Commit 397b1dcc authored by Clemens Ladisch's avatar Clemens Ladisch
Browse files

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: default avatarClemens Ladisch <clemens@ladisch.de>
parent dbbbd674

sound/pci/oxygen/oxygen.h

+6 −0
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ struct oxygen_model { 
	void (*update_dac_volume)(struct oxygen *chip);

	void (*update_dac_mute)(struct oxygen *chip);

	void (*gpio_changed)(struct oxygen *chip);

	void (*uart_input)(struct oxygen *chip);

	void (*ac97_switch)(struct oxygen *chip,

			    unsigned int reg, unsigned int mute);

	const unsigned int *dac_tlv;
@@ -125,6 +126,8 @@ struct oxygen { 
		__le32 _32[OXYGEN_IO_SIZE / 4];

	} saved_registers;

	u16 saved_ac97_registers[2][0x40];

	unsigned int uart_input_count;

	u8 uart_input[32];

	struct oxygen_model model;

};
@@ -174,6 +177,9 @@ void oxygen_write_ac97_masked(struct oxygen *chip, unsigned int codec, 
void oxygen_write_spi(struct oxygen *chip, u8 control, unsigned int data);

void oxygen_write_i2c(struct oxygen *chip, u8 device, u8 map, u8 data);



void oxygen_reset_uart(struct oxygen *chip);

void oxygen_write_uart(struct oxygen *chip, u8 data);



static inline void oxygen_set_bits8(struct oxygen *chip,

				    unsigned int reg, u8 value)

{

sound/pci/oxygen/oxygen_io.c

+21 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/delay.h>

#include <linux/sched.h>

#include <sound/core.h>

#include <sound/mpu401.h>

#include <asm/io.h>

#include "oxygen.h"
@@ -232,3 +233,23 @@ void oxygen_write_i2c(struct oxygen *chip, u8 device, u8 map, u8 data) 
		      device | OXYGEN_2WIRE_DIR_WRITE);

}

EXPORT_SYMBOL(oxygen_write_i2c);



static void _write_uart(struct oxygen *chip, unsigned int port, u8 data)

{

	if (oxygen_read8(chip, OXYGEN_MPU401 + 1) & MPU401_TX_FULL)

		msleep(1);

	oxygen_write8(chip, OXYGEN_MPU401 + port, data);

}



void oxygen_reset_uart(struct oxygen *chip)

{

	_write_uart(chip, 1, MPU401_RESET);

	_write_uart(chip, 1, MPU401_ENTER_UART);

}

EXPORT_SYMBOL(oxygen_reset_uart);



void oxygen_write_uart(struct oxygen *chip, u8 data)

{

	_write_uart(chip, 0, data);

}

EXPORT_SYMBOL(oxygen_write_uart);

sound/pci/oxygen/oxygen_lib.c

+30 −2
Original line number Diff line number Diff line
@@ -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)

	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);