Hi Lee,
lee.jones@xxxxxxxxxx wrote on Wed, 22 Sep 2021 17:00:20 +0100:
> On Wed, 15 Sep 2021, Miquel Raynal wrote:
>
> > Introduce a new compatible that has another set of driver data,
> > targeting am437x SoCs with a magnetic reader instead of the
> > touchscreen and a more featureful set of registers.
> >
> > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> > ---
> > drivers/mfd/ti_am335x_tscadc.c | 41 ++++++++++++++++++++++++----
> > include/linux/mfd/ti_am335x_tscadc.h | 7 +++++
> > 2 files changed, 42 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> > index 65c0fa735a71..155a8ed879b3 100644
> > --- a/drivers/mfd/ti_am335x_tscadc.c
> > +++ b/drivers/mfd/ti_am335x_tscadc.c
> > @@ -121,11 +121,11 @@ static int ti_tscadc_probe(struct platform_device *pdev)
> > struct mfd_cell *cell;
> > struct property *prop;
> > const __be32 *cur;
> > - bool use_tsc = false;
> > + bool use_tsc = false, use_mag = false;
> > u32 val;
> > int err;
> > int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels;
> > - int readouts = 0;
> > + int readouts = 0, mag_tracks = 0;
> >
> > /* Allocate memory for device */
> > tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL);
> > @@ -148,6 +148,16 @@ static int ti_tscadc_probe(struct platform_device *pdev)
> > of_node_put(node);
> > if (tscmag_wires)
> > use_tsc = true;
> > + } else {
> > + /*
> > + * When adding support for the magnetic reader, here is the
> > + * place to look for the number of tracks used from device tree.
> > + * Let's default to 0 for now.
> > + */
> > + mag_tracks = 0;
> > + tscmag_wires = mag_tracks * 2;
> > + if (tscmag_wires)
> > + use_mag = true;
> > }
> >
> > node = of_get_child_by_name(pdev->dev.of_node, "adc");
> > @@ -209,8 +219,9 @@ static int ti_tscadc_probe(struct platform_device *pdev)
> > * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK.
> > * ADCs produce a 12-bit sample every 15 ADC_CLK cycles.
> > * am33xx ADCs expect to capture 200ksps.
> > - * We need the ADC clocks to run at 3MHz.
> > - * This frequency is valid since TSC_ADC_SS controller design
> > + * am47xx ADCs expect to capture 867ksps.
> > + * We need ADC clocks respectively running at 3MHz and 13MHz.
> > + * These frequencies are valid since TSC_ADC_SS controller design
> > * assumes the OCP clock is at least 6x faster than the ADC clock.
> > */
> > clk = devm_clk_get(&pdev->dev, NULL);
> > @@ -238,6 +249,9 @@ static int ti_tscadc_probe(struct platform_device *pdev)
> > else
> > tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
> > }
> > + } else {
> > + tscadc->ctrl |= CNTRLREG_MAG_PREAMP_PWRDOWN |
> > + CNTRLREG_MAG_PREAMP_BYPASS;
> > }
> > regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
> >
> > @@ -246,7 +260,7 @@ static int ti_tscadc_probe(struct platform_device *pdev)
> > /* Enable the TSC module enable bit */
> > regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
> >
> > - /* TSC Cell */
> > + /* TSC or MAG Cell */
> > if (tscmag_wires > 0) {
> > cell = &tscadc->cells[cell_idx++];
> > cell->name = tscadc->data->name_tscmag;
> > @@ -334,6 +348,7 @@ static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);
> >
> > static const struct ti_tscadc_data tscdata = {
> > .has_tsc = true,
> > + .has_mag = false,
> > .name_tscmag = "TI-am335x-tsc",
> > .compat_tscmag = "ti,am3359-tsc",
> > .name_adc = "TI-am335x-adc",
> > @@ -341,11 +356,25 @@ static const struct ti_tscadc_data tscdata = {
> > .target_clk_rate = TSC_ADC_CLK,
> > };
> >
> > +static const struct ti_tscadc_data magdata = {
> > + .has_tsc = false,
> > + .has_mag = true,
>
> Why 2 bools?
>
> Better to have a single u8:
>
> MODE_TOUCHSCREEN
> MODE_MAG_STRING
> MODE_NONE
It's not a mode like "please use this feature", it is more like a
feature that is present and we need to know which one it is.
Anyway, I can use an enum for this, fine.
>
> > + .name_tscmag = "TI-am43xx-mag",
> > + .compat_tscmag = "ti,am4372-mag",
> > + .name_adc = "TI-am43xx-adc",
> > + .compat_adc = "ti,am4372-adc",
> > + .target_clk_rate = MAG_ADC_CLK,
> > +};
> > +
> > static const struct of_device_id ti_tscadc_dt_ids[] = {
> > {
> > .compatible = "ti,am3359-tscadc",
> > .data = &tscdata,
> > },
> > + {
> > + .compatible = "ti,am4372-magadc",
> > + .data = &magdata,
> > + },
> > { }
> > };
> > MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
> > @@ -363,6 +392,6 @@ static struct platform_driver ti_tscadc_driver = {
> >
> > module_platform_driver(ti_tscadc_driver);
> >
> > -MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
> > +MODULE_DESCRIPTION("TI touchscreen/magnetic reader/ADC MFD controller driver");
>
> Magnetic what? Tape, disk, stripe?
I guess my current knowledge of English tricked me as I thought
"magnetic reader" was clear enough for everybody, but I'll make the
commit logs and this module description clearer by specifying the
"stripe" keyword, sure.
>
> > MODULE_AUTHOR("Rachna Patil <rachna@xxxxxx>");
> > MODULE_LICENSE("GPL");
> > diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
> > index 467b3bec4335..9a412e6d764b 100644
> > --- a/include/linux/mfd/ti_am335x_tscadc.h
> > +++ b/include/linux/mfd/ti_am335x_tscadc.h
> > @@ -106,6 +106,11 @@
> > #define CNTRLREG_TSC_8WIRE CNTRLREG_TSC_AFE_CTRL(3)
> > #define CNTRLREG_TSC_ENB BIT(7)
> >
> > +/*Control registers bitfields for MAGADC IP */
> > +#define CNTRLREG_MAGADCENB BIT(0)
> > +#define CNTRLREG_MAG_PREAMP_PWRDOWN BIT(5)
> > +#define CNTRLREG_MAG_PREAMP_BYPASS BIT(6)
> > +
> > /* FIFO READ Register */
> > #define FIFOREAD_DATA_MASK GENMASK(11, 0)
> > #define FIFOREAD_CHNLID_MASK GENMASK(19, 16)
> > @@ -119,6 +124,7 @@
> > #define CHARGE_STEP 0x11
> >
> > #define TSC_ADC_CLK (3 * HZ_PER_MHZ)
> > +#define MAG_ADC_CLK (13 * HZ_PER_MHZ)
> > #define TOTAL_STEPS 16
> > #define TOTAL_CHANNELS 8
> > #define FIFO1_THRESHOLD 19
> > @@ -141,6 +147,7 @@
> >
> > struct ti_tscadc_data {
> > bool has_tsc;
> > + bool has_mag;
> > char *name_tscmag;
> > char *compat_tscmag;
> > char *name_adc;
>
Thanks,
Miquèl
