diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-slave.c')
-rw-r--r-- | drivers/i2c/busses/i2c-designware-slave.c | 62 |
1 files changed, 11 insertions, 51 deletions
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c index 8ce2cd368477..e7f9305b2dd9 100644 --- a/drivers/i2c/busses/i2c-designware-slave.c +++ b/drivers/i2c/busses/i2c-designware-slave.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Synopsys DesignWare I2C adapter driver (slave only). * * Based on the Synopsys DesignWare I2C adapter driver (master). * * Copyright (C) 2016 Synopsys Inc. - * - * ---------------------------------------------------------------------------- - * - * 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. - * ---------------------------------------------------------------------------- - * */ #include <linux/delay.h> #include <linux/err.h> @@ -51,53 +38,18 @@ static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev) */ static int i2c_dw_init_slave(struct dw_i2c_dev *dev) { - u32 reg, comp_param1; int ret; ret = i2c_dw_acquire_lock(dev); if (ret) return ret; - reg = dw_readl(dev, DW_IC_COMP_TYPE); - if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) { - /* Configure register endianness access. */ - dev->flags |= ACCESS_SWAP; - } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) { - /* Configure register access mode 16bit. */ - dev->flags |= ACCESS_16BIT; - } else if (reg != DW_IC_COMP_TYPE_VALUE) { - dev_err(dev->dev, - "Unknown Synopsys component type: 0x%08x\n", reg); - i2c_dw_release_lock(dev); - return -ENODEV; - } - - comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1); - /* Disable the adapter. */ __i2c_dw_disable(dev); - /* Configure SDA Hold Time if required. */ - reg = dw_readl(dev, DW_IC_COMP_VERSION); - if (reg >= DW_IC_SDA_HOLD_MIN_VERS) { - if (!dev->sda_hold_time) { - /* Keep previous hold time setting if no one set it. */ - dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD); - } - /* - * Workaround for avoiding TX arbitration lost in case I2C - * slave pulls SDA down "too quickly" after falling egde of - * SCL by enabling non-zero SDA RX hold. Specification says it - * extends incoming SDA low to high transition while SCL is - * high but it apprears to help also above issue. - */ - if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK)) - dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT; + /* Write SDA hold time if supported */ + if (dev->sda_hold_time) dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); - } else { - dev_warn(dev->dev, - "Hardware too old to adjust SDA hold time.\n"); - } i2c_dw_configure_fifo_slave(dev); i2c_dw_release_lock(dev); @@ -299,6 +251,14 @@ int i2c_dw_probe_slave(struct dw_i2c_dev *dev) dev->disable = i2c_dw_disable; dev->disable_int = i2c_dw_disable_int; + ret = i2c_dw_set_reg_access(dev); + if (ret) + return ret; + + ret = i2c_dw_set_sda_hold(dev); + if (ret) + return ret; + ret = dev->init(dev); if (ret) return ret; |