| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Driver for the TWSI (i2c) controller found on the Marvell |
| * orion5x and kirkwood SoC families. |
| * |
| * Author: Albert Aribaud <albert.u.boot@aribaud.net> |
| * Copyright (c) 2010 Albert Aribaud. |
| */ |
| |
| #include <common.h> |
| #include <i2c.h> |
| #include <linux/errno.h> |
| #include <asm/io.h> |
| #include <linux/bitops.h> |
| #include <linux/compat.h> |
| #ifdef CONFIG_DM_I2C |
| #include <dm.h> |
| #endif |
| |
| DECLARE_GLOBAL_DATA_PTR; |
| |
| /* |
| * Include a file that will provide CONFIG_I2C_MVTWSI_BASE*, and possibly other |
| * settings |
| */ |
| |
| #ifndef CONFIG_DM_I2C |
| #if defined(CONFIG_ORION5X) |
| #include <asm/arch/orion5x.h> |
| #elif (defined(CONFIG_KIRKWOOD) || defined(CONFIG_ARCH_MVEBU)) |
| #include <asm/arch/soc.h> |
| #elif defined(CONFIG_ARCH_SUNXI) |
| #include <asm/arch/i2c.h> |
| #else |
| #error Driver mvtwsi not supported by SoC or board |
| #endif |
| #endif /* CONFIG_DM_I2C */ |
| |
| /* |
| * On SUNXI, we get CONFIG_SYS_TCLK from this include, so we want to |
| * always have it. |
| */ |
| #if defined(CONFIG_DM_I2C) && defined(CONFIG_ARCH_SUNXI) |
| #include <asm/arch/i2c.h> |
| #endif |
| |
| /* |
| * TWSI register structure |
| */ |
| |
| #ifdef CONFIG_ARCH_SUNXI |
| |
| struct mvtwsi_registers { |
| u32 slave_address; |
| u32 xtnd_slave_addr; |
| u32 data; |
| u32 control; |
| u32 status; |
| u32 baudrate; |
| u32 soft_reset; |
| u32 debug; /* Dummy field for build compatibility with mvebu */ |
| }; |
| |
| #else |
| |
| struct mvtwsi_registers { |
| u32 slave_address; |
| u32 data; |
| u32 control; |
| union { |
| u32 status; /* When reading */ |
| u32 baudrate; /* When writing */ |
| }; |
| u32 xtnd_slave_addr; |
| u32 reserved0[2]; |
| u32 soft_reset; |
| u32 reserved1[27]; |
| u32 debug; |
| }; |
| |
| #endif |
| |
| #ifdef CONFIG_DM_I2C |
| struct mvtwsi_i2c_dev { |
| /* TWSI Register base for the device */ |
| struct mvtwsi_registers *base; |
| /* Number of the device (determined from cell-index property) */ |
| int index; |
| /* The I2C slave address for the device */ |
| 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 */ |
| |
| /* |
| * enum mvtwsi_ctrl_register_fields - Bit masks for flags in the control |
| * register |
| */ |
| enum mvtwsi_ctrl_register_fields { |
| /* Acknowledge bit */ |
| MVTWSI_CONTROL_ACK = 0x00000004, |
| /* Interrupt flag */ |
| MVTWSI_CONTROL_IFLG = 0x00000008, |
| /* Stop bit */ |
| MVTWSI_CONTROL_STOP = 0x00000010, |
| /* Start bit */ |
| MVTWSI_CONTROL_START = 0x00000020, |
| /* I2C enable */ |
| MVTWSI_CONTROL_TWSIEN = 0x00000040, |
| /* Interrupt enable */ |
| MVTWSI_CONTROL_INTEN = 0x00000080, |
| }; |
| |
| /* |
| * On sun6i and newer, IFLG is a write-clear bit, which is cleared by writing 1; |
| * on other platforms, it is a normal r/w bit, which is cleared by writing 0. |
| */ |
| |
| #ifdef CONFIG_SUNXI_GEN_SUN6I |
| #define MVTWSI_CONTROL_CLEAR_IFLG 0x00000008 |
| #else |
| #define MVTWSI_CONTROL_CLEAR_IFLG 0x00000000 |
| #endif |
| |
| /* |
| * enum mvstwsi_status_values - Possible values of I2C controller's status |
| * register |
| * |
| * Only those statuses expected in normal master operation on |
| * non-10-bit-address devices are specified. |
| * |
| * Every status that's unexpected during normal operation (bus errors, |
| * arbitration losses, missing ACKs...) is passed back to the caller as an error |
| * code. |
| */ |
| enum mvstwsi_status_values { |
| /* START condition transmitted */ |
| MVTWSI_STATUS_START = 0x08, |
| /* Repeated START condition transmitted */ |
| MVTWSI_STATUS_REPEATED_START = 0x10, |
