diff options
| -rw-r--r-- | drivers/i2c/mvtwsi.c | 127 |
1 files changed, 85 insertions, 42 deletions
diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c index 8552fba7b6..f060cd1114 100644 --- a/drivers/i2c/mvtwsi.c +++ b/drivers/i2c/mvtwsi.c @@ -12,6 +12,7 @@ #include <i2c.h> #include <asm/errno.h> #include <asm/io.h> +#include <linux/compat.h> #ifdef CONFIG_DM_I2C #include <dm.h> #endif @@ -78,6 +79,8 @@ struct mvtwsi_i2c_dev { u8 slaveadd; /* The configured I2C speed in Hz */ uint speed; + /* The current length of a clock period (depending on speed) */ + uint tick; }; #endif /* CONFIG_DM_I2C */ @@ -154,7 +157,15 @@ enum mvtwsi_ack_flags { MVTWSI_READ_ACK = 1, }; +inline uint calc_tick(uint speed) +{ + /* One tick = the duration of a period at the specified speed in ns (we + * add 100 ns to be on the safe side) */ + return (1000000000u / speed) + 100; +} + #ifndef CONFIG_DM_I2C + /* * MVTWSI controller base */ @@ -230,7 +241,8 @@ inline uint mvtwsi_error(uint ec, uint lc, uint ls, uint es) * Wait for IFLG to raise, or return 'timeout.' Then, if the status is as * expected, return 0 (ok) or 'wrong status' otherwise. */ -static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status) +static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status, + uint tick) { int control, status; int timeout = 1000; @@ -246,7 +258,7 @@ static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status) MVTWSI_ERROR_WRONG_STATUS, control, status, expected_status); } - udelay(10); /* One clock cycle at 100 kHz */ + ndelay(tick); /* One clock cycle */ } while (timeout--); status = readl(&twsi->status); return mvtwsi_error(MVTWSI_ERROR_TIMEOUT, control, status, @@ -257,20 +269,21 @@ static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status) * Assert the START condition, either in a single I2C transaction * or inside back-to-back ones (repeated starts). */ -static int twsi_start(struct mvtwsi_registers *twsi, int expected_status) +static int twsi_start(struct mvtwsi_registers *twsi, int expected_status, + uint tick) { /* Assert START */ writel(MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_START | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control); /* Wait for controller to process START */ - return twsi_wait(twsi, expected_status); + return twsi_wait(twsi, expected_status, tick); } /* * Send a byte (i2c address or data). */ static int twsi_send(struct mvtwsi_registers *twsi, u8 byte, - int expected_status) + int expected_status, uint tick) { /* Write byte to data register for sending */ writel(byte, &twsi->data); @@ -278,13 +291,14 @@ static int twsi_send(struct mvtwsi_registers *twsi, u8 byte, writel(MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control); /* Wait for controller to receive byte, and check ACK */ - return twsi_wait(twsi, expected_status); + return twsi_wait(twsi, expected_status, tick); } /* * Receive a byte. */ -static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag) +static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag, + uint tick) { int expected_status, status, control; @@ -296,7 +310,7 @@ static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag) control |= ack_flag == MVTWSI_READ_ACK ? MVTWSI_CONTROL_ACK : 0; writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control); /* Wait for controller to receive byte, and assert ACK or NAK */ - status = twsi_wait(twsi, expected_status); + status = twsi_wait(twsi, expected_status, tick); /* If we did receive the expected byte, store it */ if (status == 0) *byte = readl(&twsi->data); @@ -307,7 +321,7 @@ static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag) * Assert the STOP condition. * This is also used to force the bus back to idle (SDA = SCL = 1). */ -static int twsi_stop(struct mvtwsi_registers *twsi) +static int twsi_stop(struct mvtwsi_registers *twsi, uint tick) { int control, stop_status; int status = 0; @@ -321,7 +335,7 @@ static int twsi_stop(struct mvtwsi_registers *twsi) stop_status = readl(&twsi->status); if (stop_status == MVTWSI_STATUS_IDLE) break; - udelay(10); /* One clock cycle at 100 kHz */ + ndelay(tick); /* One clock cycle */ } while (timeout--); control = readl(&twsi->control); if (stop_status != MVTWSI_STATUS_IDLE) @@ -376,21 +390,32 @@ static uint __twsi_i2c_set_bus_speed(struct mvtwsi_registers *twsi, } } writel(baud, &twsi->baudrate); - return 0; + + /* Wait for controller for one tick */ +#ifdef CONFIG_DM_I2C + ndelay(calc_tick(highest_speed)); +#else + ndelay(10000); +#endif + return highest_speed; } static void __twsi_i2c_init(struct mvtwsi_registers *twsi, int speed, - int slaveadd) + int slaveadd, uint *actual_speed) { /* Reset controller */ twsi_reset(twsi); /* Set speed */ - __twsi_i2c_set_bus_speed(twsi, speed); + *actual_speed = __twsi_i2c_set_bus_speed(twsi, speed); /* Set slave address; even though we don't use it */ writel(slaveadd, &twsi->slave_address); writel(0, &twsi->xtnd_slave_addr); /* Assert STOP, but don't care for the result */ - (void) twsi_stop(twsi); +#ifdef CONFIG_DM_I2C + (void) twsi_stop(twsi, calc_tick(*actual_speed)); +#else + (void) twsi_stop(twsi, 10000); +#endif } /* @@ -398,7 +423,7 @@ static void __twsi_i2c_init(struct mvtwsi_registers *twsi, int speed, * Expected address status will derive from direction bit (bit 0) in addr. */ static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status, - u8 addr) + u8 addr, uint tick) { int status, expected_addr_status; @@ -409,10 +434,10 @@ static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status, else /* Writing */ expected_addr_status = MVTWSI_STATUS_ADDR_W_ACK; /* Assert START */ - status = twsi_start(twsi, expected_start_status); + status = twsi_start(twsi, expected_start_status, tick); /* Send out the address if the start went well */ if (status == 0) - status = twsi_send(twsi, addr, expected_addr_status); + status = twsi_send(twsi, addr, expected_addr_status, tick); /* Return 0, or the status of the first failure */ return status; } @@ -420,18 +445,19 @@ static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status, /* * Begin read, nak data byte, end. */ -static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip) +static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip, + uint tick) { u8 dummy_byte; int status; /* Begin i2c read */ - status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1) | 1); + status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1) | 1, tick); /* Dummy read was accepted: receive byte, but NAK it. */ if (status == 0) - status = twsi_recv(twsi, &dummy_byte, MVTWSI_READ_NAK); + status = twsi_recv(twsi, &dummy_byte, MVTWSI_READ_NAK, tick); /* Stop transaction */ - twsi_stop(twsi); + twsi_stop(twsi, tick); /* Return 0, or the status of the first failure */ return status; } @@ -445,7 +471,8 @@ static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip) * will be a repeated start without a preceding stop. */ static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip, - u8 *addr, int alen, uchar *data, int length) + u8 *addr, int alen, uchar *data, int length, + uint tick) { int status = 0; int stop_status; @@ -453,25 +480,25 @@ static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip, if (alen > 0) { /* Begin i2c write to send the address bytes */ - status = i2c_begin(twsi, expected_start, (chip << 1)); + status = i2c_begin(twsi, expected_start, (chip << 1), tick); /* Send address bytes */ while ((status == 0) && alen--) status = twsi_send(twsi, *(addr++), - MVTWSI_STATUS_DATA_W_ACK); + MVTWSI_STATUS_DATA_W_ACK, tick); /* Send repeated STARTs after the initial START */ expected_start = MVTWSI_STATUS_REPEATED_START; } /* Begin i2c read to receive data bytes */ if (status == 0) - status = i2c_begin(twsi, expected_start, (chip << 1) | 1); + status = i2c_begin(twsi, expected_start, (chip << 1) | 1, tick); /* Receive actual data bytes; set NAK if we if we have nothing more to * read */ while ((status == 0) && length--) status = twsi_recv(twsi, data++, length > 0 ? - MVTWSI_READ_ACK : MVTWSI_READ_NAK); + MVTWSI_READ_ACK : MVTWSI_READ_NAK, tick); /* Stop transaction */ - stop_status = twsi_stop(twsi); + stop_status = twsi_stop(twsi, tick); /* Return 0, or the status of the first failure */ return status != 0 ? status : stop_status; } @@ -480,21 +507,24 @@ static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip, * Begin