forked from mirrors/linux
		
	iio: Add driver for Broadcom iproc-static-adc
This patch adds basic driver implementation for Broadcom's static adc controller used in iProc SoC's family. Signed-off-by: Raveendra Padasalagi <raveendra.padasalagi@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Reviewed-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
		
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					 3 changed files with 657 additions and 0 deletions
				
			
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			@ -153,6 +153,18 @@ config AXP288_ADC
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	  To compile this driver as a module, choose M here: the module will be
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	  called axp288_adc.
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config BCM_IPROC_ADC
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	tristate "Broadcom IPROC ADC driver"
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	depends on ARCH_BCM_IPROC || COMPILE_TEST
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	depends on MFD_SYSCON
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	default ARCH_BCM_CYGNUS
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	help
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	  Say Y here if you want to add support for the Broadcom static
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	  ADC driver.
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	  Broadcom iProc ADC driver. Broadcom iProc ADC controller has 8
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	  channels. The driver allows the user to read voltage values.
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config BERLIN2_ADC
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	tristate "Marvell Berlin2 ADC driver"
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	depends on ARCH_BERLIN
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			@ -16,6 +16,7 @@ obj-$(CONFIG_AD799X) += ad799x.o
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obj-$(CONFIG_AT91_ADC) += at91_adc.o
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obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o
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obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
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obj-$(CONFIG_BCM_IPROC_ADC) += bcm_iproc_adc.o
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obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
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obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
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obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
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										644
									
								
								drivers/iio/adc/bcm_iproc_adc.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										644
									
								
								drivers/iio/adc/bcm_iproc_adc.c
									
									
									
									
									