| /* Address + write bit transmitted, ACK received */ |
| MVTWSI_STATUS_ADDR_W_ACK = 0x18, |
| /* Data transmitted, ACK received */ |
| MVTWSI_STATUS_DATA_W_ACK = 0x28, |
| /* Address + read bit transmitted, ACK received */ |
| MVTWSI_STATUS_ADDR_R_ACK = 0x40, |
| /* Address + read bit transmitted, ACK not received */ |
| MVTWSI_STATUS_ADDR_R_NAK = 0x48, |
| /* Data received, ACK transmitted */ |
| MVTWSI_STATUS_DATA_R_ACK = 0x50, |
| /* Data received, ACK not transmitted */ |
| MVTWSI_STATUS_DATA_R_NAK = 0x58, |
| /* No relevant status */ |
| MVTWSI_STATUS_IDLE = 0xF8, |
| }; |
| |
| /* |
| * enum mvstwsi_ack_flags - Determine whether a read byte should be |
| * acknowledged or not. |
| */ |
| enum mvtwsi_ack_flags { |
| /* Send NAK after received byte */ |
| MVTWSI_READ_NAK = 0, |
| /* Send ACK after received byte */ |
| MVTWSI_READ_ACK = 1, |
| }; |
| |
| /* |
| * 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) { |
| #ifdef CONFIG_I2C_MVTWSI_BASE0 |
| case 0: |
| return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE0; |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE1 |
| case 1: |
| return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE1; |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE2 |
| case 2: |
| return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE2; |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE3 |
| case 3: |
| return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE3; |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE4 |
| case 4: |
| return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE4; |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE5 |
| case 5: |
| return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE5; |
| #endif |
| default: |
| printf("Missing mvtwsi controller %d base\n", adap->hwadapnr); |
| break; |
| } |
| |
| return NULL; |
| } |
| #endif |
| |
| /* |
| * enum mvtwsi_error_class - types of I2C errors |
| */ |
| enum mvtwsi_error_class { |
| /* The controller returned a different status than expected */ |
| MVTWSI_ERROR_WRONG_STATUS = 0x01, |
| /* The controller timed out */ |
| MVTWSI_ERROR_TIMEOUT = 0x02, |
| }; |
| |
| /* |
| * mvtwsi_error() - Build I2C return code from error information |
| * |
| * For debugging purposes, this function packs some information of an occurred |
| * error into a return code. These error codes are returned from I2C API |
| * functions (i2c_{read,write}, dm_i2c_{read,write}, etc.). |
| * |
| * @ec: The error class of the error (enum mvtwsi_error_class). |
| * @lc: The last value of the control register. |
| * @ls: The last value of the status register. |
| * @es: The expected value of the status register. |
| * @return The generated error code. |
| */ |
| inline uint mvtwsi_error(uint ec, uint lc, uint ls, uint es) |
| { |
| return ((ec << 24) & 0xFF000000) |
| | ((lc << 16) & 0x00FF0000) |
| | ((ls << 8) & 0x0000FF00) |
| | (es & 0xFF); |
| } |
| |
| /* |
| * 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, |
| uint tick) |
| { |
| int control, status; |
| int timeout = 1000; |
| |
| do { |
| control = readl(&twsi->control); |
| if (control & MVTWSI_CONTROL_IFLG) { |
| /* |
| * On Armada 38x it seems that the controller works as |
| * if it first set the MVTWSI_CONTROL_IFLAG in the |
| * control register and only after that it changed the |
| * status register. |
| * This sometimes caused weird bugs which only appeared |
| * on selected I2C speeds and even then only sometimes. |
| * We therefore add here a simple ndealy(100), which |
| * seems to fix this weird bug. |
| */ |
| ndelay(100); |
| status = readl(&twsi->status); |
| if (status == expected_status) |
| return 0; |
| else |
