devs/foxbox
1
0
Fork 0
forked from len0rd/rockbox
Code Pull requests Activity

Finer grained irq masking, blocking for i2c, plus a mutex to prevent conflicting read/writes

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8922 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Brandon Low 2006-03-05 22:14:53 +00:00
parent 03b8708f9e
commit bb2f15ca7d
4 changed files with 57 additions and 67 deletions
Download patch file Download diff file Expand all files Collapse all files

88
firmware/drivers/i2c-pp5020.c
View file

@ -57,42 +57,48 @@ static int ipod_i2c_wait_not_busy(void)
if (!(inb(IPOD_I2C_STATUS) & IPOD_I2C_BUSY)) {
return 0;
}
yield();
}
return -1;
}
/* Public functions */
int ipod_i2c_read_byte(unsigned int addr, unsigned int *data)
static int ipod_i2c_read_byte(unsigned int addr, unsigned int *data)
{
if (ipod_i2c_wait_not_busy() < 0)
{
return -1;
}
/* clear top 15 bits, left shift 1, or in 0x1 for a read */
outb(((addr << 17) >> 16) | 0x1, IPOD_I2C_ADDR);
outb(inb(IPOD_I2C_CTRL) | 0x20, IPOD_I2C_CTRL);
outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
if (ipod_i2c_wait_not_busy() < 0)
{
return -1;
}
int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
if (data)
{
*data = inb(IPOD_I2C_DATA0);
/* clear top 15 bits, left shift 1, or in 0x1 for a read */
outb(((addr << 17) >> 16) | 0x1, IPOD_I2C_ADDR);
outb(inb(IPOD_I2C_CTRL) | 0x20, IPOD_I2C_CTRL);
outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
set_irq_level(old_irq_level);
if (data)
{
if (ipod_i2c_wait_not_busy() < 0)
{
return -1;
}
old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
*data = inb(IPOD_I2C_DATA0);
set_irq_level(old_irq_level);
}
}
return 0;
}
int ipod_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char *data)
static int ipod_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char *data)
{
int data_addr;
unsigned int i;
@ -107,26 +113,32 @@ int ipod_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char *data
return -2;
}
/* clear top 15 bits, left shift 1 */
outb((addr << 17) >> 16, IPOD_I2C_ADDR);
outb(inb(IPOD_I2C_CTRL) & ~0x20, IPOD_I2C_CTRL);
data_addr = IPOD_I2C_DATA0;
for ( i = 0; i < len; i++ )
{
outb(*data++, data_addr);
data_addr += 4;
int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
/* clear top 15 bits, left shift 1 */
outb((addr << 17) >> 16, IPOD_I2C_ADDR);
outb(inb(IPOD_I2C_CTRL) & ~0x20, IPOD_I2C_CTRL);
data_addr = IPOD_I2C_DATA0;
for ( i = 0; i < len; i++ )
{
outb(*data++, data_addr);
data_addr += 4;
}
outb((inb(IPOD_I2C_CTRL) & ~0x26) | ((len-1) << 1), IPOD_I2C_CTRL);
outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
set_irq_level(old_irq_level);
}
outb((inb(IPOD_I2C_CTRL) & ~0x26) | ((len-1) << 1), IPOD_I2C_CTRL);
outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
return 0x0;
}
int ipod_i2c_send_byte(unsigned int addr, int data0)
static int ipod_i2c_send_byte(unsigned int addr, int data0)
{
unsigned char data[1];
@ -135,25 +147,35 @@ int ipod_i2c_send_byte(unsigned int addr, int data0)
return ipod_i2c_send_bytes(addr, 1, data);
}
/* Public functions */
static struct mutex i2c_mutex;
int i2c_readbyte(unsigned int dev_addr, int addr)
{
int retval;
int data;
mutex_lock(&i2c_mutex);
ipod_i2c_send_byte(dev_addr, addr);
ipod_i2c_read_byte(dev_addr, &data);
mutex_unlock(&i2c_mutex);
return data;
}
int ipod_i2c_send(unsigned int addr, int data0, int data1)
{
int retval;
unsigned char data[2];
data[0] = data0;
data[1] = data1;
return ipod_i2c_send_bytes(addr, 2, data);
mutex_lock(&i2c_mutex);
retval = ipod_i2c_send_bytes(addr, 2, data);
mutex_unlock(&i2c_mutex);
return retval;
}
void i2c_init(void)
@ -175,5 +197,7 @@ void i2c_init(void)
outl(0x0, 0x600060a4);
outl(0x80 | (0 << 8), 0x600060a4);
mutex_init(&i2c_mutex);
i2c_readbyte(0x8, 0);
}