diff options
Diffstat (limited to 'drivers/i2c/u8500_i2c.c')
| -rw-r--r-- | drivers/i2c/u8500_i2c.c | 601 |
1 files changed, 0 insertions, 601 deletions
diff --git a/drivers/i2c/u8500_i2c.c b/drivers/i2c/u8500_i2c.c deleted file mode 100644 index 81ffb8e..0000000 --- a/drivers/i2c/u8500_i2c.c +++ /dev/null @@ -1,601 +0,0 @@ -/* - * Copyright (C) ST-Ericsson SA 2010 - * - * Basic U-Boot I2C interface for STn8500/DB8500 - * Author: Michael Brandt <Michael.Brandt@stericsson.com> for ST-Ericsson - * - * SPDX-License-Identifier: GPL-2.0+ - */ - -/* - * Only 7-bit I2C device addresses are supported. - */ - -#include <common.h> -#include <i2c.h> - -#include "u8500_i2c.h" -#include <asm/io.h> -#include <asm/arch/clock.h> - -#define U8500_I2C_ENDAD_COUNTER (CONFIG_SYS_HZ/100) /* I2C bus timeout */ -#define U8500_I2C_FIFO_FLUSH_COUNTER 500000 /* flush "timeout" */ -#define U8500_I2C_SCL_FREQ 100000 /* I2C bus clock freq */ -#define U8500_I2C_INPUT_FREQ 48000000 /* Input clock freq */ -#define TX_FIFO_THRESHOLD 0x4 -#define RX_FIFO_THRESHOLD 0x4 -#define SLAVE_SETUP_TIME 14 /* Slave data setup time, 250ns for 48MHz i2c_clk */ - -#define WRITE_FIELD(var, mask, shift, value) \ - (var = ((var & ~(mask)) | ((value) << (shift)))) - -static unsigned int bus_initialized[CONFIG_SYS_U8500_I2C_BUS_MAX]; -static unsigned int i2c_bus_num; -static unsigned int i2c_bus_speed[] = { - CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SPEED, - CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SPEED -}; -static struct u8500_i2c_regs *i2c_dev[] = { - (struct u8500_i2c_regs *)CONFIG_SYS_U8500_I2C0_BASE, - (struct u8500_i2c_regs *)CONFIG_SYS_U8500_I2C1_BASE, - (struct u8500_i2c_regs *)CONFIG_SYS_U8500_I2C2_BASE, - (struct u8500_i2c_regs *)CONFIG_SYS_U8500_I2C3_BASE, -}; - -static struct { - int periph; - int pcken; - int kcken; -} i2c_clock_bits[] = { - {3, 3, 3}, /* I2C0 */ - {1, 2, 2}, /* I2C1 */ - {1, 6, 6}, /* I2C2 */ - {2, 0, 0}, /* I2C3 */ -}; - -static void i2c_set_bit(void *reg, u32 mask) -{ - writel(readl(reg) | mask, reg); -} - -static void i2c_clr_bit(void *reg, u32 mask) -{ - writel(readl(reg) & ~mask, reg); -} - -static void i2c_write_field(void *reg, u32 mask, uint shift, u32 value) -{ - writel((readl(reg) & ~mask) | (value << shift), reg); -} - -static int __i2c_set_bus_speed(unsigned int speed) -{ - u32 value; - struct u8500_i2c_regs *i2c_regs; - - i2c_regs = i2c_dev[i2c_bus_num]; - - /* Select standard (100 kbps) speed mode */ - i2c_write_field(&i2c_regs->cr, U8500_I2C_CR_SM, - U8500_I2C_CR_SHIFT_SM, 0x0); - - /* - * Set the Baud Rate Counter 2 value - * Baud rate (standard) = fi2cclk / ( (BRCNT2 x 2) + Foncycle ) - * Foncycle = 0 (no digital filtering) - */ - value = (u32) (U8500_I2C_INPUT_FREQ / (speed * 2)); - i2c_write_field(&i2c_regs->brcr, U8500_I2C_BRCR_BRCNT2, - U8500_I2C_BRCR_SHIFT_BRCNT2, value); - - /* ensure that BRCNT value is zero */ - i2c_write_field(&i2c_regs->brcr, U8500_I2C_BRCR_BRCNT1, - U8500_I2C_BRCR_SHIFT_BRCNT1, 0); - - return U8500_I2C_INPUT_FREQ/(value * 2); -} - -/* - * i2c_init - initialize the i2c bus - * - * speed: bus speed (in HZ) - * slaveaddr: address of device in slave mode - * - * Slave mode is not