Hello Heiko,
thank you for your proposals. I'll make the appropriate changes.
Regards Stefan
Am 03.07.20 um 08:03 schrieb Heiko Schocher:
Hello Stefan,
Am 29.06.2020 um 19:46 schrieb Stefan Bosch:
Changes in relation to FriendlyARM's U-Boot nanopi2-v2016.01:
- i2c/nx_i2c.c: Some adaptions mainly because of changes in
"struct udevice".
- several Bugfixes in nx_i2c.c.
- the driver has been for s5p6818 only. Code extended appropriately
in order s5p4418 is also working.
- "probe_chip" added.
- pinctrl-driver/dt is used instead of configuring the i2c I/O-pins
in the i2c-driver.
- '#ifdef CONFIG...' changed to 'if (IS_ENABLED(CONFIG...))' where
possible (and similar).
- livetree API (dev_read_...) is used instead of fdt one (fdt...).
Signed-off-by: Stefan Bosch stefan_b@posteo.net
Reviewed-by: Heiko Schocher hs@denx.de
Nitpick only ...
[...]
diff --git a/drivers/i2c/nx_i2c.c b/drivers/i2c/nx_i2c.c new file mode 100644 index 0000000..cefc774 --- /dev/null +++ b/drivers/i2c/nx_i2c.c @@ -0,0 +1,624 @@
[...]
+static uint i2c_set_clk(struct nx_i2c_bus *bus, uint enb) +{ + struct clk *clk; + char name[50];
+ sprintf(name, "%s.%d", DEV_NAME_I2C, bus->bus_num); + clk = clk_get((const char *)name); + if (!clk) { + debug("%s(): clk_get(%s) error!\n", + __func__, (const char *)name); + return -EINVAL; + }
+ if (enb) { + clk_disable(clk); + clk_enable(clk); + } else { + clk_disable(clk); + }
You can do here:
clk_disable(clk); if (enb) clk_enable(clk);
+ return 0; +}
+#ifdef CONFIG_ARCH_S5P6818 +/* Set SDA line delay, not available at S5P4418 */ +static int nx_i2c_set_sda_delay(struct nx_i2c_bus *bus) +{ + struct nx_i2c_regs *i2c = bus->regs; + uint pclk = 0; + uint t_pclk = 0; + uint delay = 0;
+ /* get input clock of the I2C-controller */ + pclk = i2c_get_clkrate(bus);
+ if (bus->sda_delay) { + /* t_pclk = period time of one pclk [ns] */ + t_pclk = DIV_ROUND_UP(1000, pclk / 1000000); + /* delay = number of pclks required for sda_delay [ns] */ + delay = DIV_ROUND_UP(bus->sda_delay, t_pclk); + /* delay = register value (step of 5 clocks) */ + delay = DIV_ROUND_UP(delay, 5); + /* max. possible register value = 3 */ + if (delay > 3) {
May you use defines here?
+ delay = 3; + debug("%s(): sda-delay des.: %dns, sat. to max.: %dns (granularity: %dns)\n", + __func__, bus->sda_delay, t_pclk * delay * 5, + t_pclk * 5); + } else { + debug("%s(): sda-delay des.: %dns, act.: %dns (granularity: %dns)\n", + __func__, bus->sda_delay, t_pclk * delay * 5, + t_pclk * 5); + }
+ delay |= I2CLC_FILTER; + } else { + delay = 0; + debug("%s(): sda-delay = 0\n", __func__); + }
+ delay &= 0x7; + writel(delay, &i2c->iiclc);
+ return 0; +} +#endif
+static int nx_i2c_set_bus_speed(struct udevice *dev, uint speed) +{ + struct nx_i2c_bus *bus = dev_get_priv(dev); + struct nx_i2c_regs *i2c = bus->regs; + unsigned long pclk, pres = 16, div;
+ if (i2c_set_clk(bus, 1)) + return -EINVAL;
+ /* get input clock of the I2C-controller */ + pclk = i2c_get_clkrate(bus);
+ /* calculate prescaler and divisor values */ + if ((pclk / pres / (16 + 1)) > speed) + /* set prescaler to 256 */ + pres = 256;
+ div = 0; + /* actual divider = div + 1 */ + while ((pclk / pres / (div + 1)) > speed) + div++;
+ if (div > 0xF) { + debug("%s(): pres==%ld, div==0x%lx is saturated to 0xF !)\n", + __func__, pres, div); + div = 0xF; + } else { + debug("%s(): pres==%ld, div==0x%lx)\n", __func__, pres, div); + }
+ /* set prescaler, divisor according to pclk, also set ACKGEN, IRQ */ + writel((div & 0x0F) | ((pres == 256) ? 0x40 : 0), &i2c->iiccon);
Ok, I am really nitpicking now ... can you use defines here instead this magic values?
[...]
Thanks!
bye, Heiko