Thread (88 messages) 88 messages, 4 authors, 2021-09-05
STALE1726d
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[PATCH 28/40] mfd: ti_am335x_tscadc: Add ADC1/magnetic reader support

From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: 2021-08-25 15:34:58
Also in: linux-clk, linux-devicetree, linux-iio, linux-omap
Subsystem: multifunction devices (mfd), the rest · Maintainers: Lee Jones, Linus Torvalds

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.

Co-developed-by: Jason Reeder <redacted>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jason Reeder <redacted>
---
 drivers/mfd/ti_am335x_tscadc.c       | 43 ++++++++++++++++++++++------
 include/linux/mfd/ti_am335x_tscadc.h |  9 +++++-
 2 files changed, 43 insertions(+), 9 deletions(-)
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 1a30610dc65f..f4f6b9db4d2a 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -122,9 +122,9 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 	const __be32 *cur;
 	struct clk *clk;
 	u32 val;
-	bool use_tsc = false;
+	bool use_tsc = false, use_mag = false;
 	int tscmag_wires = 0, adc_channels = 0, readouts = 0, cell_idx = 0;
-	int total_channels, err;
+	int mag_tracks = 0, total_channels, err;
 
 	/* Allocate memory for device */
 	tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL);
@@ -146,6 +146,12 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 		of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
 		if (tscmag_wires)
 			use_tsc = true;
+	} else {
+		node = of_get_child_by_name(pdev->dev.of_node, "mag");
+		of_property_read_u32(node, "ti,tracks", &mag_tracks);
+		tscmag_wires = mag_tracks * 2;
+		if (tscmag_wires)
+			use_mag = true;
 	}
 
 	node = of_get_child_by_name(pdev->dev.of_node, "adc");
@@ -206,8 +212,9 @@ 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);
@@ -231,7 +238,9 @@ 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);
@@ -241,7 +250,7 @@ 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;
@@ -329,6 +338,7 @@ 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",
@@ -336,8 +346,25 @@ 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,
+	.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", },
+	{
+		.compatible = "ti,am3359-tscadc",
+		.data = &tscdata,
+	},
+	{
+		.compatible = "ti,am4372-magadc",
+		.data = &magdata,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
@@ -355,6 +382,6 @@ 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");
 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
 MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 082b2af94263..31b22ec567e7 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -129,6 +129,11 @@
 #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 (0xfff << 0)
 #define FIFOREAD_CHNLID_MASK (0xf << 16)
@@ -141,7 +146,8 @@
 #define SEQ_STATUS BIT(5)
 #define CHARGE_STEP		0x11
 
-#define TSC_ADC_CLK		3000000
+#define TSC_ADC_CLK		3000000 /* 3 MHz */
+#define MAG_ADC_CLK		13000000 /* 13 MHz */
 #define TOTAL_STEPS		16
 #define TOTAL_CHANNELS		8
 #define FIFO1_THRESHOLD		19
@@ -164,6 +170,7 @@
 
 struct ti_tscadc_data {
 	bool has_tsc;
+	bool has_mag;
 	char *name_tscmag;
 	char *compat_tscmag;
 	char *name_adc;
-- 
2.27.0
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