diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-sibyte.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-sibyte.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-sibyte.c b/drivers/i2c/busses/i2c-sibyte.c new file mode 100644 index 000000000..8f71f01cb --- /dev/null +++ b/drivers/i2c/busses/i2c-sibyte.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2004 Steven J. Hill + * Copyright (C) 2001,2002,2003 Broadcom Corporation + * Copyright (C) 1995-2000 Simon G. Vogl + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/io.h> +#include <asm/sibyte/sb1250_regs.h> +#include <asm/sibyte/sb1250_smbus.h> + + +struct i2c_algo_sibyte_data { + void *data; /* private data */ + int bus; /* which bus */ + void *reg_base; /* CSR base */ +}; + +/* ----- global defines ----------------------------------------------- */ +#define SMB_CSR(a,r) ((long)(a->reg_base + r)) + + +static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data * data) +{ + struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; + int data_bytes = 0; + int error; + + while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) + ; + + switch (size) { + case I2C_SMBUS_QUICK: + csr_out32((V_SMB_ADDR(addr) | + (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) | + V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START)); + break; + case I2C_SMBUS_BYTE: + if (read_write == I2C_SMBUS_READ) { + csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE), + SMB_CSR(adap, R_SMB_START)); + data_bytes = 1; + } else { + csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); + csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE), + SMB_CSR(adap, R_SMB_START)); + } + break; + case I2C_SMBUS_BYTE_DATA: + csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); + if (read_write == I2C_SMBUS_READ) { + csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE), + SMB_CSR(adap, R_SMB_START)); + data_bytes = 1; + } else { + csr_out32(V_SMB_LB(data->byte), + SMB_CSR(adap, R_SMB_DATA)); + csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), + SMB_CSR(adap, R_SMB_START)); + } + break; + case I2C_SMBUS_WORD_DATA: + csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); + if (read_write == I2C_SMBUS_READ) { + csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE), + SMB_CSR(adap, R_SMB_START)); + data_bytes = 2; + } else { + csr_out32(V_SMB_LB(data->word & 0xff), + SMB_CSR(adap, R_SMB_DATA)); + csr_out32(V_SMB_MB(data->word >> 8), + SMB_CSR(adap, R_SMB_DATA)); + csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), + SMB_CSR(adap, R_SMB_START)); + } + break; + default: + return -EOPNOTSUPP; + } + + while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) + ; + + error = csr_in32(SMB_CSR(adap, R_SMB_STATUS)); + if (error & M_SMB_ERROR) { + /* Clear error bit by writing a 1 */ + csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS)); + return (error & M_SMB_ERROR_TYPE) ? -EIO : -ENXIO; + } + + if (data_bytes == 1) + data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff; + if (data_bytes == 2) + data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff; + + return 0; +} + +static u32 bit_func(struct i2c_adapter *adap) +{ + return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA); +} + + +/* -----exported algorithm data: ------------------------------------- */ + +static const struct i2c_algorithm i2c_sibyte_algo = { + .smbus_xfer = smbus_xfer, + .functionality = bit_func, +}; + +/* + * registering functions to load algorithms at runtime + */ +static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed) +{ + struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; + + /* Register new adapter to i2c module... */ + i2c_adap->algo = &i2c_sibyte_algo; + + /* Set the requested frequency. */ + csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ)); + csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL)); + + return i2c_add_numbered_adapter(i2c_adap); +} + + +static struct i2c_algo_sibyte_data sibyte_board_data[2] = { + { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) }, + { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) } +}; + +static struct i2c_adapter sibyte_board_adapter[2] = { + { + .owner = THIS_MODULE, + .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, + .algo = NULL, + .algo_data = &sibyte_board_data[0], + .nr = 0, + .name = "SiByte SMBus 0", + }, + { + .owner = THIS_MODULE, + .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, + .algo = NULL, + .algo_data = &sibyte_board_data[1], + .nr = 1, + .name = "SiByte SMBus 1", + }, +}; + +static int __init i2c_sibyte_init(void) +{ + pr_info("i2c-sibyte: i2c SMBus adapter module for SiByte board\n"); + if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0) + return -ENODEV; + if (i2c_sibyte_add_bus(&sibyte_board_adapter[1], + K_SMB_FREQ_400KHZ) < 0) { + i2c_del_adapter(&sibyte_board_adapter[0]); + return -ENODEV; + } + return 0; +} + +static void __exit i2c_sibyte_exit(void) +{ + i2c_del_adapter(&sibyte_board_adapter[0]); + i2c_del_adapter(&sibyte_board_adapter[1]); +} + +module_init(i2c_sibyte_init); +module_exit(i2c_sibyte_exit); + +MODULE_AUTHOR("Kip Walker (Broadcom Corp.)"); +MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>"); +MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards"); +MODULE_LICENSE("GPL"); |