| return mvtwsi_error( |
| MVTWSI_ERROR_WRONG_STATUS, |
| control, status, expected_status); |
| } |
| ndelay(tick); /* One clock cycle */ |
| } while (timeout--); |
| status = readl(&twsi->status); |
| return mvtwsi_error(MVTWSI_ERROR_TIMEOUT, control, status, |
| expected_status); |
| } |
| |
| /* |
| * 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, |
| 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, tick); |
| } |
| |
| /* |
| * 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, uint tick) |
| { |
| /* Write byte to data register for sending */ |
| writel(byte, &twsi->data); |
| /* Clear any pending interrupt -- that will cause sending */ |
| 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, tick); |
| } |
| |
| /* |
| * 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, |
| uint tick) |
| { |
| int expected_status, status, control; |
| |
| /* Compute expected status based on passed ACK flag */ |
| expected_status = ack_flag ? MVTWSI_STATUS_DATA_R_ACK : |
| MVTWSI_STATUS_DATA_R_NAK; |
| /* Acknowledge *previous state*, and launch receive */ |
| control = MVTWSI_CONTROL_TWSIEN; |
| 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, tick); |
| /* If we did receive the expected byte, store it */ |
| if (status == 0) |
| *byte = readl(&twsi->data); |
| return status; |
| } |
| |
| /* |
| * 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, uint tick) |
| { |
| int control, stop_status; |
| int status = 0; |
| int timeout = 1000; |
| |
| /* Assert STOP */ |
| control = MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_STOP; |
| writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control); |
| /* Wait for IDLE; IFLG won't rise, so we can't use twsi_wait() */ |
| do { |
| stop_status = readl(&twsi->status); |
| if (stop_status == MVTWSI_STATUS_IDLE) |
| break; |
| ndelay(tick); /* One clock cycle */ |
| } while (timeout--); |
| control = readl(&twsi->control); |
| if (stop_status != MVTWSI_STATUS_IDLE) |
| status = mvtwsi_error(MVTWSI_ERROR_TIMEOUT, |
| control, status, MVTWSI_STATUS_IDLE); |
| 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_ARCH_SUNXI |
| return CONFIG_SYS_TCLK / (10 * (m + 1) * (1 << n)); |
| #else |
| return CONFIG_SYS_TCLK / (10 * (m + 1) * (2 << n)); |
| #endif |
| } |
| |
| /* |
| * 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) |
| { |
| /* Reset controller */ |
| writel(0, &twsi->soft_reset); |
| /* Wait 2 ms -- this is what the Marvell LSP does */ |
| udelay(20000); |
| } |
| |
| /* |
| * __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) |
| { |
| uint tmp_speed, highest_speed, n, m; |
| uint baud = 0x44; /* Baud rate after controller reset */ |
| |
| highest_speed = 0; |
| /* Successively try m, n combinations, and use the combination |
| * resulting in the largest speed that's not above the requested |
| * speed */ |
| for (n = 0; n < 8; n++) { |
| for (m = 0; m < 16; m++) { |
| tmp_speed = twsi_calc_freq(n, m); |
| if ((tmp_speed <= requested_speed) && |
| (tmp_speed > highest_speed)) { |
| highest_speed = tmp_speed; |
| baud = (m << 3) | n; |
| } |
| } |
| } |
| writel(baud, &twsi->baudrate); |
| |
| /* 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, uint *actual_speed) |
| { |
| uint tmp_speed; |
| |
| /* Reset controller */ |
| twsi_reset(twsi); |
| /* Set speed */ |
| tmp_speed = __twsi_i2c_set_bus_speed(twsi, speed); |
| if (actual_speed) |
| *actual_speed = tmp_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 */ |
| #ifdef CONFIG_DM_I2C |
| (void) twsi_stop(twsi, calc_tick(*actual_speed)); |
| #else |
| (void) twsi_stop(twsi, 10000); |
| #endif |
| } |
| |
| /* |
