![Barry Song](/assets/img/avatar_default.png)
This code is repeated in probe: i2c_dev->adapter.algo = &tegra_i2c_algo; Cc: Donglin Peng <pengdonglin137@163.com> Signed-off-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
975 lines
27 KiB
C
975 lines
27 KiB
C
/*
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* drivers/i2c/busses/i2c-tegra.c
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*
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* Copyright (C) 2010 Google, Inc.
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* Author: Colin Cross <ccross@android.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/io.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/of_device.h>
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#include <linux/module.h>
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#include <linux/reset.h>
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#include <asm/unaligned.h>
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#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
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#define BYTES_PER_FIFO_WORD 4
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#define I2C_CNFG 0x000
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#define I2C_CNFG_DEBOUNCE_CNT_SHIFT 12
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#define I2C_CNFG_PACKET_MODE_EN (1<<10)
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#define I2C_CNFG_NEW_MASTER_FSM (1<<11)
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#define I2C_STATUS 0x01C
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#define I2C_SL_CNFG 0x020
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#define I2C_SL_CNFG_NACK (1<<1)
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#define I2C_SL_CNFG_NEWSL (1<<2)
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#define I2C_SL_ADDR1 0x02c
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#define I2C_SL_ADDR2 0x030
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#define I2C_TX_FIFO 0x050
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#define I2C_RX_FIFO 0x054
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#define I2C_PACKET_TRANSFER_STATUS 0x058
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#define I2C_FIFO_CONTROL 0x05c
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#define I2C_FIFO_CONTROL_TX_FLUSH (1<<1)
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#define I2C_FIFO_CONTROL_RX_FLUSH (1<<0)
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#define I2C_FIFO_CONTROL_TX_TRIG_SHIFT 5
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#define I2C_FIFO_CONTROL_RX_TRIG_SHIFT 2
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#define I2C_FIFO_STATUS 0x060
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#define I2C_FIFO_STATUS_TX_MASK 0xF0
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#define I2C_FIFO_STATUS_TX_SHIFT 4
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#define I2C_FIFO_STATUS_RX_MASK 0x0F
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#define I2C_FIFO_STATUS_RX_SHIFT 0
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#define I2C_INT_MASK 0x064
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#define I2C_INT_STATUS 0x068
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#define I2C_INT_PACKET_XFER_COMPLETE (1<<7)
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#define I2C_INT_ALL_PACKETS_XFER_COMPLETE (1<<6)
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#define I2C_INT_TX_FIFO_OVERFLOW (1<<5)
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#define I2C_INT_RX_FIFO_UNDERFLOW (1<<4)
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#define I2C_INT_NO_ACK (1<<3)
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#define I2C_INT_ARBITRATION_LOST (1<<2)
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#define I2C_INT_TX_FIFO_DATA_REQ (1<<1)
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#define I2C_INT_RX_FIFO_DATA_REQ (1<<0)
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#define I2C_CLK_DIVISOR 0x06c
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#define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT 16
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#define I2C_CLK_MULTIPLIER_STD_FAST_MODE 8
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#define DVC_CTRL_REG1 0x000
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#define DVC_CTRL_REG1_INTR_EN (1<<10)
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#define DVC_CTRL_REG2 0x004
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#define DVC_CTRL_REG3 0x008
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#define DVC_CTRL_REG3_SW_PROG (1<<26)
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#define DVC_CTRL_REG3_I2C_DONE_INTR_EN (1<<30)
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#define DVC_STATUS 0x00c
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#define DVC_STATUS_I2C_DONE_INTR (1<<30)
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#define I2C_ERR_NONE 0x00
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#define I2C_ERR_NO_ACK 0x01
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#define I2C_ERR_ARBITRATION_LOST 0x02
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#define I2C_ERR_UNKNOWN_INTERRUPT 0x04
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#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
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#define PACKET_HEADER0_PACKET_ID_SHIFT 16
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#define PACKET_HEADER0_CONT_ID_SHIFT 12
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#define PACKET_HEADER0_PROTOCOL_I2C (1<<4)
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#define I2C_HEADER_HIGHSPEED_MODE (1<<22)
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#define I2C_HEADER_CONT_ON_NAK (1<<21)
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#define I2C_HEADER_SEND_START_BYTE (1<<20)
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#define I2C_HEADER_READ (1<<19)
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#define I2C_HEADER_10BIT_ADDR (1<<18)
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#define I2C_HEADER_IE_ENABLE (1<<17)
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#define I2C_HEADER_REPEAT_START (1<<16)
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#define I2C_HEADER_CONTINUE_XFER (1<<15)
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#define I2C_HEADER_MASTER_ADDR_SHIFT 12
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#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
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#define I2C_CONFIG_LOAD 0x08C
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#define I2C_MSTR_CONFIG_LOAD (1 << 0)
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#define I2C_SLV_CONFIG_LOAD (1 << 1)
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#define I2C_TIMEOUT_CONFIG_LOAD (1 << 2)
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/*
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* msg_end_type: The bus control which need to be send at end of transfer.
