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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi David:

It's better to add a cover-letter, and add changes note for new version,
such as:

changes since v0:
- split patch to two patches or more, one patch for one new feature (Heiko)

and NOT to have two same signed-off-by

在 11/12/2015 22:33, David Wu 写道:
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@xxxxxxxxxxxxxx>
Signed-off-by: David Wu <david.wu@xxxxxxxxxxxxxx>
---

  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");


--
****************************************************************************
许剑群
Fuzhou Rockchip Electronics Co., Ltd
地址:福建省福州市铜盘路软件大道89号软件园A区21号楼
ADDR: No.21 bldg, Fuzhou Software Park,Fuzhou,Fujian,P.R.China
Email: xjq@xxxxxxxxxxxxxx
****************************************************************************
保密提示:本邮件及其附件含有机密信息来自福州瑞芯微电子股份有限公司,仅发 送给本邮件所指特定收件人。若非该特定收件人,请勿复制、 使用或披露本邮件 的任何内容。若误收本邮件,请从系统中永久性删除本邮件及所有附件,并以回复 邮件或其他方式即刻告知发件人。福州瑞芯微电子有限公司拥有本邮件信息的著作 权及解释权,禁止任何未经授权许可的侵权行为。 IMPORTANT NOTICE: This email is from Fuzhou Rockchip Electronics Co., Ltd .The contents of this email and any attachments may contain information that is privileged, confidential and/or exempt from disclosure under applicable law and relevant NDA. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information is STRICTLY PROHIBITED. Please immediately contact the sender as soon as possible and destroy the material in its entirety in any format. Thank you.
****************************************************************************

--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux