Re: [PATCH v14 1/5] mfd: mxs-lradc: Add support for mxs-lradc MFD
From: Stefan Wahren <hidden>
Date: 2017-03-01 20:15:03
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linux-iio, lkml
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Ksenija Stanojevic [off-list ref] hat am 1. März 2017 um 19:02 geschrieben: Add core files for low resolution analog-to-digital converter (mxs-lradc) MFD driver. Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com> Acked-by: Lee Jones <redacted> --- Changes in v14: - none Changes in v13: - none Changes in v12: - use BIT macro Changes in v11: - create static struct mfd_cells - don't set platform data in mfd cells, set driver data instead - remove mxs_lradc_reg_* functions, use writel function instead Changes in v10: - fetch base address from DT - add a NULL check for of_match_device Changes in v9: - improve commit message. Changes in v8: - rebase onto 4.9-rc1 Changes in v7: - define macros ADC_CELL and TSC_CELL - remove one cell and dynamically set them in the switch() - fail in the touchscreen driver instead of mfd driver if hardware doesn't contain a touchscreen Changes in v6: - update copyright - add kernel-doc header for struct mxs-lradc - add error message - change EINVAL to ENODEV - use PLATFORM_DEVID_NONE instead -1 - cosmetic fixes Changes in v5: - use DEFINE_RES_MEM - don't pass ioreammaped adress to platform cells - move comment outside of struct mxs_lradc - change type of argument in mxs_lradc_reg_set, mxs_lradc_reg_clear, mxs_lradc_reg_wrt (struct mxs_lradc * -> void __iomem *) Changes in v4: - update copyright - use DEFINE_RES_IRQ_NAMED - remove mxs_lradc_add_device function - use struct mfd_cell in static form - improve spacing - remove unnecessary comment - remove platform_get_irq - remove touch_ret and use ret instead - rename use_touchscreen to touchscreen_wire - use goto statements - remove irq[13], irq_count and irq_name from struct mxs_lradc - remove all defines from inside the struct definition Changes in v3: - add note to commit message - move switch statement into if(touch_ret == 0) branch - add MODULE_AUTHOR Changes in v2: - do not change spacing in Kconfig - make struct mfd_cell part of struct mxs_lradc - use switch instead of if in mxs_lradc_irq_mask - use only necessary header files in mxs_lradc.h - use devm_mfd_add_device - use separate function to register mfd device - change licence to GPL - add copyright drivers/mfd/Kconfig | 17 +++ drivers/mfd/Makefile | 1 + drivers/mfd/mxs-lradc.c | 264 ++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/mxs-lradc.h | 187 ++++++++++++++++++++++++++++++ 4 files changed, 469 insertions(+) create mode 100644 drivers/mfd/mxs-lradc.c create mode 100644 include/linux/mfd/mxs-lradc.hdiff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 55ecdfb..8bbc91b 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig@@ -344,6 +344,23 @@ config MFD_MC13XXX_I2C help Select this if your MC13xxx is connected via an I2C bus. +config MFD_MXS_LRADC + tristate "Freescale i.MX23/i.MX28 LRADC" + depends on ARCH_MXS || COMPILE_TEST + select MFD_CORE + select STMP_DEVICE + help + Say yes here to build support for the Low Resolution + Analog-to-Digital Converter (LRADC) found on the i.MX23 and i.MX28 + processors. This driver provides common support for accessing the + device, additional drivers must be enabled in order to use the + functionality of the device: + mxs-lradc-adc for ADC readings + mxs-lradc-ts for touchscreen support + + This driver can also be built as a module. If so, the module will be + called mxs-lradc. + config MFD_MX25_TSADC tristate "Freescale i.MX25 integrated Touchscreen and ADC unit" select REGMAP_MMIOdiff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 31ce076..790698a 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile@@ -215,3 +215,4 @@ obj-$(CONFIG_MFD_ALTERA_A10SR) += altera-a10sr.o obj-$(CONFIG_MFD_SUN4I_GPADC) += sun4i-gpadc.o obj-$(CONFIG_MFD_STM32_TIMERS) += stm32-timers.o +obj-$(CONFIG_MFD_MXS_LRADC) += mxs-lradc.odiff --git a/drivers/mfd/mxs-lradc.c b/drivers/mfd/mxs-lradc.c new file mode 100644 index 0000000..2ae8487 --- /dev/null +++ b/drivers/mfd/mxs-lradc.c@@ -0,0 +1,264 @@ +/* + * Freescale MXS Low Resolution Analog-to-Digital Converter driver + * + * Copyright (c) 2012 DENX Software Engineering, GmbH. + * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com> + * + * Authors: + * Marek Vasut <marex@denx.de> + * Ksenija Stanojevic <ksenija.stanojevic@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/mfd/core.h> +#include <linux/mfd/mxs-lradc.