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* @MSG_END_STOP: Send stop pulse at end of transfer.
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* @MSG_END_REPEAT_START: Send repeat start at end of transfer.
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* @MSG_END_CONTINUE: The following on message is coming and so do not send
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* stop or repeat start.
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*/
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enum msg_end_type {
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MSG_END_STOP,
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MSG_END_REPEAT_START,
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MSG_END_CONTINUE,
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};
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/**
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* struct tegra_i2c_hw_feature : Different HW support on Tegra
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* @has_continue_xfer_support: Continue transfer supports.
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* @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
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* complete interrupt per packet basis.
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* @has_single_clk_source: The i2c controller has single clock source. Tegra30
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* and earlier Socs has two clock sources i.e. div-clk and
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* fast-clk.
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* @has_config_load_reg: Has the config load register to load the new
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* configuration.
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* @clk_divisor_hs_mode: Clock divisor in HS mode.
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* @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
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* applicable if there is no fast clock source i.e. single clock
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* source.
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*/
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struct tegra_i2c_hw_feature {
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bool has_continue_xfer_support;
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bool has_per_pkt_xfer_complete_irq;
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bool has_single_clk_source;
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bool has_config_load_reg;
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int clk_divisor_hs_mode;
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int clk_divisor_std_fast_mode;
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u16 clk_divisor_fast_plus_mode;
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};
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/**
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* struct tegra_i2c_dev - per device i2c context
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* @dev: device reference for power management
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* @hw: Tegra i2c hw feature.
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* @adapter: core i2c layer adapter information
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* @div_clk: clock reference for div clock of i2c controller.
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* @fast_clk: clock reference for fast clock of i2c controller.
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* @base: ioremapped registers cookie
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* @cont_id: i2c controller id, used for for packet header
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* @irq: irq number of transfer complete interrupt
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* @is_dvc: identifies the DVC i2c controller, has a different register layout
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* @msg_complete: transfer completion notifier
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* @msg_err: error code for completed message
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* @msg_buf: pointer to current message data
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* @msg_buf_remaining: size of unsent data in the message buffer
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* @msg_read: identifies read transfers
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* @bus_clk_rate: current i2c bus clock rate
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* @is_suspended: prevents i2c controller accesses after suspend is called
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*/
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struct tegra_i2c_dev {
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struct device *dev;
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const struct tegra_i2c_hw_feature *hw;
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struct i2c_adapter adapter;
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struct clk *div_clk;
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struct clk *fast_clk;
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struct reset_control *rst;
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void __iomem *base;
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int cont_id;
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int irq;
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bool irq_disabled;
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int is_dvc;
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struct completion msg_complete;
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int msg_err;
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u8 *msg_buf;
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size_t msg_buf_remaining;
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int msg_read;
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u32 bus_clk_rate;
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u16 clk_divisor_non_hs_mode;
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bool is_suspended;
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};
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static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
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{
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writel(val, i2c_dev->base + reg);
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}
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static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
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{
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return readl(i2c_dev->base + reg);
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}
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/*
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* i2c_writel and i2c_readl will offset the register if necessary to talk
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* to the I2C block inside the DVC block
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*/
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static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
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unsigned long reg)
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{
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if (i2c_dev->is_dvc)
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reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
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return reg;
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}
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static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
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unsigned long reg)
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{
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writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
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/* Read back register to make sure that register writes completed */
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if (reg != I2C_TX_FIFO)
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readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
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}
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static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
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{
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return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
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}
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static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
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unsigned long reg, int len)
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{
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writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