										Normal file
									
								
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			@ -0,0 +1,644 @@
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/*
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 * Copyright 2016 Broadcom
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License, version 2, as
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 * published by the Free Software Foundation (the "GPL").
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 *
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 * This program is distributed in the hope that it will be useful, but
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 * WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * General Public License version 2 (GPLv2) for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * version 2 (GPLv2) along with this source code.
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 */
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/mfd/syscon.h>
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#include <linux/regmap.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/iio/iio.h>
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/* Below Register's are common to IPROC ADC and Touchscreen IP */
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#define IPROC_REGCTL1			0x00
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#define IPROC_REGCTL2			0x04
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#define IPROC_INTERRUPT_THRES		0x08
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#define IPROC_INTERRUPT_MASK		0x0c
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#define IPROC_INTERRUPT_STATUS		0x10
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#define IPROC_ANALOG_CONTROL		0x1c
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#define IPROC_CONTROLLER_STATUS		0x14
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#define IPROC_AUX_DATA			0x20
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#define IPROC_SOFT_BYPASS_CONTROL	0x38
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#define IPROC_SOFT_BYPASS_DATA		0x3C
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/* IPROC ADC Channel register offsets */
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#define IPROC_ADC_CHANNEL_REGCTL1		0x800
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#define IPROC_ADC_CHANNEL_REGCTL2		0x804
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#define IPROC_ADC_CHANNEL_STATUS		0x808
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#define IPROC_ADC_CHANNEL_INTERRUPT_STATUS	0x80c
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#define IPROC_ADC_CHANNEL_INTERRUPT_MASK	0x810
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#define IPROC_ADC_CHANNEL_DATA			0x814
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#define IPROC_ADC_CHANNEL_OFFSET		0x20
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/* Bit definitions for IPROC_REGCTL2 */
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#define IPROC_ADC_AUXIN_SCAN_ENA	BIT(0)
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#define IPROC_ADC_PWR_LDO		BIT(5)
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#define IPROC_ADC_PWR_ADC		BIT(4)
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#define IPROC_ADC_PWR_BG		BIT(3)
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#define IPROC_ADC_CONTROLLER_EN		BIT(17)
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/* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
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#define IPROC_ADC_AUXDATA_RDY_INTR	BIT(3)
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#define IPROC_ADC_INTR			9
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#define IPROC_ADC_INTR_MASK		(0xFF << IPROC_ADC_INTR)
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/* Bit definitions for IPROC_ANALOG_CONTROL */
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#define IPROC_ADC_CHANNEL_SEL		11
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#define IPROC_ADC_CHANNEL_SEL_MASK	(0x7 << IPROC_ADC_CHANNEL_SEL)
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/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
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#define IPROC_ADC_CHANNEL_ROUNDS	0x2
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#define IPROC_ADC_CHANNEL_ROUNDS_MASK	(0x3F << IPROC_ADC_CHANNEL_ROUNDS)
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#define IPROC_ADC_CHANNEL_MODE		0x1
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#define IPROC_ADC_CHANNEL_MODE_MASK	(0x1 << IPROC_ADC_CHANNEL_MODE)
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#define IPROC_ADC_CHANNEL_MODE_TDM	0x1
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#define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
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#define IPROC_ADC_CHANNEL_ENABLE	0x0
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#define IPROC_ADC_CHANNEL_ENABLE_MASK	0x1
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/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
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#define IPROC_ADC_CHANNEL_WATERMARK	0x0
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#define IPROC_ADC_CHANNEL_WATERMARK_MASK \
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		(0x3F << IPROC_ADC_CHANNEL_WATERMARK)
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#define IPROC_ADC_WATER_MARK_LEVEL	0x1
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/* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
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#define IPROC_ADC_CHANNEL_DATA_LOST		0x0
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#define IPROC_ADC_CHANNEL_DATA_LOST_MASK	\
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		(0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
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#define IPROC_ADC_CHANNEL_VALID_ENTERIES	0x1
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#define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK	\
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		(0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
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#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES	0x9
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#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK	\
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		(0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)
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/* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
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#define IPROC_ADC_CHANNEL_WTRMRK_INTR			0x0
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#define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK		\
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		(0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
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#define IPROC_ADC_CHANNEL_FULL_INTR			0x1
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#define IPROC_ADC_CHANNEL_FULL_INTR_MASK		\
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		(0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
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#define IPROC_ADC_CHANNEL_EMPTY_INTR			0x2
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#define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK		\
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		(0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)
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#define IPROC_ADC_WATER_MARK_INTR_ENABLE		0x1
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/* Number of time to retry a set of the interrupt mask reg */
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#define IPROC_ADC_INTMASK_RETRY_ATTEMPTS		10
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#define IPROC_ADC_READ_TIMEOUT        (HZ*2)
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#define iproc_adc_dbg_reg(dev, priv, reg) \
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do { \
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	u32 val; \
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	regmap_read(priv->regmap, reg, &val); \
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	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
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} while (0)
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struct iproc_adc_priv {
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	struct regmap *regmap;
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	struct clk *adc_clk;
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	struct mutex mutex;
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	int  irqno;
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	int chan_val;
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	int chan_id;
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	struct completion completion;
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};
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static void iproc_adc_reg_dump(struct iio_dev *indio_dev)
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{
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	struct device *dev = &indio_dev->dev;
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	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL1);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL2);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_THRES);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_MASK);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_STATUS);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_CONTROLLER_STATUS);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_ANALOG_CONTROL);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_AUX_DATA);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_CONTROL);
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	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_DATA);
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}
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static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data)
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{
