diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-jz4780.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-jz4780.c | 805 |
1 files changed, 805 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-jz4780.c b/drivers/i2c/busses/i2c-jz4780.c new file mode 100644 index 000000000..4dd800c0d --- /dev/null +++ b/drivers/i2c/busses/i2c-jz4780.c @@ -0,0 +1,805 @@ +/* + * Ingenic JZ4780 I2C bus driver + * + * Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc. + * Copyright (C) 2015 Imagination Technologies + * + * 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/bitops.h> +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/time.h> + +#define JZ4780_I2C_CTRL 0x00 +#define JZ4780_I2C_TAR 0x04 +#define JZ4780_I2C_SAR 0x08 +#define JZ4780_I2C_DC 0x10 +#define JZ4780_I2C_SHCNT 0x14 +#define JZ4780_I2C_SLCNT 0x18 +#define JZ4780_I2C_FHCNT 0x1C +#define JZ4780_I2C_FLCNT 0x20 +#define JZ4780_I2C_INTST 0x2C +#define JZ4780_I2C_INTM 0x30 +#define JZ4780_I2C_RXTL 0x38 +#define JZ4780_I2C_TXTL 0x3C +#define JZ4780_I2C_CINTR 0x40 +#define JZ4780_I2C_CRXUF 0x44 +#define JZ4780_I2C_CRXOF 0x48 +#define JZ4780_I2C_CTXOF 0x4C +#define JZ4780_I2C_CRXREQ 0x50 +#define JZ4780_I2C_CTXABRT 0x54 +#define JZ4780_I2C_CRXDONE 0x58 +#define JZ4780_I2C_CACT 0x5C +#define JZ4780_I2C_CSTP 0x60 +#define JZ4780_I2C_CSTT 0x64 +#define JZ4780_I2C_CGC 0x68 +#define JZ4780_I2C_ENB 0x6C +#define JZ4780_I2C_STA 0x70 +#define JZ4780_I2C_TXABRT 0x80 +#define JZ4780_I2C_DMACR 0x88 +#define JZ4780_I2C_DMATDLR 0x8C +#define JZ4780_I2C_DMARDLR 0x90 +#define JZ4780_I2C_SDASU 0x94 +#define JZ4780_I2C_ACKGC 0x98 +#define JZ4780_I2C_ENSTA 0x9C +#define JZ4780_I2C_SDAHD 0xD0 + +#define JZ4780_I2C_CTRL_STPHLD BIT(7) +#define JZ4780_I2C_CTRL_SLVDIS BIT(6) +#define JZ4780_I2C_CTRL_REST BIT(5) +#define JZ4780_I2C_CTRL_MATP BIT(4) +#define JZ4780_I2C_CTRL_SATP BIT(3) +#define JZ4780_I2C_CTRL_SPDF BIT(2) +#define JZ4780_I2C_CTRL_SPDS BIT(1) +#define JZ4780_I2C_CTRL_MD BIT(0) + +#define JZ4780_I2C_STA_SLVACT BIT(6) +#define JZ4780_I2C_STA_MSTACT BIT(5) +#define JZ4780_I2C_STA_RFF BIT(4) +#define JZ4780_I2C_STA_RFNE BIT(3) +#define JZ4780_I2C_STA_TFE BIT(2) +#define JZ4780_I2C_STA_TFNF BIT(1) +#define JZ4780_I2C_STA_ACT BIT(0) + +#define JZ4780_I2C_INTST_IGC BIT(11) +#define JZ4780_I2C_INTST_ISTT BIT(10) +#define JZ4780_I2C_INTST_ISTP BIT(9) +#define JZ4780_I2C_INTST_IACT BIT(8) +#define JZ4780_I2C_INTST_RXDN BIT(7) +#define JZ4780_I2C_INTST_TXABT BIT(6) +#define JZ4780_I2C_INTST_RDREQ BIT(5) +#define JZ4780_I2C_INTST_TXEMP BIT(4) +#define JZ4780_I2C_INTST_TXOF BIT(3) +#define JZ4780_I2C_INTST_RXFL BIT(2) +#define JZ4780_I2C_INTST_RXOF BIT(1) +#define JZ4780_I2C_INTST_RXUF BIT(0) + +#define JZ4780_I2C_INTM_MIGC BIT(11) +#define JZ4780_I2C_INTM_MISTT BIT(10) +#define JZ4780_I2C_INTM_MISTP BIT(9) +#define JZ4780_I2C_INTM_MIACT BIT(8) +#define JZ4780_I2C_INTM_MRXDN BIT(7) +#define JZ4780_I2C_INTM_MTXABT BIT(6) +#define JZ4780_I2C_INTM_MRDREQ BIT(5) +#define JZ4780_I2C_INTM_MTXEMP BIT(4) +#define JZ4780_I2C_INTM_MTXOF BIT(3) +#define JZ4780_I2C_INTM_MRXFL BIT(2) +#define JZ4780_I2C_INTM_MRXOF BIT(1) +#define JZ4780_I2C_INTM_MRXUF BIT(0) + +#define JZ4780_I2C_DC_READ BIT(8) + +#define JZ4780_I2C_SDAHD_HDENB BIT(8) + +#define JZ4780_I2C_ENB_I2C BIT(0) + +#define JZ4780_I2CSHCNT_ADJUST(n) (((n) - 8) < 6 ? 6 : ((n) - 8)) +#define JZ4780_I2CSLCNT_ADJUST(n) (((n) - 1) < 8 ? 8 : ((n) - 1)) +#define JZ4780_I2CFHCNT_ADJUST(n) (((n) - 8) < 6 ? 6 : ((n) - 8)) +#define JZ4780_I2CFLCNT_ADJUST(n) (((n) - 1) < 8 ? 