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}
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static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
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unsigned long reg, int len)
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{
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readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
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}
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static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
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{
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u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
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int_mask &= ~mask;
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i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
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}
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static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
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{
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u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
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int_mask |= mask;
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i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
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}
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static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
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{
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unsigned long timeout = jiffies + HZ;
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u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
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val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
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i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
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while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
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(I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
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if (time_after(jiffies, timeout)) {
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dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
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return -ETIMEDOUT;
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}
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msleep(1);
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}
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return 0;
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}
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static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
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{
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u32 val;
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int rx_fifo_avail;
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u8 *buf = i2c_dev->msg_buf;
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size_t buf_remaining = i2c_dev->msg_buf_remaining;
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int words_to_transfer;
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val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
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rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
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I2C_FIFO_STATUS_RX_SHIFT;
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/* Rounds down to not include partial word at the end of buf */
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words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
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if (words_to_transfer > rx_fifo_avail)
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words_to_transfer = rx_fifo_avail;
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i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
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buf += words_to_transfer * BYTES_PER_FIFO_WORD;
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buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
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rx_fifo_avail -= words_to_transfer;
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/*
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* If there is a partial word at the end of buf, handle it manually to
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* prevent overwriting past the end of buf
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*/
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if (rx_fifo_avail > 0 && buf_remaining > 0) {
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BUG_ON(buf_remaining > 3);
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val = i2c_readl(i2c_dev, I2C_RX_FIFO);
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val = cpu_to_le32(val);
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memcpy(buf, &val, buf_remaining);
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buf_remaining = 0;
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rx_fifo_avail--;
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}
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BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
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i2c_dev->msg_buf_remaining = buf_remaining;
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i2c_dev->msg_buf = buf;
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return 0;
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}
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static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
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{
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u32 val;
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int tx_fifo_avail;
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u8 *buf = i2c_dev->msg_buf;
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size_t buf_remaining = i2c_dev->msg_buf_remaining;
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int words_to_transfer;
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val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
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tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
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I2C_FIFO_STATUS_TX_SHIFT;
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/* Rounds down to not include partial word at the end of buf */
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words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
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/* It's very common to have < 4 bytes, so optimize that case. */
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if (words_to_transfer) {
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if (words_to_transfer > tx_fifo_avail)
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words_to_transfer = tx_fifo_avail;
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/*
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* Update state before writing to FIFO. If this casues us
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* to finish writing all bytes (AKA buf_remaining goes to 0) we
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* have a potential for an interrupt (PACKET_XFER_COMPLETE is
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* not maskable). We need to make sure that the isr sees
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* buf_remaining as 0 and doesn't call us back re-entrantly.
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*/
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buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
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tx_fifo_avail -= words_to_transfer;
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i2c_dev->msg_buf_remaining = buf_remaining;
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i2c_dev->msg_buf = buf +
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words_to_transfer * BYTES_PER_FIFO_WORD;
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barrier();
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i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
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buf += words_to_transfer * BYTES_PER_FIFO_WORD;
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}
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/*
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* If there is a partial word at the end of buf, handle it manually to
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* prevent reading past the end of buf, which could cross a page
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* boundary and fault.
