Re: [PATCH v2 04/10] iio: adc: at91-sama5d2_adc: convert to platform specific data structures
From: <hidden>
Date: 2021-08-31 11:50:07
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linux-devicetree, linux-iio, lkml
On 8/30/21 5:44 PM, Jonathan Cameron wrote:
On Mon, 30 Aug 2021 12:31:46 +0000 [off-list ref] wrote:quoted
On 8/24/21 2:54 PM, Eugen Hristev wrote:quoted
Convert the driver to platform specific structures. This means: - create a register layout struct that will hold offsets for registers - create a platform struct that will hold platform information (number of channels, indexes for different channels and pointer to layout struct) - convert specific macros that are platform dependent into platform variables This step is in fact a no-op, but allows the driver to be more flexible and for future enhancement including adding new platforms that are partly compatible with the current driver and differ slightly in register layout or capabilities for example. Signed-off-by: Eugen Hristev <redacted> --- drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------ 1 file changed, 247 insertions(+), 163 deletions(-)diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 9d71dcffcf93..8ede18b8d789 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c@@ -27,8 +27,9 @@ #include <linux/pinctrl/consumer.h> #include <linux/regulator/consumer.h> +struct at91_adc_reg_layout { /* Control Register */ -#define AT91_SAMA5D2_CR 0x00 + u16 CR; /* Software Reset */ #define AT91_SAMA5D2_CR_SWRST BIT(0) /* Start Conversion */@@ -39,7 +40,7 @@ #define AT91_SAMA5D2_CR_CMPRST BIT(4) /* Mode Register */ -#define AT91_SAMA5D2_MR 0x04 + u16 MR; /* Trigger Selection */ #define AT91_SAMA5D2_MR_TRGSEL(v) ((v) << 1) /* ADTRG */@@ -82,19 +83,19 @@ #define AT91_SAMA5D2_MR_USEQ BIT(31) /* Channel Sequence Register 1 */ -#define AT91_SAMA5D2_SEQR1 0x08 + u16 SEQR1; /* Channel Sequence Register 2 */ -#define AT91_SAMA5D2_SEQR2 0x0c + u16 SEQR2; /* Channel Enable Register */ -#define AT91_SAMA5D2_CHER 0x10 + u16 CHER; /* Channel Disable Register */ -#define AT91_SAMA5D2_CHDR 0x14 + u16 CHDR; /* Channel Status Register */ -#define AT91_SAMA5D2_CHSR 0x18 + u16 CHSR; /* Last Converted Data Register */ -#define AT91_SAMA5D2_LCDR 0x20 + u16 LCDR; /* Interrupt Enable Register */ -#define AT91_SAMA5D2_IER 0x24 + u16 IER; /* Interrupt Enable Register - TS X measurement ready */ #define AT91_SAMA5D2_IER_XRDY BIT(20) /* Interrupt Enable Register - TS Y measurement ready */@@ -109,22 +110,23 @@ #define AT91_SAMA5D2_IER_PEN BIT(29) /* Interrupt Enable Register - No pen detect */ #define AT91_SAMA5D2_IER_NOPEN BIT(30) + /* Interrupt Disable Register */ -#define AT91_SAMA5D2_IDR 0x28 + u16 IDR; /* Interrupt Mask Register */ -#define AT91_SAMA5D2_IMR 0x2c + u16 IMR; /* Interrupt Status Register */ -#define AT91_SAMA5D2_ISR 0x30 + u16 ISR; /* Interrupt Status Register - Pen touching sense status */ #define AT91_SAMA5D2_ISR_PENS BIT(31) /* Last Channel Trigger Mode Register */ -#define AT91_SAMA5D2_LCTMR 0x34 + u16 LCTMR; /* Last Channel Compare Window Register */ -#define AT91_SAMA5D2_LCCWR 0x38 + u16 LCCWR; /* Overrun Status Register */ -#define AT91_SAMA5D2_OVER 0x3c + u16 OVER; /* Extended Mode Register */ -#define AT91_SAMA5D2_EMR 0x40 + u16 EMR; /* Extended Mode Register - Oversampling rate */ #define AT91_SAMA5D2_EMR_OSR(V) ((V) << 