8 : ((n) - 1)) + +#define JZ4780_I2C_FIFO_LEN 16 +#define TX_LEVEL 3 +#define RX_LEVEL (JZ4780_I2C_FIFO_LEN - TX_LEVEL - 1) + +#define JZ4780_I2C_TIMEOUT 300 + +#define BUFSIZE 200 + +struct jz4780_i2c { + void __iomem *iomem; + int irq; + struct clk *clk; + struct i2c_adapter adap; + + /* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */ + spinlock_t lock; + + /* beginning of lock scope */ + unsigned char *rbuf; + int rd_total_len; + int rd_data_xfered; + int rd_cmd_xfered; + + unsigned char *wbuf; + int wt_len; + + int is_write; + int stop_hold; + int speed; + + int data_buf[BUFSIZE]; + int cmd_buf[BUFSIZE]; + int cmd; + + /* end of lock scope */ + struct completion trans_waitq; +}; + +static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c, + unsigned long offset) +{ + return readw(i2c->iomem + offset); +} + +static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c, + unsigned long offset, unsigned short val) +{ + writew(val, i2c->iomem + offset); +} + +static int jz4780_i2c_disable(struct jz4780_i2c *i2c) +{ + unsigned short regval; + unsigned long loops = 5; + + jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0); + + do { + regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA); + if (!(regval & JZ4780_I2C_ENB_I2C)) + return 0; + + usleep_range(5000, 15000); + } while (--loops); + + dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval); + return -ETIMEDOUT; +} + +static int jz4780_i2c_enable(struct jz4780_i2c *i2c) +{ + unsigned short regval; + unsigned long loops = 5; + + jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1); + + do { + regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA); + if (regval & JZ4780_I2C_ENB_I2C) + return 0; + + usleep_range(5000, 15000); + } while (--loops); + + dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval); + return -ETIMEDOUT; +} + +static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address) +{ + unsigned short regval; + unsigned long loops = 5; + + do { + regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA); + if ((regval & JZ4780_I2C_STA_TFE) && + !(regval & JZ4780_I2C_STA_MSTACT)) + break; + + usleep_range(5000, 15000); + } while (--loops); + + if (loops) { + jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address); + return 0; + } + + dev_err(&i2c->adap.dev, + "set device to address 0x%02x failed, STA=0x%04x\n", + address, regval); + + return -ENXIO; +} + +static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c) +{ + int dev_clk_khz = clk_get_rate(i2c->clk) / 1000; + int cnt_high = 0; /* HIGH period count of the SCL clock */ + int cnt_low = 0; /* LOW period count of the SCL clock */ + int cnt_period = 0; /* period count of the SCL clock */ + int setup_time = 0; + int hold_time = 0; + unsigned short tmp = 0; + int i2c_clk = i2c->speed; + + if (jz4780_i2c_disable(i2c)) + dev_dbg(&i2c->adap.dev, "i2c not disabled\n"); + + /* + * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk) + * standard mode, min LOW and HIGH period are 4700 ns and 4000 ns + * fast mode, min LOW and HIGH period are 1300 ns and 600 ns + */ + cnt_period = dev_clk_khz / i2c_clk; + + if (i2c_clk <= 100) + cnt_high = (cnt_period * 4000) / (4700 + 4000); + else + cnt_high = (cnt_period * 600) / (1300 + 600); + + cnt_low = cnt_period - cnt_high; + + /* + * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because + * normal read are 2 messages, we cannot disable i2c controller + * between these two messages, this means that we must always set + * JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL + * + */ + if (i2c_clk <= 100) { + tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST + | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT, + JZ4780_I2CSHCNT_ADJUST(cnt_high)); + jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT, + JZ4780_I2CSLCNT_ADJUST(cnt_low)); + } else { + tmp = JZ4780_I2C_CTRL_SPDF | JZ4780_I2C_CTRL_REST + | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT, + JZ4780_I2CFHCNT_ADJUST(cnt_high)); + jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT, + JZ4780_I2CFLCNT_ADJUST(cnt_low)); + } + + /* + * a i2c device must internally provide a hold time at least 300ns + * tHD:DAT + * Standard Mode: min=300ns, max=3450ns + * Fast Mode: min=0ns, max=900ns + * tSU:DAT + * Standard Mode: min=250ns, max=infinite + * Fast Mode: min=100(250ns is recommended), max=infinite + * + * 1i2c_clk = 10^6 / dev_clk_khz + * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns + * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns + * + * The actual hold time is (SDAHD + 1) * (i2c_clk