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*/
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if (tx_fifo_avail > 0 && buf_remaining > 0) {
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BUG_ON(buf_remaining > 3);
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memcpy(&val, buf, buf_remaining);
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val = le32_to_cpu(val);
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/* Again update before writing to FIFO to make sure isr sees. */
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i2c_dev->msg_buf_remaining = 0;
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i2c_dev->msg_buf = NULL;
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barrier();
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i2c_writel(i2c_dev, val, I2C_TX_FIFO);
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}
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return 0;
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}
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/*
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* One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
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* block. This block is identical to the rest of the I2C blocks, except that
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* it only supports master mode, it has registers moved around, and it needs
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* some extra init to get it into I2C mode. The register moves are handled
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* by i2c_readl and i2c_writel
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*/
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static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
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{
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u32 val = 0;
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val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
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val |= DVC_CTRL_REG3_SW_PROG;
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val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
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dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
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val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
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val |= DVC_CTRL_REG1_INTR_EN;
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dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
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}
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static inline int tegra_i2c_clock_enable(struct tegra_i2c_dev *i2c_dev)
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{
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int ret;
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if (!i2c_dev->hw->has_single_clk_source) {
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ret = clk_enable(i2c_dev->fast_clk);
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if (ret < 0) {
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dev_err(i2c_dev->dev,
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"Enabling fast clk failed, err %d\n", ret);
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return ret;
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}
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}
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ret = clk_enable(i2c_dev->div_clk);
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if (ret < 0) {
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dev_err(i2c_dev->dev,
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"Enabling div clk failed, err %d\n", ret);
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clk_disable(i2c_dev->fast_clk);
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}
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return ret;
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}
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static inline void tegra_i2c_clock_disable(struct tegra_i2c_dev *i2c_dev)
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{
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clk_disable(i2c_dev->div_clk);
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if (!i2c_dev->hw->has_single_clk_source)
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clk_disable(i2c_dev->fast_clk);
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}
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|
|
static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
|
|
{
|
|
u32 val;
|
|
int err = 0;
|
|
u32 clk_divisor;
|
|
unsigned long timeout = jiffies + HZ;
|
|
|
|
err = tegra_i2c_clock_enable(i2c_dev);
|
|
if (err < 0) {
|
|
dev_err(i2c_dev->dev, "Clock enable failed %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
reset_control_assert(i2c_dev->rst);
|
|
udelay(2);
|
|
reset_control_deassert(i2c_dev->rst);
|
|
|
|
if (i2c_dev->is_dvc)
|
|
tegra_dvc_init(i2c_dev);
|
|
|
|
val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
|
|
(0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
|
|
i2c_writel(i2c_dev, val, I2C_CNFG);
|
|
i2c_writel(i2c_dev, 0, I2C_INT_MASK);
|
|
|
|
/* Make sure clock divisor programmed correctly */
|
|
clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
|
|
clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
|
|
I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
|
|
i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
|
|
|
|
if (!i2c_dev->is_dvc) {
|
|
u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
