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i2c: designware: refactoring of the i2c-designware
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- Factor out all _master() part of code from i2c-designware-core
  and i2c-designware-platdrv to separate functions.
- Standardize all code related with MASTER mode.
- I have to take off DW_IC_INTR_TX_EMPTY from DW_IC_INTR_DEFAULT_MASK
  because it is master specific.

The purpose of this is to prepare the controller to have is I2C MASTER
flow in a separate driver. To do this first all the
functions/definitions related to the MASTER flow were identified.

Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Luis Oliveira authored and Wolfram Sang committed Jun 19, 2017
1 parent e393f67 commit 89a1e1b
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Showing 2 changed files with 52 additions and 35 deletions.
56 changes: 34 additions & 22 deletions drivers/i2c/busses/i2c-designware-core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -87,10 +87,10 @@
#define DW_IC_INTR_GEN_CALL 0x800

#define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
DW_IC_INTR_TX_EMPTY | \
DW_IC_INTR_TX_ABRT | \
DW_IC_INTR_STOP_DET)

#define DW_IC_INTR_MASTER_MASK (DW_IC_INTR_DEFAULT_MASK | \
DW_IC_INTR_TX_EMPTY)
#define DW_IC_STATUS_ACTIVITY 0x1

#define DW_IC_SDA_HOLD_RX_SHIFT 16
Expand Down Expand Up @@ -202,6 +202,16 @@ static void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
}
}

static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
{
/* Configure Tx/Rx FIFO threshold levels */
dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
dw_writel(dev, 0, DW_IC_RX_TL);

/* Configure the I2C master */
dw_writel(dev, dev->master_cfg, DW_IC_CON);
}

static u32
i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
{
Expand Down Expand Up @@ -440,13 +450,7 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
"Hardware too old to adjust SDA hold time.\n");
}

/* Configure Tx/Rx FIFO threshold levels */
dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
dw_writel(dev, 0, DW_IC_RX_TL);

/* Configure the I2C master */
dw_writel(dev, dev->master_cfg , DW_IC_CON);

i2c_dw_configure_fifo_master(dev);
i2c_dw_release_lock(dev);

return 0;
Expand Down Expand Up @@ -511,7 +515,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)

/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK);
dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
}

/*
Expand All @@ -531,7 +535,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
u8 *buf = dev->tx_buf;
bool need_restart = false;

intr_mask = DW_IC_INTR_DEFAULT_MASK;
intr_mask = DW_IC_INTR_MASTER_MASK;

for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
u32 flags = msgs[dev->msg_write_idx].flags;
Expand Down Expand Up @@ -881,22 +885,14 @@ static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
}

/*
* Interrupt service routine. This gets called whenever an I2C interrupt
* Interrupt service routine. This gets called whenever an I2C master interrupt
* occurs.
*/
static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
{
struct dw_i2c_dev *dev = dev_id;
u32 stat, enabled;

enabled = dw_readl(dev, DW_IC_ENABLE);
stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
dev_dbg(dev->dev, "%s: enabled=%#x stat=%#x\n", __func__, enabled, stat);
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return IRQ_NONE;
u32 stat;

stat = i2c_dw_read_clear_intrbits(dev);

if (stat & DW_IC_INTR_TX_ABRT) {
dev->cmd_err |= DW_IC_ERR_TX_ABRT;
dev->status = STATUS_IDLE;
Expand Down Expand Up @@ -931,6 +927,22 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
dw_writel(dev, stat, DW_IC_INTR_MASK);
}

return 0;
}

static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
u32 stat, enabled;

enabled = dw_readl(dev, DW_IC_ENABLE);
stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return IRQ_NONE;

i2c_dw_irq_handler_master(dev);

return IRQ_HANDLED;
}

Expand Down
31 changes: 18 additions & 13 deletions drivers/i2c/busses/i2c-designware-platdrv.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -172,6 +172,23 @@ static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
}
#endif

static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
{
dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN;

switch (dev->clk_freq) {
case 100000:
dev->master_cfg |= DW_IC_CON_SPEED_STD;
break;
case 3400000:
dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
break;
default:
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
}
}

static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
{
if (IS_ERR(i_dev->clk))
Expand Down Expand Up @@ -287,19 +304,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)

dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;

dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN;

switch (dev->clk_freq) {
case 100000:
dev->master_cfg |= DW_IC_CON_SPEED_STD;
break;
case 3400000:
dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
break;
default:
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
}
i2c_dw_configure_master(dev);

dev->clk = devm_clk_get(&pdev->dev, NULL);
if (!i2c_dw_plat_prepare_clk(dev, true)) {
Expand Down

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