| * 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, uint tick) |
| { |
| int status, expected_addr_status; |
| |
| /* Compute the expected address status from the direction bit in |
| * the address byte */ |
| if (addr & 1) /* Reading */ |
| expected_addr_status = MVTWSI_STATUS_ADDR_R_ACK; |
| else /* Writing */ |
| expected_addr_status = MVTWSI_STATUS_ADDR_W_ACK; |
| /* Assert START */ |
| 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, tick); |
| /* Return 0, or the status of the first failure */ |
| return status; |
| } |
| |
| /* |
| * __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, |
| uint tick) |
| { |
| u8 dummy_byte; |
| int status; |
| |
| /* Begin i2c read */ |
| 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, tick); |
| /* Stop transaction */ |
| twsi_stop(twsi, tick); |
| /* Return 0, or the status of the first failure */ |
| return status; |
| } |
| |
| /* |
| * __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, |
| uint tick) |
| { |
| int status = 0; |
| int stop_status; |
| 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, 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, tick); |
| /* Stop transaction */ |
| stop_status = twsi_stop(twsi, tick); |
| /* Return 0, or the status of the first failure */ |
| return status != 0 ? status : stop_status; |
| } |
| |
| /* |
| * __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, |
| 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), tick); |
| /* Send address bytes */ |
| while ((status == 0) && (alen-- > 0)) |
| 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, |
| tick); |
| /* Stop transaction */ |
| stop_status = twsi_stop(twsi, tick); |
| /* Return 0, or the status of the first failure */ |
| return status != 0 ? status : stop_status; |
| } |
| |
| #ifndef CONFIG_DM_I2C |
| 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, NULL); |
| } |
| |
| static uint twsi_i2c_set_bus_speed(struct i2c_adapter *adap, |
| uint requested_speed) |
| { |
| struct mvtwsi_registers *twsi = twsi_get_base(adap); |
| __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, 10000); |
| } |
| |
| static int twsi_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr, |
| int alen, uchar *data, int length) |
| { |
| struct mvtwsi_registers *twsi = twsi_get_base(adap); |
| u8 addr_bytes[4]; |
| |
| addr_bytes[0] = (addr >> 0) & 0xFF; |
| addr_bytes[1] = (addr >> 8) & 0xFF; |
| addr_bytes[2] = (addr >> 16) & 0xFF; |
| addr_bytes[3] = (addr >> 24) & 0xFF; |
| |
| 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, |
| int alen, uchar *data, int length) |
| { |
| struct mvtwsi_registers *twsi = twsi_get_base(adap); |
| u8 addr_bytes[4]; |
| |
| addr_bytes[0] = (addr >> 0) & 0xFF; |
| addr_bytes[1] = (addr >> 8) & 0xFF; |
| addr_bytes[2] = (addr >> 16) & 0xFF; |
| addr_bytes[3] = (addr >> 24) & 0xFF; |
| |
| return __twsi_i2c_write(twsi, chip, addr_bytes, alen, data, length, |
| 10000); |
| } |
| |
| #ifdef CONFIG_I2C_MVTWSI_BASE0 |
| U_BOOT_I2C_ADAP_COMPLETE(twsi0, twsi_i2c_init, twsi_i2c_probe, |
| twsi_i2c_read, twsi_i2c_write, |
| twsi_i2c_set_bus_speed, |
| CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0) |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE1 |
| U_BOOT_I2C_ADAP_COMPLETE(twsi1, twsi_i2c_init, twsi_i2c_probe, |
| twsi_i2c_read, twsi_i2c_write, |
| twsi_i2c_set_bus_speed, |
| CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 1) |
| |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE2 |
| U_BOOT_I2C_ADAP_COMPLETE(twsi2, twsi_i2c_init, twsi_i2c_probe, |
| twsi_i2c_read, twsi_i2c_write, |
| twsi_i2c_set_bus_speed, |
| CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 2) |