|
|
sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
|
|
i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
|
|
i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
|
|
i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
|
|
|
|
}
|
|
|
|
val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
|
|
0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
|
|
i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
|
|
|
|
if (tegra_i2c_flush_fifos(i2c_dev))
|
|
err = -ETIMEDOUT;
|
|
|
|
if (i2c_dev->hw->has_config_load_reg) {
|
|
i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
|
|
while (i2c_readl(i2c_dev, I2C_CONFIG_LOAD) != 0) {
|
|
if (time_after(jiffies, timeout)) {
|
|
dev_warn(i2c_dev->dev,
|
|
"timeout waiting for config load\n");
|
|
return -ETIMEDOUT;
|
|
}
|
|
msleep(1);
|
|
}
|
|
}
|
|
|
|
tegra_i2c_clock_disable(i2c_dev);
|
|
|
|
if (i2c_dev->irq_disabled) {
|
|
i2c_dev->irq_disabled = 0;
|
|
enable_irq(i2c_dev->irq);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
|
|
{
|
|
u32 status;
|
|
const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
|
|
struct tegra_i2c_dev *i2c_dev = dev_id;
|
|
|
|
status = i2c_readl(i2c_dev, I2C_INT_STATUS);
|
|
|
|
if (status == 0) {
|
|
dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
|
|
i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
|
|
i2c_readl(i2c_dev, I2C_STATUS),
|
|
i2c_readl(i2c_dev, I2C_CNFG));
|
|
i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
|
|
|
|
if (!i2c_dev->irq_disabled) {
|
|
disable_irq_nosync(i2c_dev->irq);
|
|
i2c_dev->irq_disabled = 1;
|
|
}
|
|
goto err;
|
|
}
|
|
|
|
if (unlikely(status & status_err)) {
|
|
if (status & I2C_INT_NO_ACK)
|
|
i2c_dev->msg_err |= I2C_ERR_NO_ACK;
|
|
if (status & I2C_INT_ARBITRATION_LOST)
|
|
i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
|
|
goto err;
|
|
}
|
|
|
|
if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
|
|
if (i2c_dev->msg_buf_remaining)
|
|
tegra_i2c_empty_rx_fifo(i2c_dev);
|
|
else
|
|
BUG();
|
|
}
|
|
|
|
if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
|
|
if (i2c_dev->msg_buf_remaining)
|
|
tegra_i2c_fill_tx_fifo(i2c_dev);
|
|
else
|
|
tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
|
|
}
|
|
|
|
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
|
|
if (i2c_dev->is_dvc)
|
|
dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
|
|
|
|
if (status & I2C_INT_PACKET_XFER_COMPLETE) {
|
|
BUG_ON(i2c_dev->msg_buf_remaining);
|
|
complete(&i2c_dev->msg_complete);
|
|
}
|
|
return IRQ_HANDLED;
|
|
err:
|
|
/* An error occurred, mask all interrupts */
|
|
tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
|
|
I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
|
|
I2C_INT_RX_FIFO_DATA_REQ);
|
|
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
|
|
if (i2c_dev->is_dvc)
|
|
dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
|
|
|
|
complete(&i2c_dev->msg_complete);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
|
|
struct i2c_msg *msg, enum msg_end_type end_state)
|
|
{
|
|
u32 packet_header;
|
|
u32 int_mask;
|
|
unsigned long time_left;
|
|
|
|
tegra_i2c_flush_fifos(i2c_dev);
|
|
|
|
if (msg->len == 0)
|
|
return -EINVAL;
|
|
|
|
i2c_dev->msg_buf = msg->buf;
|
|
i2c_dev->msg_buf_remaining = msg->len;
|
|
i2c_dev->msg_err = I2C_ERR_NONE;
|
|
i2c_dev->msg_read = (msg->flags & I2C_M_RD);
|
|
reinit_completion(&i2c_dev->msg_complete);
|
|
|
|
packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
|
|
PACKET_HEADER0_PROTOCOL_I2C |
|
|
(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
|
|
(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
|
|
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
|
|
|
|
packet_header = msg->len - 1;
|
|
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
|
|
|
|
packet_header = I2C_HEADER_IE_ENABLE;
|
|
if (end_state == MSG_END_CONTINUE)
|
|
packet_header |= I2C_HEADER_CONTINUE_XFER;
|
|
else if (end_state == MSG_END_REPEAT_START)
|
|
packet_header |= I2C_HEADER_REPEAT_START;
|
|
if (msg->flags & I2C_M_TEN) {
|
|
packet_header |= msg->addr;
|
|
packet_header |= I2C_HEADER_10BIT_ADDR;
|
|
} else {
|
|
packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
|
|
}
|
|
if (msg->flags & I2C_M_IGNORE_NAK)
|
|
packet_header |= I2C_HEADER_CONT_ON_NAK;
|
|
if (msg->flags & I2C_M_RD)
|
|
packet_header |= I2C_HEADER_READ;
|
|
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
|
|
|
|
if (!(msg->flags & I2C_M_RD))
|
|
tegra_i2c_fill_tx_fifo(i2c_dev);
|
|
|
|
int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
|
|
if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
|
|
int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
|
|
if (msg->flags & I2C_M_RD)
|
|
int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
|
|
else if (i2c_dev->msg_buf_remaining)
|
|
int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
|
|
tegra_i2c_unmask_irq(i2c_dev, int_mask);
|
|
dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
|
|
i2c_readl(i2c_dev, I2C_INT_MASK));
|
|
|
|
time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
|
|
TEGRA_I2C_TIMEOUT);
|
|
tegra_i2c_mask_irq(i2c_dev, int_mask);
|
|
|
|
if (time_left == 0) {
|
|
dev_err(i2c_dev->dev, "i2c transfer timed out\n");
|
|
|
|
tegra_i2c_init(i2c_dev);
|
|
return -ETIMEDOUT;
|
|
}
|
|
|
|
dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
|
|
time_left, completion_done(&i2c_dev->msg_complete),
|
|
i2c_dev->msg_err);
|
|
|
|
if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
|
|
return 0;
|
|
|
|
/*
|
|
* NACK interrupt is generated before the I2C controller generates the
|
|
* STOP condition on the bus. So wait for 2 clock periods before resetting
|
|
* the controller so that STOP condition has been delivered properly.