implemented. - */ -void i2c_init(int speed, int slaveaddr) -{ - struct u8500_i2c_regs *i2c_regs; - - debug("i2c_init bus %d, speed %d\n", i2c_bus_num, speed); - - u8500_clock_enable(i2c_clock_bits[i2c_bus_num].periph, - i2c_clock_bits[i2c_bus_num].pcken, - i2c_clock_bits[i2c_bus_num].kcken); - - i2c_regs = i2c_dev[i2c_bus_num]; - - /* Disable the controller */ - i2c_clr_bit(&i2c_regs->cr, U8500_I2C_CR_PE); - - /* Clear registers */ - writel(0, &i2c_regs->cr); - writel(0, &i2c_regs->scr); - writel(0, &i2c_regs->hsmcr); - writel(0, &i2c_regs->tftr); - writel(0, &i2c_regs->rftr); - writel(0, &i2c_regs->dmar); - - i2c_bus_speed[i2c_bus_num] = __i2c_set_bus_speed(speed); - - /* - * Set our own address. - * Set slave address mode to 7 bit addressing mode - */ - i2c_clr_bit(&i2c_regs->cr, U8500_I2C_CR_SAM); - i2c_write_field(&i2c_regs->scr, U8500_I2C_SCR_ADDR, - U8500_I2C_SCR_SHIFT_ADDR, slaveaddr); - /* Slave Data Set up Time */ - i2c_write_field(&i2c_regs->scr, U8500_I2C_SCR_DATA_SETUP_TIME, - U8500_I2C_SCR_SHIFT_DATA_SETUP_TIME, SLAVE_SETUP_TIME); - - /* Disable the DMA sync logic */ - i2c_write_field(&i2c_regs->cr, U8500_I2C_CR_DMA_SLE, - U8500_I2C_CR_SHIFT_DMA_SLE, 0); - - /* Disable interrupts */ - writel(0, &i2c_regs->imscr); - - /* Configure bus master mode */ - i2c_write_field(&i2c_regs->cr, U8500_I2C_CR_OM, U8500_I2C_CR_SHIFT_OM, - U8500_I2C_BUS_MASTER_MODE); - /* Set FIFO threshold values */ - writel(TX_FIFO_THRESHOLD, &i2c_regs->tftr); - writel(RX_FIFO_THRESHOLD, &i2c_regs->rftr); - - /* Enable the I2C Controller */ - i2c_set_bit(&i2c_regs->cr, U8500_I2C_CR_PE); - - bus_initialized[i2c_bus_num] = 1; -} - - -/* - * loop_till_bit_clear - polls on a bit till it clears - * ioreg: register where you want to check status - * mask: bit mask for the bit you wish to check - * timeout: timeout in ticks/s - */ -static int loop_till_bit_clear(void *io_reg, u32 mask, unsigned long timeout) -{ - unsigned long timebase = get_timer(0); - - do { - if ((readl(io_reg) & mask) == 0x0UL) - return 0; - } while (get_timer(timebase) < timeout); - - debug("loop_till_bit_clear timed out\n"); - return -1; -} - -/* - * loop_till_bit_set - polls on a bit till it is set. - * ioreg: register where you want to check status - * mask: bit mask for the bit you wish to check - * timeout: timeout in ticks/s - */ -static int loop_till_bit_set(void *io_reg, u32 mask, unsigned long timeout) -{ - unsigned long timebase = get_timer(0); - - do { - if ((readl(io_reg) & mask) != 0x0UL) - return 0; - } while (get_timer(timebase) < timeout); - - debug("loop_till_bit_set timed out\n"); - return -1; -} - -/* - * flush_fifo - flush the I2C TX and RX FIFOs - */ -static void flush_fifo(struct u8500_i2c_regs *i2c_regs) -{ - int counter = U8500_I2C_FIFO_FLUSH_COUNTER; - - /* Flush Tx FIFO */ - i2c_set_bit(&i2c_regs->cr, U8500_I2C_CR_FTX); - /* Flush Rx FIFO */ - i2c_set_bit(&i2c_regs->cr, U8500_I2C_CR_FRX); - while (counter--) { - if (!