[PATCH v8 2/6] i2c: designware: refactoring of the i2c-designware

From: Luis Oliveira
Date: Wed Apr 12 2017 - 12:50:11 EST


- 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@xxxxxxxxxxxx>
Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
---
v7-v8
- no changes

drivers/i2c/busses/i2c-designware-core.c | 56 +++++++++++++++++------------
drivers/i2c/busses/i2c-designware-platdrv.c | 31 +++++++++-------
2 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index c0e9cf374e2b..ce5d11102070 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -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
@@ -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)
{
@@ -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;
@@ -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);
}

/*
@@ -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;
@@ -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;
@@ -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;
}

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index ee587f872ef8..7dece6f325d4 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -155,6 +155,23 @@ 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))
@@ -270,19 +287,7 @@ 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)) {
--
2.11.0