|
|
*/
|
|
if (i2c_dev->msg_err == I2C_ERR_NO_ACK)
|
|
udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
|
|
|
|
tegra_i2c_init(i2c_dev);
|
|
if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
|
|
if (msg->flags & I2C_M_IGNORE_NAK)
|
|
return 0;
|
|
return -EREMOTEIO;
|
|
}
|
|
|
|
return -EIO;
|
|
}
|
|
|
|
static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
|
|
int num)
|
|
{
|
|
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
|
|
int i;
|
|
int ret = 0;
|
|
|
|
if (i2c_dev->is_suspended)
|
|
return -EBUSY;
|
|
|
|
ret = tegra_i2c_clock_enable(i2c_dev);
|
|
if (ret < 0) {
|
|
dev_err(i2c_dev->dev, "Clock enable failed %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
for (i = 0; i < num; i++) {
|
|
enum msg_end_type end_type = MSG_END_STOP;
|
|
if (i < (num - 1)) {
|
|
if (msgs[i + 1].flags & I2C_M_NOSTART)
|
|
end_type = MSG_END_CONTINUE;
|
|
else
|
|
end_type = MSG_END_REPEAT_START;
|
|
}
|
|
ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
|
|
if (ret)
|
|
break;
|
|
}
|
|
tegra_i2c_clock_disable(i2c_dev);
|
|
return ret ?: i;
|
|
}
|
|
|
|
static u32 tegra_i2c_func(struct i2c_adapter *adap)
|
|
{
|
|
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
|
|
u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
|
|
I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
|
|
|
|
if (i2c_dev->hw->has_continue_xfer_support)
|
|
ret |= I2C_FUNC_NOSTART;
|
|
return ret;
|
|
}
|
|
|
|
static const struct i2c_algorithm tegra_i2c_algo = {
|
|
.master_xfer = tegra_i2c_xfer,
|
|
.functionality = tegra_i2c_func,
|
|
};
|
|
|
|
/* payload size is only 12 bit */
|
|
static struct i2c_adapter_quirks tegra_i2c_quirks = {
|
|
.max_read_len = 4096,
|
|
.max_write_len = 4096,
|
|
};
|
|
|
|
static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
|
|
.has_continue_xfer_support = false,
|
|
.has_per_pkt_xfer_complete_irq = false,
|
|
.has_single_clk_source = false,
|
|
.clk_divisor_hs_mode = 3,
|
|
.clk_divisor_std_fast_mode = 0,
|
|
.clk_divisor_fast_plus_mode = 0,
|
|
.has_config_load_reg = false,
|
|
};
|
|
|
|
static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
|
|
.has_continue_xfer_support = true,
|
|
.has_per_pkt_xfer_complete_irq = false,
|
|
.has_single_clk_source = false,
|
|
.clk_divisor_hs_mode = 3,
|
|
.clk_divisor_std_fast_mode = 0,
|
|
.clk_divisor_fast_plus_mode = 0,
|
|
.has_config_load_reg = false,
|
|
};
|
|
|
|
static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
|
|
.has_continue_xfer_support = true,
|
|
.has_per_pkt_xfer_complete_irq = true,
|
|
.has_single_clk_source = true,
|
|
.clk_divisor_hs_mode = 1,
|
|
.clk_divisor_std_fast_mode = 0x19,
|
|
.clk_divisor_fast_plus_mode = 0x10,
|
|
.has_config_load_reg = false,
|
|
};
|
|
|
|
static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
|
|
.has_continue_xfer_support = true,
|
|
.has_per_pkt_xfer_complete_irq = true,
|
|
.has_single_clk_source = true,
|
|
.clk_divisor_hs_mode = 1,
|
|
.clk_divisor_std_fast_mode = 0x19,
|
|
.clk_divisor_fast_plus_mode = 0x10,
|
|
.has_config_load_reg = true,
|
|
};
|
|
|
|
/* Match table for of_platform binding */