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	u32 channel_intr_status;
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	u32 intr_status;
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	u32 intr_mask;
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	struct iio_dev *indio_dev = data;
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	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
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	/*
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	 * This interrupt is shared with the touchscreen driver.
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	 * Make sure this interrupt is intended for us.
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	 * Handle only ADC channel specific interrupts.
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	 */
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	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
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	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &intr_mask);
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	intr_status = intr_status & intr_mask;
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	channel_intr_status = (intr_status & IPROC_ADC_INTR_MASK) >>
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				IPROC_ADC_INTR;
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	if (channel_intr_status)
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		return IRQ_WAKE_THREAD;
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	return IRQ_NONE;
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}
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static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data)
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{
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	irqreturn_t retval = IRQ_NONE;
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	struct iproc_adc_priv *adc_priv;
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	struct iio_dev *indio_dev = data;
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	unsigned int valid_entries;
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	u32 intr_status;
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	u32 intr_channels;
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	u32 channel_status;
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	u32 ch_intr_status;
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	adc_priv = iio_priv(indio_dev);
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	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
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	dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_thread(),INTRPT_STS:%x\n",
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			intr_status);
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	intr_channels = (intr_status & IPROC_ADC_INTR_MASK) >> IPROC_ADC_INTR;
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	if (intr_channels) {
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		regmap_read(adc_priv->regmap,
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			    IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
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			    IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
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			    &ch_intr_status);
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		if (ch_intr_status & IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK) {
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			regmap_read(adc_priv->regmap,
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					IPROC_ADC_CHANNEL_STATUS +
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					IPROC_ADC_CHANNEL_OFFSET *
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					adc_priv->chan_id,
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					&channel_status);
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			valid_entries = ((channel_status &
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				IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK) >>
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				IPROC_ADC_CHANNEL_VALID_ENTERIES);
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			if (valid_entries >= 1) {
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				regmap_read(adc_priv->regmap,
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					IPROC_ADC_CHANNEL_DATA +
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					IPROC_ADC_CHANNEL_OFFSET *
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					adc_priv->chan_id,
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					&adc_priv->chan_val);
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				complete(&adc_priv->completion);
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			} else {
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				dev_err(&indio_dev->dev,
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					"No data rcvd on channel %d\n",
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					adc_priv->chan_id);
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			}
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			regmap_write(adc_priv->regmap,
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					IPROC_ADC_CHANNEL_INTERRUPT_MASK +
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					IPROC_ADC_CHANNEL_OFFSET *
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					adc_priv->chan_id,
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					(ch_intr_status &
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					~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK)));
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		}
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		regmap_write(adc_priv->regmap,
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				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
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				IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
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				ch_intr_status);
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		regmap_write(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
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				intr_channels);
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		retval = IRQ_HANDLED;
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	}
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	return retval;
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}
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static int iproc_adc_do_read(struct iio_dev *indio_dev,
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			   int channel,
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			   u16 *p_adc_data)
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{
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	int read_len = 0;
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	u32 val;
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	u32 mask;
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	u32 val_check;
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	int failed_cnt = 0;
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	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
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	mutex_lock(&adc_priv->mutex);
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	/*
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	 * After a read is complete the ADC interrupts will be disabled so
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	 * we can assume this section of code is safe from interrupts.
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	 */
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	adc_priv->chan_val = -1;
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	adc_priv->chan_id = channel;
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	reinit_completion(&adc_priv->completion);
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	/* Clear any pending interrupt */
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	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
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			IPROC_ADC_INTR_MASK | IPROC_ADC_AUXDATA_RDY_INTR,
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			((0x0 << channel) << IPROC_ADC_INTR) |
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			IPROC_ADC_AUXDATA_RDY_INTR);
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	/* Configure channel for snapshot mode and enable  */
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	val = (BIT(IPROC_ADC_CHANNEL_ROUNDS) |
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		(IPROC_ADC_CHANNEL_MODE_SNAPSHOT << IPROC_ADC_CHANNEL_MODE) |
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		(0x1 << IPROC_ADC_CHANNEL_ENABLE));
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	mask = IPROC_ADC_CHANNEL_ROUNDS_MASK | IPROC_ADC_CHANNEL_MODE_MASK |
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		IPROC_ADC_CHANNEL_ENABLE_MASK;
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	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL1 +
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				IPROC_ADC_CHANNEL_OFFSET * channel),
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				mask, val);
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	/* Set the Watermark for a channel */
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	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL2 +
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					IPROC_ADC_CHANNEL_OFFSET * channel),
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					IPROC_ADC_CHANNEL_WATERMARK_MASK,
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					0x1);
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	/* Enable water mark interrupt */
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	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_INTERRUPT_MASK +
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					IPROC_ADC_CHANNEL_OFFSET *
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					channel),
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					IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK,
 | 
			