(readl(&i2c_regs->cr) & - (U8500_I2C_CR_FTX | U8500_I2C_CR_FRX))) - break; - } - return; -} - -#ifdef DEBUG -static void print_abort_reason(struct u8500_i2c_regs *i2c_regs) -{ - int cause; - - printf("abort: risr %08x, sr %08x\n", i2c_regs->risr, i2c_regs->sr); - cause = (readl(&i2c_regs->sr) & U8500_I2C_SR_CAUSE) >> - U8500_I2C_SR_SHIFT_CAUSE; - switch (cause) { - case U8500_I2C_NACK_ADDR: - printf("No Ack received after Slave Address xmission\n"); - break; - case U8500_I2C_NACK_DATA: - printf("Valid for MASTER_WRITE: No Ack received " - "during data phase\n"); - break; - case U8500_I2C_ACK_MCODE: - printf("Master recv ack after xmission of master code" - "in hs mode\n"); - break; - case U8500_I2C_ARB_LOST: - printf("Master Lost arbitration\n"); - break; - case U8500_I2C_BERR_START: - printf("Slave restarts\n"); - break; - case U8500_I2C_BERR_STOP: - printf("Slave reset\n"); - break; - case U8500_I2C_OVFL: - printf("Overflow\n"); - break; - default: - printf("Unknown error type\n"); - } -} -#endif - -/* - * i2c_abort - called when a I2C transaction failed - */ -static void i2c_abort(struct u8500_i2c_regs *i2c_regs) -{ -#ifdef DEBUG - print_abort_reason(i2c_regs); -#endif - /* flush RX and TX fifos */ - flush_fifo(i2c_regs); - - /* Acknowledge the Master Transaction Done */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTD); - - /* Acknowledge the Master Transaction Done Without Stop */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTDWS); - - i2c_init(i2c_bus_speed[i2c_bus_num], CONFIG_SYS_I2C_SLAVE); -} - -/* - * write addr, alias index, to I2C bus. - */ -static int i2c_write_addr(struct u8500_i2c_regs *i2c_regs, uint addr, int alen) -{ - while (alen--) { - /* Wait until the Tx Fifo is not full */ - if (loop_till_bit_clear((void *)&i2c_regs->risr, - U8500_I2C_INT_TXFF, - U8500_I2C_ENDAD_COUNTER)) { - i2c_abort(i2c_regs); - return -1; - } - - /* MSB first */ - writeb((addr >> (alen * 8)) & 0xff, &i2c_regs->tfr); - } - - return 0; -} - -/* - * Internal simplified read function: - * i2c_regs: Pointer to I2C registers for current bus - * chip: I2C chip address, range 0..127 - * addr: Memory (register) address within the chip - * alen: Number of bytes to use for addr (typically 1, 2 for larger - * memories, 0 for register type devices with only one register) - * value: Where to put the data - * - * Returns: 0 on success, not 0 on failure - */ -static int i2c_read_byte(struct u8500_i2c_regs *i2c_regs, uchar chip, - uint addr, int alen, uchar *value) -{ - u32 mcr = 0; - - /* Set the address mode to 7 bit */ - WRITE_FIELD(mcr, U8500_I2C_MCR_AM, U8500_I2C_MCR_SHIFT_AM, 1); - - /* Store the slave address in the master control register */ - WRITE_FIELD(mcr, U8500_I2C_MCR_A7, U8500_I2C_MCR_SHIFT_A7, chip); - - if (alen != 0) { - /* Master write operation */ - mcr &= ~(U8500_I2C_MCR_OP); - - /* Configure the Frame length to one byte */ - WRITE_FIELD(mcr, U8500_I2C_MCR_LENGTH, - U8500_I2C_MCR_SHIFT_LENGTH, 1); - - /* Repeated start, no stop */ - mcr &= ~(U8500_I2C_MCR_STOP); - - /* Write Master Control Register */ - writel(mcr, &i2c_regs->mcr); - - /* send addr/index */ - if (i2c_write_addr(i2c_regs, addr, alen) != 0) - return -1; - - /* Check for the Master Transaction Done Without Stop */ - if (loop_till_bit_set((void *)&i2c_regs->risr, - U8500_I2C_INT_MTDWS, - U8500_I2C_ENDAD_COUNTER)) { - return -1; - } - - /* Acknowledge the Master Transaction Done Without Stop */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTDWS); - } - - /* Master control configuration for read operation */ - mcr |= U8500_I2C_MCR_OP; - - /* Configure the STOP condition, we read only one byte */ - mcr |= U8500_I2C_MCR_STOP; - - /* Set the frame length to one byte, we support only 1 byte reads */ - WRITE_FIELD(mcr, U8500_I2C_MCR_LENGTH, U8500_I2C_MCR_SHIFT_LENGTH, 1); - - i2c_write_field(&i2c_regs->mcr, U8500_I2C_MCR_LENGTH_STOP_OP, - U8500_I2C_MCR_SHIFT_LENGTH_STOP_OP, mcr); - - /* - * receive_data_polling - */ - - /* Wait until the Rx FIFO is not empty */ - if (loop_till_bit_clear((void *)&i2c_regs->risr, - U8500_I2C_INT_RXFE, - U8500_I2C_ENDAD_COUNTER)) - return -1; - - /* Read the data byte from Rx FIFO */ - *value = readb(&i2c_regs->rfr); - - /* Wait until the work is done */ - if (loop_till_bit_set((void *)&i2c_regs->risr, U8500_I2C_INT_MTD, - U8500_I2C_ENDAD_COUNTER)) - return -1; - - /* Acknowledge the Master Transaction Done */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTD); - - /* If MTD is set, Master Transaction Done Without Stop is set too */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTDWS); - - return 0; -} - -/* - * Internal simplified write function: - * i2c_regs: Pointer to I2C registers for current bus - * chip: I2C chip address, range 0..127 - * addr: Memory (register) address within the chip - * alen: Number of bytes to use for addr (typically 1, 2 for larger - * memories, 0 for register type devices with only one register) - * data: Where to read the data - * len: How many bytes to write - * - * Returns: 0 on success, not 0 on failure - */ -static int __i2c_write(struct u8500_i2c_regs *i2c_regs, u8 chip, uint addr, - int alen, u8 *data, int len) -{ - int i; - u32 mcr = 0; - - /* Set the address mode to 7 bit */ - WRITE_FIELD(mcr, U8500_I2C_MCR_AM, U8500_I2C_MCR_SHIFT_AM, 1); - - /* Store the slave address in the master control register */ - WRITE_FIELD(mcr, U8500_I2C_MCR_A7, U8500_I2C_MCR_SHIFT_A7, chip); - - /* Write operation */ - mcr &= ~(U8500_I2C_MCR_OP); - - /* Current transaction is terminated by STOP condition */ - mcr |= U8500_I2C_MCR_STOP; - - /* Frame length: addr byte + len */ - WRITE_FIELD(mcr, U8500_I2C_MCR_LENGTH, U8500_I2C_MCR_SHIFT_LENGTH, - (alen + len)); - - /* Write MCR register */ - writel(mcr, &i2c_regs->mcr); - - if (i2c_write_addr(i2c_regs, addr, alen) != 0) - return -1; - - for (i = 0; i < len; i++) { - /* Wait until the Tx FIFO is not full */ - if (loop_till_bit_clear((void *)&i2c_regs->risr, - U8500_I2C_INT_TXFF, - U8500_I2C_ENDAD_COUNTER)) - return -1; - - /* it is a 32 bit register with upper 24 reserved R/O */ - writeb(data[i], &i2c_regs->tfr); - } - - /* Check for Master Transaction Done */ - if (loop_till_bit_set((void *)&i2c_regs->risr, - U8500_I2C_INT_MTD, - U8500_I2C_ENDAD_COUNTER)) { - printf("i2c_write_byte error2: risr %08x\n", - i2c_regs->risr); - return -1; - } - - /* Acknowledge Master Transaction Done */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTD); - - /* Acknowledge Master Transaction Done Without Stop */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTDWS); - - return 0; -} - -/* - * Probe the given I2C chip address. Returns 0 