16) #define AT91_SAMA5D2_EMR_OSR_MASK GENMASK(17, 16)@@ -134,22 +136,22 @@ /* Extended Mode Register - Averaging on single trigger event */ #define AT91_SAMA5D2_EMR_ASTE(V) ((V) << 20) + /* Compare Window Register */ -#define AT91_SAMA5D2_CWR 0x44 + u16 CWR; /* Channel Gain Register */ -#define AT91_SAMA5D2_CGR 0x48 - + u16 CGR; /* Channel Offset Register */ -#define AT91_SAMA5D2_COR 0x4c + u16 COR; #define AT91_SAMA5D2_COR_DIFF_OFFSET 16 /* Analog Control Register */ -#define AT91_SAMA5D2_ACR 0x94 + u16 ACR; /* Analog Control Register - Pen detect sensitivity mask */ #define AT91_SAMA5D2_ACR_PENDETSENS_MASK GENMASK(1, 0) /* Touchscreen Mode Register */ -#define AT91_SAMA5D2_TSMR 0xb0 + u16 TSMR; /* Touchscreen Mode Register - No touch mode */ #define AT91_SAMA5D2_TSMR_TSMODE_NONE 0 /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */@@ -178,13 +180,13 @@ #define AT91_SAMA5D2_TSMR_PENDET_ENA BIT(24) /* Touchscreen X Position Register */ -#define AT91_SAMA5D2_XPOSR 0xb4 + u16 XPOSR; /* Touchscreen Y Position Register */ -#define AT91_SAMA5D2_YPOSR 0xb8 + u16 YPOSR; /* Touchscreen Pressure Register */ -#define AT91_SAMA5D2_PRESSR 0xbc + u16 PRESSR; /* Trigger Register */ -#define AT91_SAMA5D2_TRGR 0xc0 + u16 TRGR; /* Mask for TRGMOD field of TRGR register */ #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0) /* No trigger, only software trigger can start conversions */@@ -203,30 +205,52 @@ #define AT91_SAMA5D2_TRGR_TRGPER(x) ((x) << 16) /* Correction Select Register */ -#define AT91_SAMA5D2_COSR 0xd0 + u16 COSR; /* Correction Value Register */ -#define AT91_SAMA5D2_CVR 0xd4 + u16 CVR; /* Channel Error Correction Register */ -#define AT91_SAMA5D2_CECR 0xd8 + u16 CECR; /* Write Protection Mode Register */ -#define AT91_SAMA5D2_WPMR 0xe4 + u16 WPMR; /* Write Protection Status Register */ -#define AT91_SAMA5D2_WPSR 0xe8 + u16 WPSR; /* Version Register */ -#define AT91_SAMA5D2_VERSION 0xfc - -#define AT91_SAMA5D2_HW_TRIG_CNT 3 -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12 -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6 - -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \ - AT91_SAMA5D2_DIFF_CHAN_CNT + 1) + u16 VERSION; +}; -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \ - AT91_SAMA5D2_DIFF_CHAN_CNT * 2)Hi Jonathan, While we are here, regarding the above line, I cannot tell why did I multiply by two the differential channel count. This makes some gaps in the number of channels when we put them all in the same table. I did not change this as it would break the ABI regarding the bindings for the touchscreen #adc-cells phandle references.Really? Xlate is based off scan_index, not these values I think...
I figured it out. We have 12 single channels [0..11] then 6 differential [12, 14, 16, 18, 20, 22] spaced by two, a timestamp [23], then we have the X channel index at 24, Y at 25 and pressure are 26. These are reflected in this file : https://elixir.bootlin.com/linux/latest/source/include/dt-bindings/iio/adc/at91-sama5d2_adc.h And the resistive touchscreen connects to the adc with these indexes. And I realised why we have the padding/spaces. It was the original design of the driver, in the line which I highlighted now below in the patch : (and I never changed this since working on this driver, because it was a break of the ABI in channel numbers ...)
