diff options
Diffstat (limited to 'drivers/i2c/spr_i2c.c')
| -rwxr-xr-x | drivers/i2c/spr_i2c.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/i2c/spr_i2c.c b/drivers/i2c/spr_i2c.c new file mode 100755 index 0000000..eabfe84 --- /dev/null +++ b/drivers/i2c/spr_i2c.c @@ -0,0 +1,331 @@ +/* + * (C) Copyright 2009 + * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/hardware.h> +#include <asm/arch/spr_i2c.h> + +static struct i2c_regs *const i2c_regs_p = + (struct i2c_regs *)CONFIG_SYS_I2C_BASE; + +/* + * set_speed - Set the i2c speed mode (standard, high, fast) + * @i2c_spd: required i2c speed mode + * + * Set the i2c speed mode (standard, high, fast) + */ +static void set_speed(int i2c_spd) +{ + unsigned int cntl; + unsigned int hcnt, lcnt; + unsigned int high, low; + + cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK)); + + switch (i2c_spd) { + case IC_SPEED_MODE_MAX: + cntl |= IC_CON_SPD_HS; + high = MIN_HS_SCL_HIGHTIME; + low = MIN_HS_SCL_LOWTIME; + break; + + case IC_SPEED_MODE_STANDARD: + cntl |= IC_CON_SPD_SS; + high = MIN_SS_SCL_HIGHTIME; + low = MIN_SS_SCL_LOWTIME; + break; + + case IC_SPEED_MODE_FAST: + default: + cntl |= IC_CON_SPD_FS; + high = MIN_FS_SCL_HIGHTIME; + low = MIN_FS_SCL_LOWTIME; + break; + } + + writel(cntl, &i2c_regs_p->ic_con); + + hcnt = (IC_CLK * high) / NANO_TO_MICRO; + writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt); + + lcnt = (IC_CLK * low) / NANO_TO_MICRO; + writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt); +} + +/* + * i2c_set_bus_speed - Set the i2c speed + * @speed: required i2c speed + * + * Set the i2c speed. + */ +void i2c_set_bus_speed(int speed) +{ + if (speed >= I2C_MAX_SPEED) + set_speed(IC_SPEED_MODE_MAX); + else if (speed >= I2C_FAST_SPEED) + set_speed(IC_SPEED_MODE_FAST); + else + set_speed(IC_SPEED_MODE_STANDARD); +} + +/* + * i2c_get_bus_speed - Gets the i2c speed + * + * Gets the i2c speed. + */ +int i2c_get_bus_speed(void) +{ + u32 cntl; + + cntl = (readl(&i2c_regs_p->ic_con) & IC_CON_SPD_MSK); + + if (cntl == IC_CON_SPD_HS) + return I2C_MAX_SPEED; + else if (cntl == IC_CON_SPD_FS) + return I2C_FAST_SPEED; + else if (cntl == IC_CON_SPD_SS) + return I2C_STANDARD_SPEED; + + return 0; +} + +/* + * i2c_init - Init function + * @speed: required i2c speed + * @slaveadd: slave address for the spear device + * + * Initialization function. + */ +void i2c_init(int speed, int slaveadd) +{ + unsigned int enbl; + + /* Disable i2c */ + enbl = readl(&i2c_regs_p->ic_enable); + enbl &= ~IC_ENABLE_0B; + writel(enbl, &i2c_regs_p->ic_enable); + + writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_regs_p->ic_con); + writel(IC_RX_TL, &i2c_regs_p->ic_rx_tl); + writel(IC_TX_TL, &i2c_regs_p->ic_tx_tl); + i2c_set_bus_speed(speed); + writel(IC_STOP_DET, &i2c_regs_p->ic_intr_mask); + writel(slaveadd, &i2c_regs_p->ic_sar); + + /* Enable i2c */ + enbl = readl(&i2c_regs_p->ic_enable); + enbl |= IC_ENABLE_0B; + writel(enbl, &i2c_regs_p->ic_enable); +} + +/* + * i2c_setaddress - Sets the target slave address + * @i2c_addr: target i2c address + * + * Sets the target slave address. + */ +static void i2c_setaddress(unsigned int i2c_addr) +{ + writel(i2c_addr, &i2c_regs_p->ic_tar); +} + +/* + * i2c_flush_rxfifo - Flushes the i2c RX FIFO + * + * Flushes the i2c RX FIFO + */ +static void i2c_flush_rxfifo(void) +{ + while (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) + readl(&i2c_regs_p->ic_cmd_data); +} + +/* + * i2c_wait_for_bb - Waits for bus busy + * + * Waits for bus busy + */ +static int i2c_wait_for_bb(void) +{ + unsigned long start_time_bb = get_timer(0); + + while ((readl(&i2c_regs_p->ic_status) & IC_STATUS_MA) || + !