		||||
					IPROC_ADC_WATER_MARK_INTR_ENABLE);
 | 
			
		||||
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val);
 | 
			
		||||
 | 
			
		||||
	/* Enable ADC interrupt for a channel */
 | 
			
		||||
	val |= (BIT(channel) << IPROC_ADC_INTR);
 | 
			
		||||
	regmap_write(adc_priv->regmap, IPROC_INTERRUPT_MASK, val);
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * There seems to be a very rare issue where writing to this register
 | 
			
		||||
	 * does not take effect.  To work around the issue we will try multiple
 | 
			
		||||
	 * writes.  In total we will spend about 10*10 = 100 us attempting this.
 | 
			
		||||
	 * Testing has shown that this may loop a few time, but we have never
 | 
			
		||||
	 * hit the full count.
 | 
			
		||||
	 */
 | 
			
		||||
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
 | 
			
		||||
	while (val_check != val) {
 | 
			
		||||
		failed_cnt++;
 | 
			
		||||
 | 
			
		||||
		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS)
 | 
			
		||||
			break;
 | 
			
		||||
 | 
			
		||||
		udelay(10);
 | 
			
		||||
		regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
 | 
			
		||||
				IPROC_ADC_INTR_MASK,
 | 
			
		||||
				((0x1 << channel) <<
 | 
			
		||||
				IPROC_ADC_INTR));
 | 
			
		||||
 | 
			
		||||
		regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (failed_cnt) {
 | 
			
		||||
		dev_dbg(&indio_dev->dev,
 | 
			
		||||
			"IntMask failed (%d times)", failed_cnt);
 | 
			
		||||
		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS) {
 | 
			
		||||
			dev_err(&indio_dev->dev,
 | 
			
		||||
				"IntMask set failed. Read will likely fail.");
 | 
			
		||||
			read_len = -EIO;
 | 
			
		||||
			goto adc_err;
 | 
			
		||||
		};
 | 
			
		||||
	}
 | 
			
		||||
	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
 | 
			
		||||
 | 
			
		||||
	if (wait_for_completion_timeout(&adc_priv->completion,
 | 
			
		||||
		IPROC_ADC_READ_TIMEOUT) > 0) {
 | 
			
		||||
 | 
			
		||||
		/* Only the lower 16 bits are relevant */
 | 
			
		||||
		*p_adc_data = adc_priv->chan_val & 0xFFFF;
 | 
			
		||||
		read_len = sizeof(*p_adc_data);
 | 
			
		||||
 | 
			
		||||
	} else {
 | 
			
		||||
		/*
 | 
			
		||||
		 * We never got the interrupt, something went wrong.
 | 
			
		||||
		 * Perhaps the interrupt may still be coming, we do not want
 | 
			
		||||
		 * that now.  Lets disable the ADC interrupt, and clear the
 | 
			
		||||
		 * status to put it back in to normal state.
 | 
			
		||||
		 */
 | 
			
		||||
		read_len = -ETIMEDOUT;
 | 
			
		||||
		goto adc_err;
 | 
			
		||||
	}
 | 
			
		||||
	mutex_unlock(&adc_priv->mutex);
 | 
			
		||||
 | 
			
		||||
	return read_len;
 | 
			
		||||
 | 
			
		||||
adc_err:
 | 
			
		||||
	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
 | 
			
		||||
			   IPROC_ADC_INTR_MASK,
 | 
			
		||||
			   ((0x0 << channel) << IPROC_ADC_INTR));
 | 
			
		||||
 | 
			
		||||
	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
 | 
			
		||||
			   IPROC_ADC_INTR_MASK,
 | 
			
		||||
			   ((0x0 << channel) << IPROC_ADC_INTR));
 | 
			
		||||
 | 
			
		||||
	dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n");
 | 
			
		||||
	iproc_adc_reg_dump(indio_dev);
 | 
			
		||||
	mutex_unlock(&adc_priv->mutex);
 | 
			
		||||
 | 
			
		||||
	return read_len;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int iproc_adc_enable(struct iio_dev *indio_dev)
 | 
			
		||||
{
 | 
			
		||||
	u32 val;
 | 
			
		||||
	u32 channel_id;
 | 
			
		||||
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	/* Set i_amux = 3b'000, select channel 0 */
 | 
			
		||||
	ret = regmap_update_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
 | 
			
		||||
				IPROC_ADC_CHANNEL_SEL_MASK, 0);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to write IPROC_ANALOG_CONTROL %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
	adc_priv->chan_val = -1;
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * PWR up LDO, ADC, and Band Gap (0 to enable)
 | 
			
		||||
	 * Also enable ADC controller (set high)
 | 
			
		||||
	 */
 | 
			
		||||
	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to read IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	val &= ~(IPROC_ADC_PWR_LDO | IPROC_ADC_PWR_ADC | IPROC_ADC_PWR_BG);
 | 
			
		||||
 | 
			
		||||
	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to write IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to read IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	val |= IPROC_ADC_CONTROLLER_EN;
 | 
			
		||||
	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to write IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	for (channel_id = 0; channel_id < indio_dev->num_channels;
 | 
			
