diff options
Diffstat (limited to 'drivers/i2c/ihs_i2c.c')
| -rw-r--r-- | drivers/i2c/ihs_i2c.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/i2c/ihs_i2c.c b/drivers/i2c/ihs_i2c.c new file mode 100644 index 0000000..ecc5856 --- /dev/null +++ b/drivers/i2c/ihs_i2c.c @@ -0,0 +1,204 @@ +/* + * (C) Copyright 2013 + * Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <i2c.h> +#include <gdsys_fpga.h> + +DECLARE_GLOBAL_DATA_PTR; + +enum { + I2CINT_ERROR_EV = 1 << 13, + I2CINT_TRANSMIT_EV = 1 << 14, + I2CINT_RECEIVE_EV = 1 << 15, +}; + +enum { + I2CMB_WRITE = 1 << 10, + I2CMB_2BYTE = 1 << 11, + I2CMB_HOLD_BUS = 1 << 13, + I2CMB_NATIVE = 2 << 14, +}; + +static int wait_for_int(bool read) +{ + u16 val; + unsigned int ctr = 0; + + FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val); + while (!(val & (I2CINT_ERROR_EV + | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) { + udelay(10); + if (ctr++ > 5000) { + printf("I2C timeout\n"); + return 1; + } + FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val); + } + + return (val & I2CINT_ERROR_EV) ? 1 : 0; +} + +static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read, + bool is_last) +{ + u16 val; + + FPGA_SET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, I2CINT_ERROR_EV + | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV); + FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val); + + if (!read && len) { + val = buffer[0]; + + if (len > 1) + val |= buffer[1] << 8; + FPGA_SET_REG(I2C_ADAP_HWNR, i2c.write_mailbox_ext, val); + } + + FPGA_SET_REG(I2C_ADAP_HWNR, i2c.write_mailbox, + I2CMB_NATIVE + | (read ? 0 : I2CMB_WRITE) + | (chip << 1) + | ((len > 1) ? I2CMB_2BYTE : 0) + | (is_last ? 0 : I2CMB_HOLD_BUS)); + + if (wait_for_int(read)) + return 1; + + if (read) { + FPGA_GET_REG(I2C_ADAP_HWNR, i2c.read_mailbox_ext, &val); + buffer[0] = val & 0xff; + if (len > 1) + buffer[1] = val >> 8; + } + + return 0; +} + +static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus) +{ + int shift = (alen-1) * 8; + + while (alen) { + int transfer = MIN(alen, 2); + uchar buf[2]; + bool is_last = alen <= transfer; + + buf[0] = addr >> shift; + if (alen > 1) + buf[1] = addr >> (shift - 8); + + if (ihs_i2c_transfer(chip, buf, transfer, false, + hold_bus ? false : is_last)) + return 1; + + shift -= 16; + alen -= transfer; + } + + return 0; +} + +static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr, + int alen, uchar *buffer, int len, bool read) +{ + if (len <= 0) + return 1; + + if (ihs_i2c_address(chip, addr, alen, !read)) + return 1; + + while (len) { + int transfer = MIN(len, 2); + + if (ihs_i2c_transfer(chip, buffer, transfer, read, + len <= transfer)) + return 1; + + buffer += transfer; + addr += transfer; + len -= transfer; + } + + return 0; +} + + +static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr) +{ +#ifdef CONFIG_SYS_I2C_INIT_BOARD + /* + * Call board specific i2c bus reset routine before accessing the + * environment, which might be in a chip on that bus. For details + * about this problem see doc/I2C_Edge_Conditions. + */ + i2c_init_board(); +#endif +} + +static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip) +{ + uchar buffer[2]; + + if (ihs_i2c_transfer(chip, buffer, 0, true, true)) + return 1; + + return 0; +} + +static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr, + int alen, uchar *buffer, int len) +{ + return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true); +} + +static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr, + int alen, uchar *buffer, int len) +{ + return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false); +} + +static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap, + unsigned int speed) +{ + if (speed != adap->speed) + return 1; + return speed; +} + +/* + * Register IHS i2c adapters + */ +#ifdef CONFIG_SYS_I2C_IHS_CH0 +U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe, + ihs_i2c_read, ihs_i2c_write, + ihs_i2c_set_bus_speed, + CONFIG_SYS_I2C_IHS_SPEED_0, + CONFIG_SYS_I2C_IHS_SLAVE_0, 0) +#endif +#ifdef CONFIG_SYS_I2C_IHS_CH1 +U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe, + ihs_i2c_read, ihs_i2c_write, + ihs_i2c_set_bus_speed, + CONFIG_SYS_I2C_IHS_SPEED_1, + CONFIG_SYS_I2C_IHS_SLAVE_1, 1) +#endif +#ifdef CONFIG_SYS_I2C_IHS_CH2 +U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe, + ihs_i2c_read, ihs_i2c_write, + ihs_i2c_set_bus_speed, + CONFIG_SYS_I2C_IHS_SPEED_2, + CONFIG_SYS_I2C_IHS_SLAVE_2, 2) +#endif +#ifdef CONFIG_SYS_I2C_IHS_CH3 +U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe, + ihs_i2c_read, ihs_i2c_write, + ihs_i2c_set_bus_speed, + CONFIG_SYS_I2C_IHS_SPEED_3, + CONFIG_SYS_I2C_IHS_SLAVE_3, 3) +#endif |