On 10/9/22 20:31, Jonathan Cameron wrote:
On Thu, 6 Oct 2022 17:07:37 +0300
Cosmin Tanislav <demonsingur@xxxxxxxxx> wrote:
AD4130-8 is an ultra-low power, high precision, measurement solution for
low bandwidth battery operated applications.
The fully integrated AFE (Analog Front-End) includes a multiplexer for up
to 16 single-ended or 8 differential inputs, PGA (Programmable Gain
Amplifier), 24-bit Sigma-Delta ADC, on-chip reference and oscillator,
selectable filter options, smart sequencer, sensor biasing and excitation
options, diagnostics, and a FIFO buffer.
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Hi Cosmin,
I've cropped down (mostly) to the clock changes.
A few minor things in there + this looks like it would suffer from the issue
with IIO_CONST_ATTR() not being handled correctly for buffer attributes.
Jonathan
+static IIO_CONST_ATTR(hwfifo_watermark_min, "1");
+static IIO_CONST_ATTR(hwfifo_watermark_max, __stringify(AD4130_FIFO_SIZE));
These look like they'd suffer from same problem
https://lore.kernel.org/all/cover.1664782676.git.mazziesaccount@xxxxxxxxx/
tackles. Short term fix is don't use IIO_CONST_ATTR for buffer attributes.
Right, this only works downstream.
Should I switch to IIO_STATIC_CONST_DEVICE_ATTR?
+static IIO_DEVICE_ATTR_RO(hwfifo_watermark, 0);
+static IIO_DEVICE_ATTR_RO(hwfifo_enabled, 0);
+
+static const struct attribute *ad4130_fifo_attributes[] = {
+ &iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
+ &iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
+ &iio_dev_attr_hwfifo_watermark.dev_attr.attr,
+ &iio_dev_attr_hwfifo_enabled.dev_attr.attr,
+ NULL
+};
+static void ad4130_clk_disable_unprepare(void *clk)
+{
+ clk_disable_unprepare(clk);
+}
+
+static int ad4130_set_mclk_sel(struct ad4130_state *st,
+ enum ad4130_mclk_sel mclk_sel)
+{
+ return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
+ AD4130_ADC_CONTROL_MCLK_SEL_MASK,
+ FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK,
+ mclk_sel));
+}
+
+static unsigned long ad4130_int_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return AD4130_MCLK_FREQ_76_8KHZ;
+}
+
+static int ad4130_int_clk_is_enabled(struct clk_hw *hw)
+{
+ struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
+
+ return st->mclk_sel == AD4130_MCLK_76_8KHZ_OUT;
+}
+
+static int ad4130_int_clk_prepare(struct clk_hw *hw)
+{
+ struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
+ int ret;
+
+ ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ_OUT);
+ if (ret)
+ return ret;
+
+ st->mclk_sel = AD4130_MCLK_76_8KHZ_OUT;
+
+ return 0;
+}
+
+static void ad4130_int_clk_unprepare(struct clk_hw *hw)
+{
+ struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
+ int ret;
+
+ ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ);
+ if (ret)
+ return;
+
+ st->mclk_sel = AD4130_MCLK_76_8KHZ;
+}
+
+static const struct clk_ops ad4130_int_clk_ops = {
+ .recalc_rate = ad4130_int_clk_recalc_rate,
+ .is_enabled = ad4130_int_clk_is_enabled,
+ .prepare = ad4130_int_clk_prepare,
+ .unprepare = ad4130_int_clk_unprepare,
+};
+
+static int ad4130_setup_int_clk(struct ad4130_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ struct device_node *of_node = dev->of_node;
Hmm. There goes our careful use of generic firmware properties.
I guess there still isn't much we can do about that for clks
so at least it's contained to this one function.
Also is this code safe to of_node == NULL?
No, I guess it is not. I'll fix it.
Should I just
if (!of_node) return 0;
?
+ struct clk_init_data init;
+ const char *clk_name;
+ struct clk *clk;
+
+ if (st->int_pin_sel == AD4130_INT_PIN_CLK ||
+ st->mclk_sel != AD4130_MCLK_76_8KHZ)
+ return 0;
+
+ clk_name = of_node->name;
+ of_property_read_string(of_node, "clock-output-names", &clk_name);
Probably want to check success of that read before using it.
I'd also expect that these to be optional + doesn't he dt binding need
updating to add this stuff?
It does need updating, sorry.
of_node->name is the default clk_name, if clock-output-names is present
then the of_property_read_string() result will be used instead. If not,
there's no trouble, and we don't care about the return value since we
have the default clk_name assigned just above.
I can also switch to device_property_read_string() here to minimize the
damage from using OF.
+
+ init.name = clk_name;
+ init.ops = &ad4130_int_clk_ops;
+
+ st->int_clk_hw.init = &init;
+ clk = devm_clk_register(dev, &st->int_clk_hw);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ return of_clk_add_provider(of_node, of_clk_src_simple_get, clk);
+}
+
