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Switch S5L8702 I2C to ECLK, add I2C support for S5L8720

Tested on ipod6g (normal and bootloader builds)

This is a part of the large iPod Nano 3G and iPod Nano 4G support patch.

Credit: Cástor Muñoz <cmvidal@gmail.com>
Change-Id: I7c21ce2ecb6f94c0b8af4b7b16b3b77c39c6a0a4
This commit is contained in:
Vencislav Atanasov 2024-12-09 19:38:46 +02:00
parent ca5f12ae58
commit 68c51456ff

View file

@ -55,6 +55,11 @@ static void i2c_on(int bus)
{
/* enable I2C clock */
clockgate_enable(I2CCLKGATE(bus), true);
#if CONFIG_CPU == S5L8720
/* this clockgate is needed when ECLK is used as source clock */
clockgate_enable(I2CCLKGATE_2(bus), true);
udelay(5);
#endif
}
static void i2c_off(int bus)
@ -65,6 +70,9 @@ static void i2c_off(int bus)
/* disable I2C clock */
wait_rdy(bus);
clockgate_enable(I2CCLKGATE(bus), false);
#if CONFIG_CPU == S5L8720
clockgate_enable(I2CCLKGATE_2(bus), false);
#endif
}
/* wait for bus not busy, or tx/rx byte (should return once
@ -84,15 +92,29 @@ static int i2c_start(int bus, unsigned char slave, bool rd)
wait_rdy(bus);
IICCON(bus) = (0 << 8) | /* INT_EN = disabled */
(1 << 7) | /* ACK_GEN */
(0 << 6) | /* CLKSEL = PCLK/32 (TBC) */
(4 << 0); /* CK_REG */
(0 << 6) | /* CLKSEL = SRCCLK/32 (TBC) */
#if CONFIG_CPU == S5L8702
(0 << 0); /* CK_REG */
#elif CONFIG_CPU == S5L8720
(1 << 0); /* CK_REG */
#endif
/* START */
int mode = rd ? 0x80 : 0xC0;
wait_rdy(bus);
IICSTAT(bus) = mode;
wait_rdy(bus);
IICDS(bus) = slave | rd;
wait_rdy(bus);
IICSTAT(bus) = rd ? 0xB0 : 0xF0;
IICSTAT(bus) = mode | 0x30;
#if CONFIG_CPU == S5L8702
// XXX this seems needed when ECLK is used
wait_rdy(bus); // XXX: To solve the nano3g problem with ECLK,
// or you can put it in either of the two i2c_wait_io(),
// both work if you put this
// TODO: Try on classic, maybe it's not necessary
#endif
i2c_wait_io(bus);
/* check ACK */
@ -207,13 +229,24 @@ int i2c_read(int bus, unsigned char slave, int address, int len, unsigned char *
void i2c_preinit(int bus)
{
if (bus == 0) PCON3 = (PCON3 & ~0x00000ff0) | 0x00000220;
/* TBC: else if(bus == 1) PCON6 = (PCON6 & ~0x0ff00000) | 0x02200000; */
#if CONFIG_CPU == S5L8702
if (bus == 0)
PCON3 = (PCON3 & ~0x00000ff0) | 0x00000220;
#if 0 /* TBC */
else if (bus == 1)
PCON6 = (PCON6 & ~0x0ff00000) | 0x02200000;
#endif
#elif CONFIG_CPU == S5L8720
if (bus == 0) {
PCON2 = (PCON2 & ~0xf0000000) | 0x20000000;
PCON3 = (PCON3 & ~0x0000000f) | 0x00000002;
}
#endif
i2c_on(bus);
wait_rdy(bus);
IICADD(bus) = 0x40; /* own slave address */
wait_rdy(bus);
IICUNK14(bus) = 0;
IICUNK14(bus) = 1; /* SRCCLK = ECLK */
wait_rdy(bus);
IICUNK18(bus) = 0;
wait_rdy(bus);