if a chip responded, - * not 0 on failure. - */ -int i2c_probe(uchar chip) -{ - u32 mcr = 0; - struct u8500_i2c_regs *i2c_regs; - - if (chip == CONFIG_SYS_I2C_SLAVE) - return 1; - - i2c_regs = i2c_dev[i2c_bus_num]; - - /* Set the address mode to 7 bit */ - WRITE_FIELD(mcr, U8500_I2C_MCR_AM, U8500_I2C_MCR_SHIFT_AM, 1); - - /* Store the slave address in the master control register */ - WRITE_FIELD(mcr, U8500_I2C_MCR_A10, U8500_I2C_MCR_SHIFT_A7, chip); - - /* Read operation */ - mcr |= U8500_I2C_MCR_OP; - - /* Set the frame length to one byte */ - WRITE_FIELD(mcr, U8500_I2C_MCR_LENGTH, U8500_I2C_MCR_SHIFT_LENGTH, 1); - - /* Current transaction is terminated by STOP condition */ - mcr |= U8500_I2C_MCR_STOP; - - /* Write MCR register */ - writel(mcr, &i2c_regs->mcr); - - /* Wait until the Rx Fifo is not empty */ - if (loop_till_bit_clear((void *)&i2c_regs->risr, - U8500_I2C_INT_RXFE, - U8500_I2C_ENDAD_COUNTER)) { - i2c_abort(i2c_regs); - return -1; - } - - flush_fifo(i2c_regs); - - /* Acknowledge the Master Transaction Done */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTD); - - /* Acknowledge the Master Transaction Done Without Stop */ - i2c_set_bit(&i2c_regs->icr, U8500_I2C_INT_MTDWS); - - return 0; -} - -/* - * Read/Write interface: - * chip: I2C chip address, range 0..127 - * addr: Memory (register) address within the chip - * alen: Number of bytes to use for addr (typically 1, 2 for larger - * memories, 0 for register type devices with only one - * register) - * buffer: Where to read/write the data - * len: How many bytes to read/write - * - * Returns: 0 on success, not 0 on failure - */ -int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) -{ - int i; - int rc; - struct u8500_i2c_regs *i2c_regs; - - if (alen > 2) { - debug("I2C read: addr len %d not supported\n", alen); - return 1; - } - - i2c_regs = i2c_dev[i2c_bus_num]; - - for (i = 0; i < len; i++) { - rc = i2c_read_byte(i2c_regs, chip, addr + i, alen, &buffer[i]); - if (rc != 0) { - debug("I2C read: I/O error: %d\n", rc); - i2c_abort(i2c_regs); - return rc; - } - } - - return 0; -} - -int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) -{ - int rc; - struct u8500_i2c_regs *i2c_regs; - i2c_regs = i2c_dev[i2c_bus_num]; - - rc = __i2c_write(i2c_regs, chip, addr, alen, buffer, - len); - if (rc != 0) { - debug("I2C write: I/O error\n"); - i2c_abort(i2c_regs); - return rc; - } - return 0; -} - -int i2c_set_bus_num(unsigned int bus) -{ - if (bus > ARRAY_SIZE(i2c_dev) - 1) { - debug("i2c_set_bus_num: only up to bus %d supported\n", - ARRAY_SIZE(i2c_dev)-1); - return -1; - } - - i2c_bus_num = bus; - - if (!bus_initialized[i2c_bus_num]) - i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); - - return 0; -} - -int i2c_set_bus_speed(unsigned int speed) -{ - - if (speed > U8500_I2C_MAX_STANDARD_SCL) { - debug("i2c_set_bus_speed: only up to %d supported\n", - U8500_I2C_MAX_STANDARD_SCL); - return -1; - } - - /* sets as side effect i2c_bus_speed[i2c_bus_num] */ - i2c_init(speed, CONFIG_SYS_I2C_SLAVE); - - return 0; -} - -unsigned int i2c_get_bus_num(void) -{ - return i2c_bus_num; -} - -unsigned int i2c_get_bus_speed(void) -{ - return i2c_bus_speed[i2c_bus_num]; -} |