		||||
		channel_id++) {
 | 
			
		||||
		ret = regmap_write(adc_priv->regmap,
 | 
			
		||||
				IPROC_ADC_CHANNEL_INTERRUPT_MASK +
 | 
			
		||||
				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
 | 
			
		||||
		if (ret) {
 | 
			
		||||
			dev_err(&indio_dev->dev,
 | 
			
		||||
			    "failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
 | 
			
		||||
			    ret);
 | 
			
		||||
			return ret;
 | 
			
		||||
		}
 | 
			
		||||
 | 
			
		||||
		ret = regmap_write(adc_priv->regmap,
 | 
			
		||||
				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
 | 
			
		||||
				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
 | 
			
		||||
		if (ret) {
 | 
			
		||||
			dev_err(&indio_dev->dev,
 | 
			
		||||
			    "failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
 | 
			
		||||
			    ret);
 | 
			
		||||
			return ret;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static void iproc_adc_disable(struct iio_dev *indio_dev)
 | 
			
		||||
{
 | 
			
		||||
	u32 val;
 | 
			
		||||
	int ret;
 | 
			
		||||
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
 | 
			
		||||
 | 
			
		||||
	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to read IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	val &= ~IPROC_ADC_CONTROLLER_EN;
 | 
			
		||||
	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&indio_dev->dev,
 | 
			
		||||
			"failed to write IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return;
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int iproc_adc_read_raw(struct iio_dev *indio_dev,
 | 
			
		||||
			  struct iio_chan_spec const *chan,
 | 
			
		||||
			  int *val,
 | 
			
		||||
			  int *val2,
 | 
			
		||||
			  long mask)
 | 
			
		||||
{
 | 
			
		||||
	u16 adc_data;
 | 
			
		||||
	int err;
 | 
			
		||||
 | 
			
		||||
	switch (mask) {
 | 
			
		||||
	case IIO_CHAN_INFO_RAW:
 | 
			
		||||
		err =  iproc_adc_do_read(indio_dev, chan->channel, &adc_data);
 | 
			
		||||
		if (err < 0)
 | 
			
		||||
			return err;
 | 
			
		||||
		*val = adc_data;
 | 
			
		||||
		return IIO_VAL_INT;
 | 
			
		||||
	case IIO_CHAN_INFO_SCALE:
 | 
			
		||||
		switch (chan->type) {
 | 
			
		||||
		case IIO_VOLTAGE:
 | 
			
		||||
			*val = 1800;
 | 
			
		||||
			*val2 = 10;
 | 
			
		||||
			return IIO_VAL_FRACTIONAL_LOG2;
 | 
			
		||||
		default:
 | 
			
		||||
			return -EINVAL;
 | 
			
		||||
		}
 | 
			
		||||
	default:
 | 
			
		||||
		return -EINVAL;
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static const struct iio_info iproc_adc_iio_info = {
 | 
			
		||||
	.read_raw = &iproc_adc_read_raw,
 | 
			
		||||
	.driver_module = THIS_MODULE,
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
#define IPROC_ADC_CHANNEL(_index, _id) {                \
 | 
			
		||||
	.type = IIO_VOLTAGE,                            \
 | 
			
		||||
	.indexed = 1,                                   \
 | 
			
		||||
	.channel = _index,                              \
 | 
			
		||||
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
 | 
			
		||||
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 | 
			
		||||
	.datasheet_name = _id,                          \
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static const struct iio_chan_spec iproc_adc_iio_channels[] = {
 | 
			
		||||
	IPROC_ADC_CHANNEL(0, "adc0"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(1, "adc1"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(2, "adc2"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(3, "adc3"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(4, "adc4"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(5, "adc5"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(6, "adc6"),
 | 
			
		||||
	IPROC_ADC_CHANNEL(7, "adc7"),
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static int iproc_adc_probe(struct platform_device *pdev)
 | 
			
		||||
{
 | 
			
		||||
	struct iproc_adc_priv *adc_priv;
 | 
			
		||||
	struct iio_dev *indio_dev = NULL;
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	indio_dev = devm_iio_device_alloc(&pdev->dev,
 | 
			
		||||
					sizeof(*adc_priv));
 | 
			
		||||
	if (!indio_dev) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to allocate iio device\n");
 | 
			
		||||
		return -ENOMEM;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	adc_priv = iio_priv(indio_dev);
 | 
			
