[PATCH v1 1/3] i2c: rk3x: add calc_divs ops for new version

[David Wu]

The calc_divs of new version is different form the old.
The time of tHD;sda, tHD;sda, tSU;sta, tHD;sta and tSU;sto
could be configured by RKI2C_CON register.
So it need a new way to calc_divs for new i2c controller.

Signed-off-by: David Wu <wdc at rock-chips.com>
Signed-off-by: David Wu <david.wu at rock-chips.com>
---

 drivers/i2c/busses/i2c-rk3x.c | 54 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 43 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index c1935eb..0ff299f 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -58,6 +58,12 @@ enum {
 #define REG_CON_LASTACK   BIT(5) /* 1: send NACK after last received byte */
 #define REG_CON_ACTACK    BIT(6) /* 1: stop if NACK is received */
 
+#define VERSION_MASK	  0xffff0000
+#define VERSION_SHIFT	  16
+
+#define RK3X_I2C_V0	  0x0
+#define RK3X_I2C_V1	  0x1
+
 /* REG_MRXADDR bits */
 #define REG_MRXADDR_VALID(x) BIT(24 + (x)) /* [x*8+7:x*8] of MRX[R]ADDR valid */
 
@@ -90,10 +96,22 @@ struct rk3x_i2c_soc_data {
 	int grf_offset;
 };
 
+struct rk3x_i2c_ops {
+	int (*calc_divs)(unsigned long,
+			 unsigned long,
+			 unsigned long,
+			 unsigned long,
+			 unsigned long,
+			 unsigned long *,
+			 unsigned long *,
+			 unsigned int *);
+};
+
 struct rk3x_i2c {
 	struct i2c_adapter adap;
 	struct device *dev;
 	struct rk3x_i2c_soc_data *soc_data;
+	struct rk3x_i2c_ops ops;
 
 	/* Hardware resources */
 	void __iomem *regs;
@@ -116,6 +134,7 @@ struct rk3x_i2c {
 	u8 addr;
 	unsigned int mode;
 	bool is_last_msg;
+	unsigned int time_con;
 
 	/* I2C state machine */
 	enum rk3x_i2c_state state;
@@ -151,7 +170,8 @@ static void rk3x_i2c_start(struct rk3x_i2c *i2c)
 	i2c_writel(i2c, REG_INT_START, REG_IEN);
 
 	/* enable adapter with correct mode, send START condition */
-	val = REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START;
+	val = i2c->time_con | REG_CON_EN | REG_CON_MOD(i2c->mode)
+		| REG_CON_START;
 
 	/* if we want to react to NACK, set ACTACK bit */
 	if (!(i2c->msg->flags & I2C_M_IGNORE_NAK))
@@ -443,16 +463,19 @@ out:
  * @sda_fall_ns: How many ns it takes for SDA to fall.
  * @div_low: Divider output for low
  * @div_high: Divider output for high
+ * @con: version0 is not used
  *
  * Returns: 0 on success, -EINVAL if the goal SCL rate is too slow. In that case
  * a best-effort divider value is returned in divs. If the target rate is
  * too high, we silently use the highest possible rate.
  */
-static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
-			      unsigned long scl_rise_ns,
-			      unsigned long scl_fall_ns,
-			      unsigned long sda_fall_ns,
-			      unsigned long *div_low, unsigned long *div_high)
+static int rk3x_i2c_v0_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
+				 unsigned long scl_rise_ns,
+				 unsigned long scl_fall_ns,
+				 unsigned long sda_fall_ns,
+				 unsigned long *div_low,
+				 unsigned long *div_high,
+				 unsigned int *con)
 {
 	unsigned long spec_min_low_ns, spec_min_high_ns;
 	unsigned long spec_setup_start, spec_max_data_hold_ns;
@@ -616,17 +639,19 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
 
 static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 {
+	unsigned int con = 0;
 	unsigned long div_low, div_high;
 	u64 t_low_ns, t_high_ns;
 	int ret;
 
-	ret = rk3x_i2c_calc_divs(clk_rate, i2c->scl_frequency, i2c->scl_rise_ns,
+	ret = i2c->ops.calc_divs(clk_rate, i2c->scl_frequency, i2c->scl_rise_ns,
 				 i2c->scl_fall_ns, i2c->sda_fall_ns,
-				 &div_low, &div_high);
+				 &div_low, &div_high, &con);
 	WARN_ONCE(ret != 0, "Could not reach SCL freq %u", i2c->scl_frequency);
 
 	clk_enable(i2c->clk);
 	i2c_writel(i2c, (div_high << 16) | (div_low & 0xffff), REG_CLKDIV);
+	i2c->time_con = con;
 	clk_disable(i2c->clk);
 
 	t_low_ns = div_u64(((u64)div_low + 1) * 8 * 1000000000, clk_rate);
@@ -661,13 +686,14 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
 	struct clk_notifier_data *ndata = data;
 	struct rk3x_i2c *i2c = container_of(nb, struct rk3x_i2c, clk_rate_nb);
 	unsigned long div_low, div_high;
+	unsigned int con = 0;
 
 	switch (event) {
 	case PRE_RATE_CHANGE:
-		if (rk3x_i2c_calc_divs(ndata->new_rate, i2c->scl_frequency,
+		if (i2c->ops.calc_divs(ndata->new_rate, i2c->scl_frequency,
 				       i2c->scl_rise_ns, i2c->scl_fall_ns,
 				       i2c->sda_fall_ns,
-				       &div_low, &div_high) != 0)
+				       &div_low, &div_high, &con) != 0)
 			return NOTIFY_STOP;
 
 		/* scale up */
@@ -816,7 +842,8 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
 
 			/* Force a STOP condition without interrupt */
 			i2c_writel(i2c, 0, REG_IEN);
-			i2c_writel(i2c, REG_CON_EN | REG_CON_STOP, REG_CON);
+			i2c_writel(i2c, i2c->time_con | REG_CON_EN |
+				   REG_CON_STOP, REG_CON);
 
 			i2c->state = STATE_IDLE;
 
@@ -871,6 +898,7 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 	u32 value;
 	int irq;
 	unsigned long clk_rate;
+	unsigned int version;
 
 	i2c = devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL);
 	if (!i2c)
@@ -983,6 +1011,10 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, i2c);
 
+	version = (readl(i2c->regs + REG_CON) & VERSION_MASK) >> VERSION_SHIFT;
+	if (version == RK3X_I2C_V0)
+		i2c->ops.calc_divs = rk3x_i2c_v0_calc_divs;
+
 	ret = clk_prepare(i2c->clk);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Could not prepare clock\n");
-- 
1.9.1