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define ADC_CELL 0 +#define TSC_CELL 1 +#define RES_MEM 0 + +enum mx23_lradc_irqs { + MX23_LRADC_TS_IRQ = 0, + MX23_LRADC_CH0_IRQ, + MX23_LRADC_CH1_IRQ, + MX23_LRADC_CH2_IRQ, + MX23_LRADC_CH3_IRQ, + MX23_LRADC_CH4_IRQ, + MX23_LRADC_CH5_IRQ, + MX23_LRADC_CH6_IRQ, + MX23_LRADC_CH7_IRQ, +}; + +enum mx28_lradc_irqs { + MX28_LRADC_TS_IRQ = 0, + MX28_LRADC_TRESH0_IRQ, + MX28_LRADC_TRESH1_IRQ, + MX28_LRADC_CH0_IRQ, + MX28_LRADC_CH1_IRQ, + MX28_LRADC_CH2_IRQ, + MX28_LRADC_CH3_IRQ, + MX28_LRADC_CH4_IRQ, + MX28_LRADC_CH5_IRQ, + MX28_LRADC_CH6_IRQ, + MX28_LRADC_CH7_IRQ, + MX28_LRADC_BUTTON0_IRQ, + MX28_LRADC_BUTTON1_IRQ, +}; + +static struct resource mx23_adc_resources[] = { + DEFINE_RES_MEM(0x0, 0x0), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"), +}; + +static struct resource mx23_touchscreen_resources[] = { + DEFINE_RES_MEM(0x0, 0x0), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"), + DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"), +}; + +static struct resource mx28_adc_resources[] = { + DEFINE_RES_MEM(0x0, 0x0), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"), +}; + +static struct resource mx28_touchscreen_resources[] = { + DEFINE_RES_MEM(0x0, 0x0), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"), + DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"), +}; + +static struct mfd_cell mx23_cells[] = { + { + .name = "mxs-lradc-adc", + .resources = mx23_adc_resources, + .num_resources = ARRAY_SIZE(mx23_adc_resources), + }, + { + .name = "mxs-lradc-ts", + .resources = mx23_touchscreen_resources, + .num_resources = ARRAY_SIZE(mx23_touchscreen_resources), + }, +}; + +static struct mfd_cell mx28_cells[] = { + { + .name = "mxs-lradc-adc", + .resources = mx28_adc_resources, + .num_resources = ARRAY_SIZE(mx28_adc_resources), + }, + { + .name = "mxs-lradc-ts", + .resources = mx28_touchscreen_resources, + .num_resources = ARRAY_SIZE(mx28_touchscreen_resources), + } +}; + +static const struct of_device_id mxs_lradc_dt_ids[] = { + { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, }, + { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids); + +static int mxs_lradc_probe(struct platform_device *pdev) +{ + const struct of_device_id *of_id; + struct device *dev = &pdev->dev; + struct device_node *node = dev->of_node; + struct mxs_lradc *lradc; + struct mfd_cell *cells = NULL; + struct resource *res; + int ret = 0; + u32 ts_wires = 0; + + lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL); + if (!lradc) + return -ENOMEM; + + of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev); + if (!of_id) + return -EINVAL; + + lradc->soc = (enum mxs_lradc_id)of_id->data; + + lradc->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(lradc->clk)) { + dev_err(dev, "Failed to get the delay unit clock\n"); + return PTR_ERR(lradc->clk); + } + + ret = clk_prepare_enable(lradc->clk); + if (ret) { + dev_err(dev, "Failed to enable the delay unit clock\n"); + return ret; + } + + ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires", + &ts_wires); + + if (!ret) { + lradc->buffer_vchans = BUFFER_VCHANS_LIMITED; + + switch (ts_wires) { + case 4: + lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE; + break; + case 5: + if (lradc->soc == IMX28_LRADC) { + lradc->touchscreen_wire = + MXS_LRADC_TOUCHSCREEN_5WIRE; + break; + } + /* fall through to an error message for i.MX23 */ + default: + dev_err(&pdev->dev, + "Unsupported number of touchscreen wires (%d)\n" + , ts_wires); + ret = -EINVAL; + goto err_clk; + } + } else { + lradc->buffer_vchans = BUFFER_VCHANS_ALL; + } + + platform_set_drvdata(pdev, lradc); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOMEM; + + switch (lradc->soc) { + case IMX23_LRADC: + mx23_adc_resources[RES_MEM] = *res; + mx23_touchscreen_resources[RES_MEM] = *res; + cells = mx23_cells; + break; + case IMX28_LRADC: + mx28_adc_resources[RES_MEM] = *res; + mx28_touchscreen_resources[RES_MEM] = *res; + cells = mx28_cells; + break; + default: + dev_err(dev, "Unsupported SoC\n"); + ret = -ENODEV; + goto err_clk; + } + + ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE, + &cells[ADC_CELL], 1, NULL, 0, NULL); + if (ret) { + dev_err(&pdev->dev, "Failed to add the ADC subdevice\n"); + goto err_clk; + } + + ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE, + &cells[TSC_CELL], 1, NULL, 0, NULL); + if (ret) { + dev_err(&pdev->dev, + "Failed to add the touchscreen subdevice\n"); + goto err_clk; + }
Since touchscreen is optional it doesn't make to try to register it, notice in the touchscreen driver there is no touchscreen, give the user a confusing error and finally disable the clock. Here are my suggestions: 1) Use the solution from Patch V6 but with an explaining comment that touchscreen is optional if (!lradc->touchscreen_wire) return 0; 2) Return a special error from touchscreen registration so mfd knowns this result is expected. I'm open for better solutions. @Lee: What's your opinion?