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However, I am thinking if there was a reason for it or it was a slip when I initially wrote this.I've no idea :) I can't immediately see why we'd need the padding.quoted
Do you think there is any reason to change it and tighten the holes in the indexes list ?I don't think it matters. As far as I can tell they are used mostly (possibly entirely) for internal management and not exposed to any of the ABIs etc. Jonathanquoted
Eugenquoted
-#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1) -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1) -#define AT91_SAMA5D2_MAX_CHAN_IDX AT91_SAMA5D2_TOUCH_P_CHAN_IDX +static const struct at91_adc_reg_layout sama5d2_layout = { + .CR = 0x00, + .MR = 0x04, + .SEQR1 = 0x08, + .SEQR2 = 0x0c, + .CHER = 0x10, + .CHDR = 0x14, + .CHSR = 0x18, + .LCDR = 0x20, + .IER = 0x24, + .IDR = 0x28, + .IMR = 0x2c, + .ISR = 0x30, + .LCTMR = 0x34, + .LCCWR = 0x38, + .OVER = 0x3c, + .EMR = 0x40, + .CWR = 0x44, + .CGR = 0x48, + .COR = 0x4c, + .ACR = 0x94, + .TSMR = 0xb0, + .XPOSR = 0xb4, + .YPOSR = 0xb8, + .PRESSR = 0xbc, + .TRGR = 0xc0, + .COSR = 0xd0, + .CVR = 0xd4, + .CECR = 0xd8, + .WPMR = 0xe4, + .WPSR = 0xe8, + .VERSION = 0xfc, +}; #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */ #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US 200@@ -235,18 +259,6 @@ #define AT91_SAMA5D2_MAX_POS_BITS 12 -/* - * Maximum number of bytes to hold conversion from all channels - * without the timestamp. - */ -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \ - AT91_SAMA5D2_DIFF_CHAN_CNT) * 2) - -/* This total must also include the timestamp */ -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8) - -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2) - #define AT91_HWFIFO_MAX_SIZE_STR "128" #define AT91_HWFIFO_MAX_SIZE 128@@ -255,12 +267,12 @@ #define AT91_OSR_4SAMPLES 4 #define AT91_OSR_16SAMPLES 16 -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \ +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr) \ { \ .type = IIO_VOLTAGE, \ .channel = num, \ .address = addr, \ - .scan_index = num, \ + .scan_index = index, \ .scan_type = { \ .sign = 'u', \ .realbits = 14, \@@ -274,14 +286,14 @@ .indexed = 1, \ } -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr) \ +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr) \ { \ .type = IIO_VOLTAGE, \ .differential = 1, \ .channel = num, \ .channel2 = num2, \ .address = addr, \ - .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT, \
Here it is: we always added num to the single channel count, but num goes incrementally in steps of two : 0, 2, 4, 6, 8, 10
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+ .scan_index = index, \ .scan_type = { \ .sign = 's', \ .realbits = 14, \@@ -328,13 +340,48 @@ .datasheet_name = name, \ } -#define at91_adc_readl(st, reg) readl_relaxed(st->base + reg) -#define at91_adc_writel(st, reg, val) writel_relaxed(val, st->base + reg) +#define at91_adc_readl(st, reg) \ + readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg) +#define at91_adc_read_chan(st, reg) \ + readl_relaxed((st)->base + reg) +#define at91_adc_writel(st, reg, val) \ + writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg) + +/** + * struct at91_adc_platform - at91-sama5d2 platform information struct + * @layout: pointer to the reg layout struct + * @adc_channels: pointer to an array of channels for registering in + * the iio subsystem + * @nr_channels: number of physical channels available + * @touch_chan_x: index of the touchscreen X channel + * @touch_chan_y: index of the touchscreen Y channel + * @touch_chan_p: index of the touchscreen P channel + * @max_channels: number of total channels + * @hw_trig_cnt: number of possible hardware triggers + */ +struct at91_adc_platform { + const struct at91_adc_reg_layout *layout; + const struct iio_chan_spec (*adc_channels)[]; + unsigned int nr_channels; + unsigned int touch_chan_x; + unsigned int touch_chan_y; + unsigned int touch_chan_p; + unsigned int max_channels; + unsigned int hw_trig_cnt; +}; +/** + * struct at91_adc_soc_info - at91-sama5d2 soc information struct + * @startup_time: device startup time + * @min_sample_rate: minimum sample rate in Hz + * @max_sample_rate: maximum sample rate in Hz + * @platform: pointer