X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=drivers%2Fi2c%2Fmvtwsi.c;h=648a96eeb4e88cd0ab9b753b31c8d85b9b33d4e5;hb=af8ef2ed21960b894945e37a3217ad67373f3711;hp=f694527ec6ffe729a365ebac0a4a2d2d8f6b1ffe;hpb=14a6ff2c4f22010e5d67f25508f09e3b53a1f1c4;p=oweals%2Fu-boot.git diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c index f694527ec6..648a96eeb4 100644 --- a/drivers/i2c/mvtwsi.c +++ b/drivers/i2c/mvtwsi.c @@ -10,8 +10,9 @@ #include #include -#include +#include #include +#include #ifdef CONFIG_DM_I2C #include #endif @@ -28,7 +29,7 @@ DECLARE_GLOBAL_DATA_PTR; #include #elif (defined(CONFIG_KIRKWOOD) || defined(CONFIG_ARCH_MVEBU)) #include -#elif defined(CONFIG_SUNXI) +#elif defined(CONFIG_ARCH_SUNXI) #include #else #error Driver mvtwsi not supported by SoC or board @@ -39,7 +40,7 @@ DECLARE_GLOBAL_DATA_PTR; * TWSI register structure */ -#ifdef CONFIG_SUNXI +#ifdef CONFIG_ARCH_SUNXI struct mvtwsi_registers { u32 slave_address; @@ -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 */ @@ -154,11 +157,27 @@ enum mvtwsi_ack_flags { MVTWSI_READ_ACK = 1, }; -#ifndef CONFIG_DM_I2C /* - * MVTWSI controller base + * calc_tick() - Calculate the duration of a clock cycle from the I2C speed + * + * @speed: The speed in Hz to calculate the clock cycle duration for. + * @return The duration of a clock cycle in ns. */ +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 + +/* + * twsi_get_base() - Get controller register base for specified adapter + * + * @adap: Adapter to get the register base for. + * @return Register base for the specified adapter. + */ static struct mvtwsi_registers *twsi_get_base(struct i2c_adapter *adap) { switch (adap->hwadapnr) { @@ -227,10 +246,13 @@ 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. + * twsi_wait() - Wait for I2C bus interrupt flag and check status, or time out. + * + * @return Zero if status is as expected, or a non-zero code if either a time + * out occurred, or the status was not the expected one. */ -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 +268,7 @@ 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, @@ -254,23 +276,43 @@ 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). + * twsi_start() - Assert a START condition on the bus. + * + * This function is used in both single I2C transactions and inside + * back-to-back transactions (repeated starts). + * + * @twsi: The MVTWSI register structure to use. + * @expected_status: The I2C bus status expected to be asserted after the + * operation completion. + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if status is as expected, or a non-zero code if either a time + * out occurred or the status was not the expected one. */ -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). + * twsi_send() - Send a byte on the I2C bus. + * + * The byte may be part of an address byte or data. + * + * @twsi: The MVTWSI register structure to use. + * @byte: The byte to send. + * @expected_status: The I2C bus status expected to be asserted after the + * operation completion. + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if status is as expected, or a non-zero code if either a time + * out occurred or the status was not the expected one. */ 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 +320,24 @@ 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. + * twsi_recv() - Receive a byte on the I2C bus. + * + * The static variable mvtwsi_control_flags controls whether we ack or nak. + * + * @twsi: The MVTWSI register structure to use. + * @byte: The byte to send. + * @ack_flag: Flag that determines whether the received byte should + * be acknowledged by the controller or not (sent ACK/NAK). + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if status is as expected, or a non-zero code if either a time + * out occurred or the status was not the expected one. */ -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 +349,7 @@ 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); @@ -304,10 +357,17 @@ 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). + * twsi_stop() - Assert a STOP condition on the bus. + * + * This function is also used to force the bus back to idle state (SDA = + * SCL = 1). + * + * @twsi: The MVTWSI register structure to use. + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if the operation succeeded, or a non-zero code if a time out + * occurred. */ -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 +381,7 @@ 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) @@ -330,9 +390,16 @@ static int twsi_stop(struct mvtwsi_registers *twsi) return status; } +/* + * twsi_calc_freq() - Compute I2C frequency depending on m and n parameters. + * + * @n: Parameter 'n' for the frequency calculation algorithm. + * @m: Parameter 'm' for the frequency calculation algorithm. + * @return The I2C frequency corresponding to the passed m and n parameters. + */ static uint twsi_calc_freq(const int n, const int m) { -#ifdef CONFIG_SUNXI +#ifdef CONFIG_ARCH_SUNXI return CONFIG_SYS_TCLK / (10 * (m + 1) * (1 << n)); #else return CONFIG_SYS_TCLK / (10 * (m + 1) * (2 << n)); @@ -340,9 +407,12 @@ static uint twsi_calc_freq(const int n, const int m) } /* - * Reset controller. - * Controller reset also resets the baud rate and slave address, so - * they must be re-established afterwards. + * twsi_reset() - Reset the I2C controller. + * + * Resetting the controller also resets the baud rate and slave address, hence + * they must be re-established after the reset. + * + * @twsi: The MVTWSI register structure to use. */ static void twsi_reset(struct mvtwsi_registers *twsi) { @@ -353,7 +423,15 @@ static void twsi_reset(struct mvtwsi_registers *twsi) } /* - * Sets baud to the highest possible value not exceeding the requested one. + * __twsi_i2c_set_bus_speed() - Set the speed of the I2C controller. + * + * This function sets baud rate to the highest possible value that does not + * exceed the requested rate. + * + * @twsi: The MVTWSI register structure to use. + * @requested_speed: The desired frequency the controller should run at + * in Hz. + * @return The actual frequency the controller was configured to. */ static uint __twsi_i2c_set_bus_speed(struct mvtwsi_registers *twsi, uint requested_speed) @@ -376,29 +454,65 @@ 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; } +/* + * __twsi_i2c_init() - Initialize the I2C controller. + * + * @twsi: The MVTWSI register structure to use. + * @speed: The initial frequency the controller should run at + * in Hz. + * @slaveadd: The I2C address to be set for the I2C master. + * @actual_speed: A output parameter that receives the actual frequency + * in Hz the controller was set to by the function. + * @return Zero if the operation succeeded, or a non-zero code if a time out + * occurred. + */ 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 } /* - * Begin I2C transaction with expected start status, at given address. - * Expected address status will derive from direction bit (bit 0) in addr. + * i2c_begin() - Start a I2C transaction. + * + * Begin a I2C transaction with a given expected start status and chip address. + * A START is asserted, and the address byte is sent to the I2C controller. The + * expected address status will be derived from the direction bit (bit 0) of + * the address byte. + * + * @twsi: The MVTWSI register structure to use. + * @expected_start_status: The I2C status the controller is expected to + * assert after the address byte was sent. + * @addr: The address byte to be sent. + * @tick: The duration of a clock cycle at the current + * I2C speed. + * @return Zero if the operation succeeded, or a non-zero code if a time out or + * unexpected I2C status occurred. */ static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status, - u8 addr) + u8 addr, uint tick) { int status, expected_addr_status; @@ -409,87 +523,133 @@ 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; } /* - * Begin read, nak data byte, end. + * __twsi_i2c_probe_chip() - Probe the given I2C chip address. + * + * This function begins a I2C read transaction, does a dummy read and NAKs; if + * the procedure succeeds, the chip is considered to be present. + * + * @twsi: The MVTWSI register structure to use. + * @chip: The chip address to probe. + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if the operation succeeded, or a non-zero code if a time out or + * unexpected I2C status occurred. */ -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; } /* - * Begin write, send address byte(s), begin read, receive data bytes, end. + * __twsi_i2c_read() - Read data from a I2C chip. + * + * This function begins a I2C write transaction, and transmits the address + * bytes; then begins a I2C read transaction, and receives the data bytes. * * NOTE: Some devices want a stop right before the second start, while some * will choke if it is there. Since deciding this is not yet supported in * higher level APIs, we need to make a decision here, and for the moment that * will be a repeated start without a preceding stop. + * + * @twsi: The MVTWSI register structure to use. + * @chip: The chip address to read from. + * @addr: The address bytes to send. + * @alen: The length of the address bytes in bytes. + * @data: The buffer to receive the data read from the chip (has to have + * a size of at least 'length' bytes). + * @length: The amount of data to be read from the chip in bytes. + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if the operation succeeded, or a non-zero code if a time out or + * unexpected I2C status occurred. */ 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; - - /* Begin i2c write to send the address bytes */ - status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1)); - /* Send address bytes */ - while ((status == 0) && alen--) - status = twsi_send(twsi, *(addr++), MVTWSI_STATUS_DATA_W_ACK); + int expected_start = MVTWSI_STATUS_START; + + if (alen > 0) { + /* Begin i2c write to send the address bytes */ + status = i2c_begin(twsi, expected_start, (chip << 1), tick); + /* Send address bytes */ + while ((status == 0) && alen--) + status = twsi_send(twsi, addr[alen], + 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, MVTWSI_STATUS_REPEATED_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; } /* - * Begin write, send address byte(s), send data bytes, end. + * __twsi_i2c_write() - Send data to a I2C chip. + * + * This function begins a I2C write transaction, and transmits the address + * bytes; then begins a new I2C write transaction, and sends the data bytes. + * + * @twsi: The MVTWSI register structure to use. + * @chip: The chip address to read from. + * @addr: The address bytes to send. + * @alen: The length of the address bytes in bytes. + * @data: The buffer containing the data to be sent to the chip. + * @length: The length of data to be sent to the chip in bytes. + * @tick: The duration of a clock cycle at the current I2C speed. + * @return Zero if the operation succeeded, or a non-zero code if a time out or + * unexpected I2C status occurred. */ 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[alen], 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; } @@ -499,20 +659,21 @@ 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, @@ -526,7 +687,8 @@ 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, @@ -540,7 +702,8 @@ 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 @@ -590,13 +753,17 @@ 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) @@ -608,11 +775,11 @@ static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus) if (!dev->base) return -ENOMEM; - dev->index = fdtdec_get_int(gd->fdt_blob, bus->of_offset, + dev->index = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus), "cell-index", -1); - dev->slaveadd = fdtdec_get_int(gd->fdt_blob, bus->of_offset, + dev->slaveadd = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus), "u-boot,i2c-slave-addr", 0x0); - dev->speed = fdtdec_get_int(gd->fdt_blob, bus->of_offset, + dev->speed = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus), "clock-frequency", 100000); return 0; } @@ -620,7 +787,11 @@ 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; } @@ -643,10 +814,12 @@ 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 = { @@ -657,6 +830,7 @@ static const struct dm_i2c_ops mvtwsi_i2c_ops = { static const struct udevice_id mvtwsi_i2c_ids[] = { { .compatible = "marvell,mv64xxx-i2c", }, + { .compatible = "marvell,mv78230-i2c", }, { /* sentinel */ } };