write, send address byte(s), send data bytes, end. */ static int __twsi_i2c_write(struct mvtwsi_registers *twsi, uchar chip, - u8 *addr, int alen, uchar *data, int length) + u8 *addr, int alen, uchar *data, int length, + uint tick) { int status, stop_status; /* Begin i2c write to send first the address bytes, then the * data bytes */ - status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1)); + status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1), tick); /* Send address bytes */ while ((status == 0) && (alen-- > 0)) - status = twsi_send(twsi, *(addr++), MVTWSI_STATUS_DATA_W_ACK); + status = twsi_send(twsi, *(addr++), MVTWSI_STATUS_DATA_W_ACK, + tick); /* Send data bytes */ while ((status == 0) && (length-- > 0)) - status = twsi_send(twsi, *(data++), MVTWSI_STATUS_DATA_W_ACK); + status = twsi_send(twsi, *(data++), MVTWSI_STATUS_DATA_W_ACK, + tick); /* Stop transaction */ - stop_status = twsi_stop(twsi); + stop_status = twsi_stop(twsi, tick); /* Return 0, or the status of the first failure */ return status != 0 ? status : stop_status; } @@ -504,20 +534,21 @@ static void twsi_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd) { struct mvtwsi_registers *twsi = twsi_get_base(adap); - __twsi_i2c_init(twsi, speed, slaveadd); + __twsi_i2c_init(twsi, speed, slaveadd, NULL); } static uint twsi_i2c_set_bus_speed(struct i2c_adapter *adap, uint requested_speed) { struct mvtwsi_registers *twsi = twsi_get_base(adap); - return __twsi_i2c_set_bus_speed(twsi, requested_speed); + __twsi_i2c_set_bus_speed(twsi, requested_speed); + return 0; } static int twsi_i2c_probe(struct i2c_adapter *adap, uchar chip) { struct mvtwsi_registers *twsi = twsi_get_base(adap); - return __twsi_i2c_probe_chip(twsi, chip); + return __twsi_i2c_probe_chip(twsi, chip, 10000); } static int twsi_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr, @@ -531,7 +562,8 @@ static int twsi_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr, addr_bytes[2] = (addr >> 16) & 0xFF; addr_bytes[3] = (addr >> 24) & 0xFF; - return __twsi_i2c_read(twsi, chip, addr_bytes, alen, data, length); + return __twsi_i2c_read(twsi, chip, addr_bytes, alen, data, length, + 10000); } static int twsi_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr, @@ -545,7 +577,8 @@ static int twsi_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr, addr_bytes[2] = (addr >> 16) & 0xFF; addr_bytes[3] = (addr >> 24) & 0xFF; - return __twsi_i2c_write(twsi, chip, addr_bytes, alen, data, length); + return __twsi_i2c_write(twsi, chip, addr_bytes, alen, data, length, + 10000); } #ifdef CONFIG_I2C_MVTWSI_BASE0 @@ -595,13 +628,17 @@ static int mvtwsi_i2c_probe_chip(struct udevice *bus, u32 chip_addr, u32 chip_flags) { struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); - return __twsi_i2c_probe_chip(dev->base, chip_addr); + return __twsi_i2c_probe_chip(dev->base, chip_addr, dev->tick); } static int mvtwsi_i2c_set_bus_speed(struct udevice *bus, uint speed) { struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); - return __twsi_i2c_set_bus_speed(dev->base, speed); + + dev->speed = __twsi_i2c_set_bus_speed(dev->base, speed); + dev->tick = calc_tick(dev->speed); + + return 0; } static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus) @@ -625,7 +662,11 @@ static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus) static int mvtwsi_i2c_probe(struct udevice *bus) { struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); - __twsi_i2c_init(dev->base, dev->speed, dev->slaveadd); + uint actual_speed; + + __twsi_i2c_init(dev->base, dev->speed, dev->slaveadd, &actual_speed); + dev->speed = actual_speed; + dev->tick = calc_tick(dev->speed); return 0; } @@ -648,10 +689,12 @@ static int mvtwsi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) if (dmsg->flags & I2C_M_RD) return __twsi_i2c_read(dev->base, dmsg->addr, omsg->buf, - omsg->len, dmsg->buf, dmsg->len); + omsg->len, dmsg->buf, dmsg->len, + dev->tick); else return __twsi_i2c_write(dev->base, dmsg->addr, omsg->buf, - omsg->len, dmsg->buf, dmsg->len); + omsg->len, dmsg->buf, dmsg->len, + dev->tick); } static const struct dm_i2c_ops mvtwsi_i2c_ops = { |