From b2ed11e224a28b896b52c109657d183059f7a53f Mon Sep 17 00:00:00 2001 From: Eddie Huang Date: Thu, 21 May 2015 16:53:30 +0800 Subject: [PATCH] I2C: mediatek: Add driver for MediaTek MT8173 I2C controller Add mediatek MT8173 I2C controller driver. Compare to I2C controller of earlier mediatek SoC, MT8173 fix write-then-read limitation, and also increase message size to 64kb. Signed-off-by: Xudong Chen Signed-off-by: Liguo Zhang Signed-off-by: Eddie Huang Acked-by: Sascha Hauer Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-mt65xx.c | 103 +++++++++++++++++++++++++++++----------- 1 file changed, 74 insertions(+), 29 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index b1d2d7c..9920eef 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -33,10 +33,13 @@ #include #include +#define I2C_RS_TRANSFER (1 << 4) #define I2C_HS_NACKERR (1 << 2) #define I2C_ACKERR (1 << 1) #define I2C_TRANSAC_COMP (1 << 0) #define I2C_TRANSAC_START (1 << 0) +#define I2C_RS_MUL_CNFG (1 << 15) +#define I2C_RS_MUL_TRIG (1 << 14) #define I2C_DCM_DISABLE 0x0000 #define I2C_IO_CONFIG_OPEN_DRAIN 0x0003 #define I2C_IO_CONFIG_PUSH_PULL 0x0000 @@ -126,6 +129,7 @@ struct mtk_i2c_compatible { const struct i2c_adapter_quirks *quirks; unsigned char pmic_i2c: 1; unsigned char dcm: 1; + unsigned char auto_restart: 1; }; struct mtk_i2c { @@ -159,21 +163,39 @@ static const struct i2c_adapter_quirks mt6577_i2c_quirks = { .max_comb_2nd_msg_len = 31, }; +static const struct i2c_adapter_quirks mt8173_i2c_quirks = { + .max_num_msgs = 65535, + .max_write_len = 65535, + .max_read_len = 65535, + .max_comb_1st_msg_len = 65535, + .max_comb_2nd_msg_len = 65535, +}; + static const struct mtk_i2c_compatible mt6577_compat = { .quirks = &mt6577_i2c_quirks, .pmic_i2c = 0, .dcm = 1, + .auto_restart = 0, }; static const struct mtk_i2c_compatible mt6589_compat = { .quirks = &mt6577_i2c_quirks, .pmic_i2c = 1, .dcm = 0, + .auto_restart = 0, +}; + +static const struct mtk_i2c_compatible mt8173_compat = { + .quirks = &mt8173_i2c_quirks, + .pmic_i2c = 0, + .dcm = 1, + .auto_restart = 1, }; static const struct of_device_id mtk_i2c_of_match[] = { { .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat }, { .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat }, + { .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat }, {} }; MODULE_DEVICE_TABLE(of, mtk_i2c_of_match); @@ -332,21 +354,27 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk, return 0; } -static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs) +static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, + int num, int left_num) { u16 addr_reg; + u16 start_reg; u16 control_reg; + u16 restart_flag = 0; dma_addr_t rpaddr = 0; dma_addr_t wpaddr = 0; int ret; i2c->irq_stat = 0; + if (i2c->dev_comp->auto_restart) + restart_flag = I2C_RS_TRANSFER; + reinit_completion(&i2c->msg_complete); control_reg = readw(i2c->base + OFFSET_CONTROL) & ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS); - if (i2c->speed_hz > 400000) + if ((i2c->speed_hz > 400000) || (left_num >= 1)) control_reg |= I2C_CONTROL_RS; if (i2c->op == I2C_MASTER_WRRD) @@ -367,13 +395,13 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs) writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR); /* Clear interrupt status */ - writew(I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP, - i2c->base + OFFSET_INTR_STAT); + writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT); writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR); /* Enable interrupt */ - writew(I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP, - i2c->base + OFFSET_INTR_MASK); + writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK); /* Set transfer and transaction len */ if (i2c->op == I2C_MASTER_WRRD) { @@ -382,7 +410,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs) writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN); } else { writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN); - writew(I2C_RD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN); + writew(num, i2c->base + OFFSET_TRANSAC_LEN); } /* Prepare buffer data to start transfer */ @@ -426,13 +454,21 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs) } writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN); - writew(I2C_TRANSAC_START, i2c->base + OFFSET_START); + + if (!i2c->dev_comp->auto_restart) { + start_reg = I2C_TRANSAC_START; + } else { + start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG; + if (left_num >= 1) + start_reg |= I2C_RS_MUL_CNFG; + } + writew(start_reg, i2c->base + OFFSET_START); ret = wait_for_completion_timeout(&i2c->msg_complete, i2c->adap.timeout); /* Clear interrupt mask */ - writew(~(I2C_HS_NACKERR | I2C_ACKERR | + writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK); if (i2c->op == I2C_MASTER_WR) { @@ -476,28 +512,33 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap, if (ret) return ret; - if (!msgs->buf) { - dev_dbg(i2c->dev, "data buffer is NULL.\n"); - ret = -EINVAL; - goto err_exit; - } - - if (msgs->flags & I2C_M_RD) - i2c->op = I2C_MASTER_RD; - else - i2c->op = I2C_MASTER_WR; + while (left_num--) { + if (!msgs->buf) { + dev_dbg(i2c->dev, "data buffer is NULL.\n"); + ret = -EINVAL; + goto err_exit; + } - if (num > 1) { - /* combined two messages into one transaction */ - i2c->op = I2C_MASTER_WRRD; - left_num--; - } + if (msgs->flags & I2C_M_RD) + i2c->op = I2C_MASTER_RD; + else + i2c->op = I2C_MASTER_WR; + + if (!i2c->dev_comp->auto_restart) { + if (num > 1) { + /* combined two messages into one transaction */ + i2c->op = I2C_MASTER_WRRD; + left_num--; + } + } - /* always use DMA mode. */ - ret = mtk_i2c_do_transfer(i2c, msgs); - if (ret < 0) - goto err_exit; + /* always use DMA mode. */ + ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num); + if (ret < 0) + goto err_exit; + msgs++; + } /* the return value is number of executed messages */ ret = num; @@ -509,9 +550,13 @@ err_exit: static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id) { struct mtk_i2c *i2c = dev_id; + u16 restart_flag = 0; + + if (i2c->dev_comp->auto_restart) + restart_flag = I2C_RS_TRANSFER; i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT); - writew(I2C_HS_NACKERR | I2C_ACKERR + writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT); complete(&i2c->msg_complete); -- 2.7.4