DEFINE_MUTEX(reg_lock_mutex); -static DEFINE_MUTEX(auxadc_mutex); /* Perform a physical read from the device. */ @@ -1082,6 +1081,55 @@ int wm8350_unmask_irq(struct wm8350 *wm8350, int irq) } EXPORT_SYMBOL_GPL(wm8350_unmask_irq); +int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref) +{ + u16 reg, result = 0; + int tries = 5; + + if (channel < WM8350_AUXADC_AUX1 || channel > WM8350_AUXADC_TEMP) + return -EINVAL; + if (channel >= WM8350_AUXADC_USB && channel <= WM8350_AUXADC_TEMP + && (scale != 0 || vref != 0)) + return -EINVAL; + + mutex_lock(&wm8350->auxadc_mutex); + + /* Turn on the ADC */ + reg = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5); + wm8350_reg_write(wm8350, WM8350_POWER_MGMT_5, reg | WM8350_AUXADC_ENA); + + if (scale || vref) { + reg = scale << 13; + reg |= vref << 12; + wm8350_reg_write(wm8350, WM8350_AUX1_READBACK + channel, reg); + } + + reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1); + reg |= 1 << channel | WM8350_AUXADC_POLL; + wm8350_reg_write(wm8350, WM8350_DIGITISER_CONTROL_1, reg); + + do { + schedule_timeout_interruptible(1); + reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1); + } while (tries-- && (reg & WM8350_AUXADC_POLL)); + + if (!tries) + dev_err(wm8350->dev, "adc chn %d read timeout\n", channel); + else + result = wm8350_reg_read(wm8350, + WM8350_AUX1_READBACK + channel); + + /* Turn off the ADC */ + reg = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5); + wm8350_reg_write(wm8350, WM8350_POWER_MGMT_5, + reg & ~WM8350_AUXADC_ENA); + + mutex_unlock(&wm8350->auxadc_mutex); + + return result & WM8350_AUXADC_DATA1_MASK; +} +EXPORT_SYMBOL_GPL(wm8350_read_auxadc); + /* * Cache is always host endian. */ @@ -1239,6 +1287,7 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq, } } + mutex_init(&wm8350->auxadc_mutex); mutex_init(&wm8350->irq_mutex); INIT_WORK(&wm8350->irq_work, wm8350_irq_worker); if (irq) { |