(readl(&i2c_regs_p->ic_status) & IC_STATUS_TFE)) { + + /* Evaluate timeout */ + if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB)) + return 1; + } + + return 0; +} + +/* check parameters for i2c_read and i2c_write */ +static int check_params(uint addr, int alen, uchar *buffer, int len) +{ + if (buffer == NULL) { + printf("Buffer is invalid\n"); + return 1; + } + + if (alen > 1) { + printf("addr len %d not supported\n", alen); + return 1; + } + + if (addr + len > 256) { + printf("address out of range\n"); + return 1; + } + + return 0; +} + +static int i2c_xfer_init(uchar chip, uint addr) +{ + if (i2c_wait_for_bb()) { + printf("Timed out waiting for bus\n"); + return 1; + } + + i2c_setaddress(chip); + writel(addr, &i2c_regs_p->ic_cmd_data); + + return 0; +} + +static int i2c_xfer_finish(void) +{ + ulong start_stop_det = get_timer(0); + + while (1) { + if ((readl(&i2c_regs_p->ic_raw_intr_stat) & IC_STOP_DET)) { + readl(&i2c_regs_p->ic_clr_stop_det); + break; + } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) { + break; + } + } + + if (i2c_wait_for_bb()) { + printf("Timed out waiting for bus\n"); + return 1; + } + + i2c_flush_rxfifo(); + + /* Wait for read/write operation to complete on actual memory */ + udelay(10000); + + return 0; +} + +/* + * i2c_read - Read from i2c memory + * @chip: target i2c address + * @addr: address to read from + * @alen: + * @buffer: buffer for read data + * @len: no of bytes to be read + * + * Read from i2c memory. + */ +int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + unsigned long start_time_rx; + + if (check_params(addr, alen, buffer, len)) + return 1; + + if (i2c_xfer_init(chip, addr)) + return 1; + + start_time_rx = get_timer(0); + while (len) { + writel(IC_CMD, &i2c_regs_p->ic_cmd_data); + + if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) { + *buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data); + len--; + start_time_rx = get_timer(0); + + } else if (get_timer(start_time_rx) > I2C_BYTE_TO) { + printf("Timed out. i2c read Failed\n"); + return 1; + } + } + + return i2c_xfer_finish(); +} + +/* + * i2c_write - Write to i2c memory + * @chip: target i2c address + * @addr: address to read from + * @alen: + * @buffer: buffer for read data + * @len: no of bytes to be read + * + * Write to i2c memory. + */ +int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + int nb = len; + unsigned long start_time_tx; + + if (check_params(addr, alen, buffer, len)) + return 1; + + if (i2c_xfer_init(chip, addr)) + return 1; + + start_time_tx = get_timer(0); + while (len) { + if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) { + writel(*buffer, &i2c_regs_p->ic_cmd_data); + buffer++; + len--; + start_time_tx = get_timer(0); + + } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) { + printf("Timed out. i2c write Failed\n"); + return 1; + } + } + + return i2c_xfer_finish(); +} + +/* + * i2c_probe - Probe the i2c chip + */ +int i2c_probe(uchar chip) +{ + u32 tmp; + + /* + * Try to read the first location of the chip. + */ + return i2c_read(chip, 0, 1, (uchar *)&tmp, 1); +} |