to the platform structure + */ struct at91_adc_soc_info { unsigned startup_time; unsigned min_sample_rate; unsigned max_sample_rate; + const struct at91_adc_platform *platform; }; struct at91_adc_trigger {@@ -382,6 +429,15 @@ struct at91_adc_touch { struct work_struct workq; }; +/* + * Buffer size requirements: + * No channels * bytes_per_channel(2) + timestamp bytes (8) + * Divided by 2 because we need half words. + * We assume 32 channels for now, has to be increased if needed. + * Nobody minds a buffer being too big. + */ +#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2) + struct at91_adc_state { void __iomem *base; int irq;@@ -437,29 +493,49 @@ static const struct at91_adc_trigger at91_adc_trigger_list[] = { }, }; -static const struct iio_chan_spec at91_adc_channels[] = { - AT91_SAMA5D2_CHAN_SINGLE(0, 0x50), - AT91_SAMA5D2_CHAN_SINGLE(1, 0x54), - AT91_SAMA5D2_CHAN_SINGLE(2, 0x58), - AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c), - AT91_SAMA5D2_CHAN_SINGLE(4, 0x60), - AT91_SAMA5D2_CHAN_SINGLE(5, 0x64), - AT91_SAMA5D2_CHAN_SINGLE(6, 0x68), - AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c), - AT91_SAMA5D2_CHAN_SINGLE(8, 0x70), - AT91_SAMA5D2_CHAN_SINGLE(9, 0x74), - AT91_SAMA5D2_CHAN_SINGLE(10, 0x78), - AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c), - AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50), - AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58), - AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60), - AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68), - AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70), - AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
you can see it here,
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- IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX), - AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X), - AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y), - AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"), +static const struct iio_chan_spec at91_sama5d2_adc_channels[] = { + AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50), + AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54), + AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58), + AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c), + AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60), + AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64), + AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68), + AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c), + AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70), + AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74), + AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78), + AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c), + AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50), + AT91_SAMA5D2_CHAN_DIFF(13, 2, 3, 0x58), + AT91_SAMA5D2_CHAN_DIFF(14, 4, 5, 0x60), + AT91_SAMA5D2_CHAN_DIFF(15, 6, 7, 0x68), + AT91_SAMA5D2_CHAN_DIFF(16, 8, 9, 0x70), + AT91_SAMA5D2_CHAN_DIFF(17, 10, 11, 0x78), + IIO_CHAN_SOFT_TIMESTAMP(18), + AT91_SAMA5D2_CHAN_TOUCH(19, "x", IIO_MOD_X), + AT91_SAMA5D2_CHAN_TOUCH(20, "y", IIO_MOD_Y), + AT91_SAMA5D2_CHAN_PRESSURE(21, "pressure"),
And I have to come up with a new version of the patch to fix this. It should be like this: >>> + AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c), >>> + AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50), >>> + AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58), >>> + AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60), >>> + AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68), >>> + AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70), >>> + AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78), >>> + IIO_CHAN_SOFT_TIMESTAMP(23), >>> + AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X), >>> + AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y), >>> + AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"), Sorry about this. Do you want me to resend the whole series together with the fixes found by robots ? I can redo the series, retest it, and send it tomorrow as a v3. Thanks, Eugen
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+}; +
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