From 1ab92956d4aac52d0c59c229a0790a672063ece0 Mon Sep 17 00:00:00 2001 From: David Wu Date: Thu, 17 Mar 2016 00:57:17 +0800 Subject: i2c: rk3x: switch to i2c generic dt parsing Switch to the new generic functions: i2c_parse_fw_timings(). Signed-off-by: David Wu Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-rk3x.c | 87 ++++++++++++------------------------------- 1 file changed, 24 insertions(+), 63 deletions(-) (limited to 'drivers/i2c/busses/i2c-rk3x.c') diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index 9096d17..c4b0d89 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -101,10 +101,7 @@ struct rk3x_i2c { struct notifier_block clk_rate_nb; /* Settings */ - unsigned int scl_frequency; - unsigned int scl_rise_ns; - unsigned int scl_fall_ns; - unsigned int sda_fall_ns; + struct i2c_timings t; /* Synchronization & notification */ spinlock_t lock; @@ -437,10 +434,7 @@ out: * Calculate divider values for desired SCL frequency * * @clk_rate: I2C input clock rate - * @scl_rate: Desired SCL rate - * @scl_rise_ns: How many ns it takes for SCL to rise. - * @scl_fall_ns: How many ns it takes for SCL to fall. - * @sda_fall_ns: How many ns it takes for SDA to fall. + * @t: Known I2C timing information. * @div_low: Divider output for low * @div_high: Divider output for high * @@ -448,11 +442,10 @@ out: * 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_calc_divs(unsigned long clk_rate, + struct i2c_timings *t, + unsigned long *div_low, + unsigned long *div_high) { unsigned long spec_min_low_ns, spec_min_high_ns; unsigned long spec_setup_start, spec_max_data_hold_ns; @@ -472,12 +465,12 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate, int ret = 0; /* Only support standard-mode and fast-mode */ - if (WARN_ON(scl_rate > 400000)) - scl_rate = 400000; + if (WARN_ON(t->bus_freq_hz > 400000)) + t->bus_freq_hz = 400000; /* prevent scl_rate_khz from becoming 0 */ - if (WARN_ON(scl_rate < 1000)) - scl_rate = 1000; + if (WARN_ON(t->bus_freq_hz < 1000)) + t->bus_freq_hz = 1000; /* * min_low_ns: The minimum number of ns we need to hold low to @@ -491,7 +484,7 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate, * This is because the i2c host on Rockchip holds the data line * for half the low time. */ - if (scl_rate <= 100000) { + if (t->bus_freq_hz <= 100000) { /* Standard-mode */ spec_min_low_ns = 4700; spec_setup_start = 4700; @@ -506,7 +499,7 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate, spec_max_data_hold_ns = 900; data_hold_buffer_ns = 50; } - min_high_ns = scl_rise_ns + spec_min_high_ns; + min_high_ns = t->scl_rise_ns + spec_min_high_ns; /* * Timings for repeated start: @@ -517,18 +510,18 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate, * we meet tSU;STA and tHD;STA times. */ min_high_ns = max(min_high_ns, - DIV_ROUND_UP((scl_rise_ns + spec_setup_start) * 1000, 875)); + DIV_ROUND_UP((t->scl_rise_ns + spec_setup_start) * 1000, 875)); min_high_ns = max(min_high_ns, - DIV_ROUND_UP((scl_rise_ns + spec_setup_start + - sda_fall_ns + spec_min_high_ns), 2)); + DIV_ROUND_UP((t->scl_rise_ns + spec_setup_start + + t->sda_fall_ns + spec_min_high_ns), 2)); - min_low_ns = scl_fall_ns + spec_min_low_ns; + min_low_ns = t->scl_fall_ns + spec_min_low_ns; max_low_ns = spec_max_data_hold_ns * 2 - data_hold_buffer_ns; min_total_ns = min_low_ns + min_high_ns; /* Adjust to avoid overflow */ clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000); - scl_rate_khz = scl_rate / 1000; + scl_rate_khz = t->bus_freq_hz / 1000; /* * We need the total div to be >= this number @@ -616,14 +609,13 @@ 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) { + struct i2c_timings *t = &i2c->t; 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, - i2c->scl_fall_ns, i2c->sda_fall_ns, - &div_low, &div_high); - WARN_ONCE(ret != 0, "Could not reach SCL freq %u", i2c->scl_frequency); + ret = rk3x_i2c_calc_divs(clk_rate, t, &div_low, &div_high); + WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz); clk_enable(i2c->clk); i2c_writel(i2c, (div_high << 16) | (div_low & 0xffff), REG_CLKDIV); @@ -634,7 +626,7 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate) dev_dbg(i2c->dev, "CLK %lukhz, Req %uns, Act low %lluns high %lluns\n", clk_rate / 1000, - 1000000000 / i2c->scl_frequency, + 1000000000 / t->bus_freq_hz, t_low_ns, t_high_ns); } @@ -664,9 +656,7 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long switch (event) { case PRE_RATE_CHANGE: - if (rk3x_i2c_calc_divs(ndata->new_rate, i2c->scl_frequency, - i2c->scl_rise_ns, i2c->scl_fall_ns, - i2c->sda_fall_ns, + if (rk3x_i2c_calc_divs(ndata->new_rate, &i2c->t, &div_low, &div_high) != 0) return NOTIFY_STOP; @@ -879,37 +869,8 @@ static int rk3x_i2c_probe(struct platform_device *pdev) match = of_match_node(rk3x_i2c_match, np); i2c->soc_data = (struct rk3x_i2c_soc_data *)match->data; - if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", - &i2c->scl_frequency)) { - dev_info(&pdev->dev, "using default SCL frequency: %d\n", - DEFAULT_SCL_RATE); - i2c->scl_frequency = DEFAULT_SCL_RATE; - } - - if (i2c->scl_frequency == 0 || i2c->scl_frequency > 400 * 1000) { - dev_warn(&pdev->dev, "invalid SCL frequency specified.\n"); - dev_warn(&pdev->dev, "using default SCL frequency: %d\n", - DEFAULT_SCL_RATE); - i2c->scl_frequency = DEFAULT_SCL_RATE; - } - - /* - * Read rise and fall time from device tree. If not available use - * the default maximum timing from the specification. - */ - if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-rising-time-ns", - &i2c->scl_rise_ns)) { - if (i2c->scl_frequency <= 100000) - i2c->scl_rise_ns = 1000; - else - i2c->scl_rise_ns = 300; - } - if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-falling-time-ns", - &i2c->scl_fall_ns)) - i2c->scl_fall_ns = 300; - if (of_property_read_u32(pdev->dev.of_node, "i2c-sda-falling-time-ns", - &i2c->sda_fall_ns)) - i2c->sda_fall_ns = i2c->scl_fall_ns; + /* use common interface to get I2C timing properties */ + i2c_parse_fw_timings(&pdev->dev, &i2c->t, true); strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name)); i2c->adap.owner = THIS_MODULE; -- cgit v1.1