		||||
	platform_set_drvdata(pdev, indio_dev);
 | 
			
		||||
 | 
			
		||||
	mutex_init(&adc_priv->mutex);
 | 
			
		||||
 | 
			
		||||
	init_completion(&adc_priv->completion);
 | 
			
		||||
 | 
			
		||||
	adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 | 
			
		||||
			   "adc-syscon");
 | 
			
		||||
	if (IS_ERR(adc_priv->regmap)) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to get handle for tsc syscon\n");
 | 
			
		||||
		ret = PTR_ERR(adc_priv->regmap);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
 | 
			
		||||
	if (IS_ERR(adc_priv->adc_clk)) {
 | 
			
		||||
		dev_err(&pdev->dev,
 | 
			
		||||
			"failed getting clock tsc_clk\n");
 | 
			
		||||
		ret = PTR_ERR(adc_priv->adc_clk);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	adc_priv->irqno = platform_get_irq(pdev, 0);
 | 
			
		||||
	if (adc_priv->irqno <= 0) {
 | 
			
		||||
		dev_err(&pdev->dev, "platform_get_irq failed\n");
 | 
			
		||||
		ret = -ENODEV;
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	ret = regmap_update_bits(adc_priv->regmap, IPROC_REGCTL2,
 | 
			
		||||
				IPROC_ADC_AUXIN_SCAN_ENA, 0);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to write IPROC_REGCTL2 %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno,
 | 
			
		||||
				iproc_adc_interrupt_thread,
 | 
			
		||||
				iproc_adc_interrupt_handler,
 | 
			
		||||
				IRQF_SHARED, "iproc-adc", indio_dev);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "request_irq error %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	ret = clk_prepare_enable(adc_priv->adc_clk);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev,
 | 
			
		||||
			"clk_prepare_enable failed %d\n", ret);
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	ret = iproc_adc_enable(indio_dev);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "failed to enable adc %d\n", ret);
 | 
			
		||||
		goto err_adc_enable;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	indio_dev->name = "iproc-static-adc";
 | 
			
		||||
	indio_dev->dev.parent = &pdev->dev;
 | 
			
		||||
	indio_dev->dev.of_node = pdev->dev.of_node;
 | 
			
		||||
	indio_dev->info = &iproc_adc_iio_info;
 | 
			
		||||
	indio_dev->modes = INDIO_DIRECT_MODE;
 | 
			
		||||
	indio_dev->channels = iproc_adc_iio_channels;
 | 
			
		||||
	indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels);
 | 
			
		||||
 | 
			
		||||
	ret = iio_device_register(indio_dev);
 | 
			
		||||
	if (ret) {
 | 
			
		||||
		dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret);
 | 
			
		||||
		goto err_clk;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
 | 
			
		||||
err_clk:
 | 
			
		||||
	iproc_adc_disable(indio_dev);
 | 
			
		||||
err_adc_enable:
 | 
			
		||||
	clk_disable_unprepare(adc_priv->adc_clk);
 | 
			
		||||
 | 
			
		||||
	return ret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int iproc_adc_remove(struct platform_device *pdev)
 | 
			
		||||
{
 | 
			
		||||
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 | 
			
		||||
	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
 | 
			
		||||
 | 
			
		||||
	iio_device_unregister(indio_dev);
 | 
			
		||||
	iproc_adc_disable(indio_dev);
 | 
			
		||||
	clk_disable_unprepare(adc_priv->adc_clk);
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static const struct of_device_id iproc_adc_of_match[] = {
 | 
			
		||||
	{.compatible = "brcm,iproc-static-adc", },
 | 
			
		||||
	{ },
 | 
			
		||||
};
 | 
			
		||||
MODULE_DEVICE_TABLE(of, iproc_adc_of_match);
 | 
			
		||||
 | 
			
		||||
static struct platform_driver iproc_adc_driver = {
 | 
			
		||||
	.probe  = iproc_adc_probe,
 | 
			
		||||
	.remove	= iproc_adc_remove,
 | 
			
		||||
	.driver	= {
 | 
			
		||||
		.name	= "iproc-static-adc",
 | 
			
		||||
		.of_match_table = of_match_ptr(iproc_adc_of_match),
 | 
			
		||||
	},
 | 
			
		||||
};
 | 
			
		||||
module_platform_driver(iproc_adc_driver);
 | 
			
		||||
 | 
			
		||||
MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
 | 
			
		||||
MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
 | 
			
		||||
MODULE_LICENSE("GPL v2");
 | 
			
		||||
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		Reference in a new issue