|
|
static const struct of_device_id tegra_i2c_of_match[] = {
|
|
{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
|
|
{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
|
|
{ .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
|
|
{ .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
|
|
{ .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
|
|
|
|
static int tegra_i2c_probe(struct platform_device *pdev)
|
|
{
|
|
struct tegra_i2c_dev *i2c_dev;
|
|
struct resource *res;
|
|
struct clk *div_clk;
|
|
struct clk *fast_clk;
|
|
void __iomem *base;
|
|
int irq;
|
|
int ret = 0;
|
|
int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(base))
|
|
return PTR_ERR(base);
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
|
|
if (!res) {
|
|
dev_err(&pdev->dev, "no irq resource\n");
|
|
return -EINVAL;
|
|
}
|
|
irq = res->start;
|
|
|
|
div_clk = devm_clk_get(&pdev->dev, "div-clk");
|
|
if (IS_ERR(div_clk)) {
|
|
dev_err(&pdev->dev, "missing controller clock");
|
|
return PTR_ERR(div_clk);
|
|
}
|
|
|
|
i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
|
|
if (!i2c_dev)
|
|
return -ENOMEM;
|
|
|
|
i2c_dev->base = base;
|
|
i2c_dev->div_clk = div_clk;
|
|
i2c_dev->adapter.algo = &tegra_i2c_algo;
|
|
i2c_dev->adapter.quirks = &tegra_i2c_quirks;
|
|
i2c_dev->irq = irq;
|
|
i2c_dev->cont_id = pdev->id;
|
|
i2c_dev->dev = &pdev->dev;
|
|
|
|
i2c_dev->rst = devm_reset_control_get(&pdev->dev, "i2c");
|
|
if (IS_ERR(i2c_dev->rst)) {
|
|
dev_err(&pdev->dev, "missing controller reset");
|
|
return PTR_ERR(i2c_dev->rst);
|
|
}
|
|
|
|
ret = of_property_read_u32(i2c_dev->dev->of_node, "clock-frequency",
|
|
&i2c_dev->bus_clk_rate);
|
|
if (ret)
|
|
i2c_dev->bus_clk_rate = 100000; /* default clock rate */
|
|
|
|
i2c_dev->hw = &tegra20_i2c_hw;
|
|
|
|
if (pdev->dev.of_node) {
|
|
const struct of_device_id *match;
|
|
match = of_match_device(tegra_i2c_of_match, &pdev->dev);
|
|
i2c_dev->hw = match->data;
|
|
i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
|
|
"nvidia,tegra20-i2c-dvc");
|
|
} else if (pdev->id == 3) {
|
|
i2c_dev->is_dvc = 1;
|
|
}
|
|
init_completion(&i2c_dev->msg_complete);
|
|
|
|
if (!i2c_dev->hw->has_single_clk_source) {
|
|
fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
|
|
if (IS_ERR(fast_clk)) {
|
|
dev_err(&pdev->dev, "missing fast clock");
|
|
return PTR_ERR(fast_clk);
|
|
}
|
|
i2c_dev->fast_clk = fast_clk;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, i2c_dev);
|
|
|
|
if (!i2c_dev->hw->has_single_clk_source) {
|
|
ret = clk_prepare(i2c_dev->fast_clk);
|
|
if (ret < 0) {
|
|
dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
i2c_dev->clk_divisor_non_hs_mode =
|
|
i2c_dev->hw->clk_divisor_std_fast_mode;
|
|
if (i2c_dev->hw->clk_divisor_fast_plus_mode &&
|
|
(i2c_dev->bus_clk_rate == 1000000))
|
|
i2c_dev->clk_divisor_non_hs_mode =
|
|
i2c_dev->hw->clk_divisor_fast_plus_mode;
|
|
|
|
clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
|
|
ret = clk_set_rate(i2c_dev->div_clk,
|
|
i2c_dev->bus_clk_rate * clk_multiplier);
|
|
if (ret) {
|
|
dev_err(i2c_dev->dev, "Clock rate change failed %d\n", ret);
|
|
goto unprepare_fast_clk;
|
|
}
|
|
|
|
ret = clk_prepare(i2c_dev->div_clk);
|
|
if (ret < 0) {
|
|
dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
|
|
goto unprepare_fast_clk;
|
|
}
|
|
|
|
ret = tegra_i2c_init(i2c_dev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Failed to initialize i2c controller");
|
|
goto unprepare_div_clk;
|
|
}
|
|
|
|
ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
|
|
tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
|
|
goto unprepare_div_clk;
|
|
}
|
|
|
|
i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
|
|
i2c_dev->adapter.owner = THIS_MODULE;
|
|
i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
|
|
strlcpy(i2c_dev->adapter.name, "Tegra I2C adapter",
|
|
sizeof(i2c_dev->adapter.name));
|
|
i2c_dev->adapter.dev.parent = &pdev->dev;
|
|
i2c_dev->adapter.nr = pdev->id;
|
|
i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
|
|
|
|
ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Failed to add I2C adapter\n");
|
|
goto unprepare_div_clk;
|
|
}
|
|
|
|
return 0;
|
|
|
|
unprepare_div_clk:
|
|
clk_unprepare(i2c_dev->div_clk);
|
|
|
|
unprepare_fast_clk:
|
|
if (!i2c_dev->hw->has_single_clk_source)
|
|
clk_unprepare(i2c_dev->fast_clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int tegra_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
|
|
i2c_del_adapter(&i2c_dev->adapter);
|
|
|
|
clk_unprepare(i2c_dev->div_clk);
|
|
if (!i2c_dev->hw->has_single_clk_source)
|
|
clk_unprepare(i2c_dev->fast_clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int tegra_i2c_suspend(struct device *dev)
|
|
{
|
|
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
|
|
|
|
i2c_lock_adapter(&i2c_dev->adapter);
|
|
i2c_dev->is_suspended = true;
|
|
i2c_unlock_adapter(&i2c_dev->adapter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tegra_i2c_resume(struct device *dev)
|
|
{
|
|
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
|
|
int ret;
|
|
|
|
i2c_lock_adapter(&i2c_dev->adapter);
|
|
|
|
ret = tegra_i2c_init(i2c_dev);
|
|
|
|
if (ret) {
|
|
i2c_unlock_adapter(&i2c_dev->adapter);
|
|
return ret;
|
|
}
|
|
|
|
i2c_dev->is_suspended = false;
|
|
|
|
i2c_unlock_adapter(&i2c_dev->adapter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static SIMPLE_DEV_PM_OPS(tegra_i2c_pm, tegra_i2c_suspend, tegra_i2c_resume);
|
|
#define TEGRA_I2C_PM (&tegra_i2c_pm)
|
|
#else
|
|
#define TEGRA_I2C_PM NULL
|
|
#endif
|
|
|
|
static struct platform_driver tegra_i2c_driver = {
|
|
.probe = tegra_i2c_probe,
|
|
.remove = tegra_i2c_remove,
|
|
.driver = {
|
|
.name = "tegra-i2c",
|
|
.of_match_table = tegra_i2c_of_match,
|
|
.pm = TEGRA_I2C_PM,
|
|
},
|
|
};
|
|
|
|
static int __init tegra_i2c_init_driver(void)
|
|
{
|
|
return platform_driver_register(&tegra_i2c_driver);
|
|
}
|
|
|
|
static void __exit tegra_i2c_exit_driver(void)
|
|
{
|
|
platform_driver_unregister(&tegra_i2c_driver);
|
|
}
|
|
|
|
subsys_initcall(tegra_i2c_init_driver);
|
|
module_exit(tegra_i2c_exit_driver);
|
|
|
|
MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
|
|
MODULE_AUTHOR("Colin Cross");
|
|
MODULE_LICENSE("GPL v2");
|