period). + * + * Length of setup time calculated using (SDASU - 1) * (ic_clk_period) + * + */ + if (i2c_clk <= 100) { /* standard mode */ + setup_time = 300; + hold_time = 400; + } else { + setup_time = 450; + hold_time = 450; + } + + hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1; + setup_time = ((setup_time * dev_clk_khz) / 1000000) + 1; + + if (setup_time > 255) + setup_time = 255; + + if (setup_time <= 0) + setup_time = 1; + + jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time); + + if (hold_time > 255) + hold_time = 255; + + if (hold_time >= 0) { + /*i2c hold time enable */ + hold_time |= JZ4780_I2C_SDAHD_HDENB; + jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time); + } else { + /* disable hold time */ + jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0); + } + + return 0; +} + +static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c) +{ + int ret; + unsigned long flags; + unsigned short tmp; + + spin_lock_irqsave(&i2c->lock, flags); + + /* can send stop now if need */ + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL); + tmp &= ~JZ4780_I2C_CTRL_STPHLD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + /* disable all interrupts first */ + jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0); + + /* then clear all interrupts */ + jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT); + jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR); + + /* then disable the controller */ + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL); + tmp &= ~JZ4780_I2C_ENB_I2C; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + udelay(10); + tmp |= JZ4780_I2C_ENB_I2C; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + spin_unlock_irqrestore(&i2c->lock, flags); + + ret = jz4780_i2c_disable(i2c); + if (ret) + dev_err(&i2c->adap.dev, + "unable to disable device during cleanup!\n"); + + if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM) + & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST))) + dev_err(&i2c->adap.dev, + "device has interrupts after a complete cleanup!\n"); + + return ret; +} + +static int jz4780_i2c_prepare(struct jz4780_i2c *i2c) +{ + jz4780_i2c_set_speed(i2c); + return jz4780_i2c_enable(i2c); +} + +static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c, int cmd_count) +{ + int i; + + for (i = 0; i < cmd_count; i++) + jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ); +} + +static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c) +{ + jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0); + complete(&i2c->trans_waitq); +} + +static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id) +{ + unsigned short tmp; + unsigned short intst; + unsigned short intmsk; + struct jz4780_i2c *i2c = dev_id; + unsigned long flags; + + spin_lock_irqsave(&i2c->lock, flags); + intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM); + intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST); + + intst &= intmsk; + + if (intst & JZ4780_I2C_INTST_TXABT) { + jz4780_i2c_trans_done(i2c); + goto done; + } + + if (intst & JZ4780_I2C_INTST_RXOF) { + dev_dbg(&i2c->adap.dev, "received fifo overflow!\n"); + jz4780_i2c_trans_done(i2c); + goto done; + } + + /* + * When reading, always drain RX FIFO before we send more Read + * Commands to avoid fifo overrun + */ + if (i2c->is_write == 0) { + int rd_left; + + while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA) + & JZ4780_I2C_STA_RFNE)) { + *(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC) + & 0xff; + i2c->rd_data_xfered++; + if (i2c->rd_data_xfered == i2c->rd_total_len) { + jz4780_i2c_trans_done(i2c); + goto done; + } + } + + rd_left = i2c->rd_total_len - i2c->rd_data_xfered; + + if (rd_left <= JZ4780_I2C_FIFO_LEN) + jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1); + } + + if (intst & JZ4780_I2C_INTST_TXEMP) { + if (i2c->is_write == 0) { + int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered; + int max_send = (JZ4780_I2C_FIFO_LEN - 1) + - (i2c->rd_cmd_xfered + - i2c->rd_data_xfered); + int cmd_to_send = min(cmd_left, max_send); + + if (i2c->rd_cmd_xfered != 0) + cmd_to_send = min(cmd_to_send, + JZ4780_I2C_FIFO_LEN + - TX_LEVEL - 1); + + if (cmd_to_send) { + jz4780_i2c_send_rcmd(i2c, cmd_to_send); + i2c->rd_cmd_xfered += cmd_to_send; + } + + cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered; + if (cmd_left == 0) { + intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM); + intmsk &= ~JZ4780_I2C_INTM_MTXEMP; + jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk); + + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL); + tmp &= ~JZ4780_I2C_CTRL_STPHLD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + } + } else { + unsigned short data; + unsigned short i2c_sta; + + i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA); + + while ((i2c_sta & JZ4780_I2C_STA_TFNF) && + (i2c->wt_len > 0)) { + i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA); + data = *i2c->wbuf; + data &= ~JZ4780_I2C_DC_READ; + jz4780_i2c_writew(i2c, JZ4780_I2C_DC, + data); + i2c->wbuf++; + i2c->wt_len--; + } + + if (i2c->wt_len == 0) { + if (!i2c->stop_hold) { + tmp = jz4780_i2c_readw(i2c, + JZ4780_I2C_CTRL); + tmp &= ~JZ4780_I2C_CTRL_STPHLD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, + tmp); + } + + jz4780_i2c_trans_done(i2c); + goto done; + } + } + } + +done: + spin_unlock_irqrestore(&i2c->lock, flags); + return IRQ_HANDLED; +} + +static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src) +{ + dev_dbg(&i2c->adap.dev, "txabrt: 0x%08x, cmd: %d, send: %d, recv: %d\n", + src, i2c->cmd, i2c->cmd_buf[i2c->cmd], i2c->data_buf[i2c->cmd]); +} + +static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c, + unsigned char *buf, int len, int cnt, + int idx) +{ + int ret = 0; + long timeout; + int wait_time = JZ4780_I2C_TIMEOUT * (len + 5); + unsigned short tmp; + unsigned long flags; + + memset(buf, 0, len); + + spin_lock_irqsave(&i2c->lock, flags); + + i2c->stop_hold = 0; + i2c->is_write = 0; + i2c->rbuf = buf; + i2c->rd_total_len = len; + i2c->rd_data_xfered = 0; + i2c->rd_cmd_xfered = 0; + + if (len <= JZ4780_I2C_FIFO_LEN) + jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1); + else + jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, RX_LEVEL); + + jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL); + + jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, + JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP + | JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF); + + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL); + tmp |= JZ4780_I2C_CTRL_STPHLD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + spin_unlock_irqrestore(&i2c->lock, flags); + + timeout = wait_for_completion_timeout(&i2c->trans_waitq, + msecs_to_jiffies(wait_time)); + + if (!timeout) { + dev_err(&i2c->adap.dev, "irq read timeout\n"); + dev_dbg(&i2c->adap.dev, "send cmd count:%d %d\n", + i2c->cmd, i2c->cmd_buf[i2c->cmd]); + dev_dbg(&i2c->adap.dev, "receive data count:%d %d\n", + i2c->cmd, i2c->data_buf[i2c->cmd]); + ret = -EIO; + } + + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT); + if (tmp) { + jz4780_i2c_txabrt(i2c, tmp); + ret = -EIO; + } + + return ret; +} + +static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c, + unsigned char *buf, int len, + int cnt, int idx) +{ + int ret = 0; + int wait_time = JZ4780_I2C_TIMEOUT * (len + 5); + long timeout; + unsigned short tmp; + unsigned long flags; + + spin_lock_irqsave(&i2c->lock, flags); + + if (idx < (cnt - 1)) + i2c->stop_hold = 1; + else + i2c->stop_hold = 0; + + i2c->is_write = 1; + i2c->wbuf = buf; + i2c->wt_len = len; + + jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL); + + jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP + | JZ4780_I2C_INTM_MTXABT); + + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL); + tmp |= JZ4780_I2C_CTRL_STPHLD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + spin_unlock_irqrestore(&i2c->lock, flags); + + timeout = wait_for_completion_timeout(&i2c->trans_waitq, + msecs_to_jiffies(wait_time)); + if (timeout && !i2c->stop_hold) { + unsigned short i2c_sta; + int write_in_process; + + timeout = JZ4780_I2C_TIMEOUT * 100; + for (; timeout > 0; timeout--) { + i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA); + + write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) || + !