[PATCH v1 1/3] i2c: rk3x: add calc_divs ops for new version
Jianqun Xu
jay.xu at rock-chips.com
Mon Dec 14 16:32:44 PST 2015
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 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");
>
--
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