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| author | Clemens Ladisch <clemens@ladisch.de> | 2008-09-22 11:04:43 +0400 |
|---|---|---|
| committer | Clemens Ladisch <clemens@ladisch.de> | 2008-09-22 11:04:43 +0400 |
| commit | 397b1dcc449082ce3f720c548da9c59db01cb739 (patch) | |
| tree | a5295eabb214f913cd931c50b079c81b8086e577 /sound/pci/oxygen/oxygen_lib.c | |
| parent | dbbbd6744439d95d2b0dc23c5cdca2c477377f76 (diff) | |
| download | linux-397b1dcc449082ce3f720c548da9c59db01cb739.tar.xz | |
ALSA: oxygen: add UART I/O functions
Add functions to allow model drivers to communicate with external chips
by doing I/O with the not-used-for-MIDI UART.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'sound/pci/oxygen/oxygen_lib.c')
| -rw-r--r-- | sound/pci/oxygen/oxygen_lib.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/sound/pci/oxygen/oxygen_lib.c b/sound/pci/oxygen/oxygen_lib.c index b1997216b4af..84f481d41efa 100644 --- a/sound/pci/oxygen/oxygen_lib.c +++ b/sound/pci/oxygen/oxygen_lib.c @@ -35,6 +35,30 @@ MODULE_DESCRIPTION("C-Media CMI8788 helper library"); MODULE_LICENSE("GPL v2"); +static inline int oxygen_uart_input_ready(struct oxygen *chip) +{ + return !(oxygen_read8(chip, OXYGEN_MPU401 + 1) & MPU401_RX_EMPTY); +} + +static void oxygen_read_uart(struct oxygen *chip) +{ + if (unlikely(!oxygen_uart_input_ready(chip))) { + /* no data, but read it anyway to clear the interrupt */ + oxygen_read8(chip, OXYGEN_MPU401); + return; + } + do { + u8 data = oxygen_read8(chip, OXYGEN_MPU401); + if (data == MPU401_ACK) + continue; + if (chip->uart_input_count >= ARRAY_SIZE(chip->uart_input)) + chip->uart_input_count = 0; + chip->uart_input[chip->uart_input_count++] = data; + } while (oxygen_uart_input_ready(chip)); + if (chip->model.uart_input) + chip->model.uart_input(chip); +} + static irqreturn_t oxygen_interrupt(int dummy, void *dev_id) { struct oxygen *chip = dev_id; @@ -87,8 +111,12 @@ static irqreturn_t oxygen_interrupt(int dummy, void *dev_id) if (status & OXYGEN_INT_GPIO) schedule_work(&chip->gpio_work); - if ((status & OXYGEN_INT_MIDI) && chip->midi) - snd_mpu401_uart_interrupt(0, chip->midi->private_data); + if (status & OXYGEN_INT_MIDI) { + if (chip->midi) + snd_mpu401_uart_interrupt(0, chip->midi->private_data); + else + oxygen_read_uart(chip); + } if (status & OXYGEN_INT_AC97) wake_up(&chip->ac97_waitqueue); |