(i2c_sta & JZ4780_I2C_STA_TFE); + if (!write_in_process) + break; + udelay(10); + } + } + + if (!timeout) { + dev_err(&i2c->adap.dev, "write wait timeout\n"); + ret = -EIO; + } + + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT); + if (tmp) { + jz4780_i2c_txabrt(i2c, tmp); + ret = -EIO; + } + + return ret; +} + +static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, + int count) +{ + int i = -EIO; + int ret = 0; + struct jz4780_i2c *i2c = adap->algo_data; + + ret = jz4780_i2c_prepare(i2c); + if (ret) { + dev_err(&i2c->adap.dev, "I2C prepare failed\n"); + goto out; + } + + if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) { + ret = jz4780_i2c_set_target(i2c, msg->addr); + if (ret) + goto out; + } + for (i = 0; i < count; i++, msg++) { + if (msg->flags & I2C_M_RD) + ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len, + count, i); + else + ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len, + count, i); + + if (ret) + goto out; + } + + ret = i; + +out: + jz4780_i2c_cleanup(i2c); + return ret; +} + +static u32 jz4780_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm jz4780_i2c_algorithm = { + .master_xfer = jz4780_i2c_xfer, + .functionality = jz4780_i2c_functionality, +}; + +static const struct of_device_id jz4780_i2c_of_matches[] = { + { .compatible = "ingenic,jz4780-i2c", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, jz4780_i2c_of_matches); + +static int jz4780_i2c_probe(struct platform_device *pdev) +{ + int ret = 0; + unsigned int clk_freq = 0; + unsigned short tmp; + struct resource *r; + struct jz4780_i2c *i2c; + + i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &jz4780_i2c_algorithm; + i2c->adap.algo_data = i2c; + i2c->adap.retries = 5; + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.dev.of_node = pdev->dev.of_node; + sprintf(i2c->adap.name, "%s", pdev->name); + + init_completion(&i2c->trans_waitq); + spin_lock_init(&i2c->lock); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + i2c->iomem = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(i2c->iomem)) + return PTR_ERR(i2c->iomem); + + platform_set_drvdata(pdev, i2c); + + i2c->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c->clk)) + return PTR_ERR(i2c->clk); + + ret = clk_prepare_enable(i2c->clk); + if (ret) + return ret; + + ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &clk_freq); + if (ret) { + dev_err(&pdev->dev, "clock-frequency not specified in DT\n"); + goto err; + } + + i2c->speed = clk_freq / 1000; + if (i2c->speed == 0) { + ret = -EINVAL; + dev_err(&pdev->dev, "clock-frequency minimum is 1000\n"); + goto err; + } + jz4780_i2c_set_speed(i2c); + + dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed); + + tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL); + tmp &= ~JZ4780_I2C_CTRL_STPHLD; + jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp); + + jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0); + + ret = platform_get_irq(pdev, 0); + if (ret < 0) + goto err; + i2c->irq = ret; + ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0, + dev_name(&pdev->dev), i2c); + if (ret) + goto err; + + ret = i2c_add_adapter(&i2c->adap); + if (ret < 0) + goto err; + + return 0; + +err: + clk_disable_unprepare(i2c->clk); + return ret; +} + +static int jz4780_i2c_remove(struct platform_device *pdev) +{ + struct jz4780_i2c *i2c = platform_get_drvdata(pdev); + + clk_disable_unprepare(i2c->clk); + i2c_del_adapter(&i2c->adap); + return 0; +} + +static struct platform_driver jz4780_i2c_driver = { + .probe = jz4780_i2c_probe, + .remove = jz4780_i2c_remove, + .driver = { + .name = "jz4780-i2c", + .of_match_table = of_match_ptr(jz4780_i2c_of_matches), + }, +}; + +module_platform_driver(jz4780_i2c_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("ztyan<ztyan@ingenic.cn>"); +MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs"); |