| |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE3 |
| U_BOOT_I2C_ADAP_COMPLETE(twsi3, twsi_i2c_init, twsi_i2c_probe, |
| twsi_i2c_read, twsi_i2c_write, |
| twsi_i2c_set_bus_speed, |
| CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 3) |
| |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE4 |
| U_BOOT_I2C_ADAP_COMPLETE(twsi4, twsi_i2c_init, twsi_i2c_probe, |
| twsi_i2c_read, twsi_i2c_write, |
| twsi_i2c_set_bus_speed, |
| CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 4) |
| |
| #endif |
| #ifdef CONFIG_I2C_MVTWSI_BASE5 |
| U_BOOT_I2C_ADAP_COMPLETE(twsi5, twsi_i2c_init, twsi_i2c_probe, |
| twsi_i2c_read, twsi_i2c_write, |
| twsi_i2c_set_bus_speed, |
| CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 5) |
| |
| #endif |
| #else /* CONFIG_DM_I2C */ |
| |
| 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, dev->tick); |
| } |
| |
| static int mvtwsi_i2c_set_bus_speed(struct udevice *bus, uint speed) |
| { |
| struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); |
| |
| 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) |
| { |
| struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); |
| |
| dev->base = devfdt_get_addr_ptr(bus); |
| |
| if (!dev->base) |
| return -ENOMEM; |
| |
| dev->index = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus), |
| "cell-index", -1); |
| 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, dev_of_offset(bus), |
| "clock-frequency", 100000); |
| return 0; |
| } |
| |
| static void twsi_disable_i2c_slave(struct mvtwsi_registers *twsi) |
| { |
| clrbits_le32(&twsi->debug, BIT(18)); |
| } |
| |
| static int mvtwsi_i2c_bind(struct udevice *bus) |
| { |
| struct mvtwsi_registers *twsi = devfdt_get_addr_ptr(bus); |
| |
| /* Disable the hidden slave in i2c0 of these platforms */ |
| if ((IS_ENABLED(CONFIG_ARMADA_38X) || IS_ENABLED(CONFIG_KIRKWOOD)) |
| && bus->req_seq == 0) |
| twsi_disable_i2c_slave(twsi); |
| |
| return 0; |
| } |
| |
| static int mvtwsi_i2c_probe(struct udevice *bus) |
| { |
| struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); |
| 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; |
| } |
| |
| static int mvtwsi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) |
| { |
| struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); |
| struct i2c_msg *dmsg, *omsg, dummy; |
| |
| memset(&dummy, 0, sizeof(struct i2c_msg)); |
| |
| /* We expect either two messages (one with an offset and one with the |
| * actual data) or one message (just data or offset/data combined) */ |
| if (nmsgs > 2 || nmsgs == 0) { |
| debug("%s: Only one or two messages are supported.", __func__); |
| return -1; |
| } |
| |
| omsg = nmsgs == 1 ? &dummy : msg; |
| dmsg = nmsgs == 1 ? msg : msg + 1; |
| |
| if (dmsg->flags & I2C_M_RD) |
| return __twsi_i2c_read(dev->base, dmsg->addr, omsg->buf, |
| 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, |
| dev->tick); |
| } |
| |
| static const struct dm_i2c_ops mvtwsi_i2c_ops = { |
| .xfer = mvtwsi_i2c_xfer, |
| .probe_chip = mvtwsi_i2c_probe_chip, |
| .set_bus_speed = mvtwsi_i2c_set_bus_speed, |
| }; |
| |
| static const struct udevice_id mvtwsi_i2c_ids[] = { |
| { .compatible = "marvell,mv64xxx-i2c", }, |
| { .compatible = "marvell,mv78230-i2c", }, |
| { .compatible = "allwinner,sun6i-a31-i2c", }, |
| { /* sentinel */ } |
| }; |
| |
| U_BOOT_DRIVER(i2c_mvtwsi) = { |
| .name = "i2c_mvtwsi", |
| .id = UCLASS_I2C, |
| .of_match = mvtwsi_i2c_ids, |
| .bind = mvtwsi_i2c_bind, |
| .probe = mvtwsi_i2c_probe, |
| .ofdata_to_platdata = mvtwsi_i2c_ofdata_to_platdata, |
| .priv_auto_alloc_size = sizeof(struct mvtwsi_i2c_dev), |
| .ops = &mvtwsi_i2c_ops, |
| }; |
| #endif /* CONFIG_DM_I2C */ |