This patch adds a minimal driver for the Freescale i.MX23, i.MX28 power subsystem. It's required to trigger the probing of the underlying drivers like on-chip regulators. Additionally the drivers supports the configuration of the DC-DC clock frequency to avoid possible interferences.
Signed-off-by: Stefan Wahren <[email protected]> --- drivers/power/Kconfig | 8 ++ drivers/power/Makefile | 1 + drivers/power/mxs_power.c | 226 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 235 insertions(+) create mode 100644 drivers/power/mxs_power.c diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig index 0108c2a..8a3eaa4 100644 --- a/drivers/power/Kconfig +++ b/drivers/power/Kconfig @@ -43,6 +43,14 @@ config MAX8925_POWER Say Y here to enable support for the battery charger in the Maxim MAX8925 PMIC. +config MXS_POWER + tristate "Freescale MXS power subsystem support" + depends on ARCH_MXS + help + Say Y here to enable support for the Freescale i.MX23/i.MX28 + power subsystem. This is a requirement to get access to on-chip + regulators, battery charger and many more. + config WM831X_BACKUP tristate "WM831X backup battery charger support" depends on MFD_WM831X diff --git a/drivers/power/Makefile b/drivers/power/Makefile index dfa8942..91c0a62 100644 --- a/drivers/power/Makefile +++ b/drivers/power/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_GENERIC_ADC_BATTERY) += generic-adc-battery.o obj-$(CONFIG_PDA_POWER) += pda_power.o obj-$(CONFIG_APM_POWER) += apm_power.o obj-$(CONFIG_MAX8925_POWER) += max8925_power.o +obj-$(CONFIG_MXS_POWER) += mxs_power.o obj-$(CONFIG_WM831X_BACKUP) += wm831x_backup.o obj-$(CONFIG_WM831X_POWER) += wm831x_power.o obj-$(CONFIG_WM8350_POWER) += wm8350_power.o diff --git a/drivers/power/mxs_power.c b/drivers/power/mxs_power.c new file mode 100644 index 0000000..6b68064 --- /dev/null +++ b/drivers/power/mxs_power.c @@ -0,0 +1,226 @@ +/* + * Freescale MXS power subsystem + * + * Copyright (C) 2014 Stefan Wahren + * + * Inspired by imx-bootlets + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/power_supply.h> +#include <linux/types.h> + +#define BM_POWER_CTRL_POLARITY_VBUSVALID (1 << 5) +#define BM_POWER_CTRL_VBUSVALID_IRQ (1 << 4) +#define BM_POWER_CTRL_ENIRQ_VBUS_VALID (1 << 3) + +#define HW_POWER_5VCTRL_OFFSET 0x10 +#define HW_POWER_MISC_OFFSET 0x90 + +#define BM_POWER_5VCTRL_VBUSVALID_THRESH (7 << 8) +#define BM_POWER_5VCTRL_PWDN_5VBRNOUT (1 << 7) +#define BM_POWER_5VCTRL_VBUSVALID_5VDETECT (1 << 4) + +#define HW_POWER_5VCTRL_VBUSVALID_THRESH_4_40V (5 << 8) + +#define SHIFT_FREQSEL 4 + +#define BM_POWER_MISC_FREQSEL (7 << SHIFT_FREQSEL) + +#define HW_POWER_MISC_FREQSEL_20000_KHZ 1 +#define HW_POWER_MISC_FREQSEL_24000_KHZ 2 +#define HW_POWER_MISC_FREQSEL_19200_KHZ 3 + +#define HW_POWER_MISC_SEL_PLLCLK (1 << 0) + +static int dcdc_pll; +module_param(dcdc_pll, int, 0); +MODULE_PARM_DESC(dcdc_pll, + "DC-DC PLL frequency (kHz). Use 19200, 20000 or 24000"); + +struct mxs_power_data { + void __iomem *base_addr; + struct power_supply dc; +}; + +int get_dcdc_clk_freq(struct mxs_power_data *pdata) +{ + void __iomem *base = pdata->base_addr; + int ret = -EINVAL; + u32 val; + + val = readl(base + HW_POWER_MISC_OFFSET); + + /* XTAL source */ + if ((val & HW_POWER_MISC_SEL_PLLCLK) == 0) + return 24000; + + switch ((val & BM_POWER_MISC_FREQSEL) >> SHIFT_FREQSEL) { + case HW_POWER_MISC_FREQSEL_20000_KHZ: + ret = 20000; + break; + case HW_POWER_MISC_FREQSEL_24000_KHZ: + ret = 24000; + break; + case HW_POWER_MISC_FREQSEL_19200_KHZ: + ret = 19200; + break; + } + + return ret; +} + +int set_dcdc_clk_freq(struct mxs_power_data *pdata, int kHz) +{ + void __iomem *misc = pdata->base_addr + HW_POWER_MISC_OFFSET; + u32 val; + int ret = 0; + + val = readl(misc); + + val &= ~BM_POWER_MISC_FREQSEL; + val &= ~HW_POWER_MISC_SEL_PLLCLK; + + /* Accept only values recommend by Freescale */ + switch (kHz) { + case 19200: + val |= HW_POWER_MISC_FREQSEL_19200_KHZ << SHIFT_FREQSEL; + break; + case 20000: + val |= HW_POWER_MISC_FREQSEL_20000_KHZ << SHIFT_FREQSEL; + break; + case 24000: + val |= HW_POWER_MISC_FREQSEL_24000_KHZ << SHIFT_FREQSEL; + break; + default: + ret = -EINVAL; + break; + } + + if (ret) + return ret; + + /* First program FREQSEL */ + writel(val, misc); + + /* then set PLL as clk for DC-DC converter */ + writel(val | HW_POWER_MISC_SEL_PLLCLK, misc); + + return 0; +} + +static enum power_supply_property mxs_power_dc_props[] = { + POWER_SUPPLY_PROP_ONLINE, +}; + +static int mxs_power_dc_get_property(struct power_supply *psy, + enum power_supply_property psp, + union power_supply_propval *val) +{ + struct mxs_power_data *data = container_of(psy, + struct mxs_power_data, dc); + int ret = 0; + + switch (psp) { + case POWER_SUPPLY_PROP_ONLINE: + val->intval = 1; + break; + default: + ret = -EINVAL; + break; + } + return ret; +} + +static const struct of_device_id of_mxs_power_match[] = { + { .compatible = "fsl,imx23-power" }, + { .compatible = "fsl,imx28-power" }, + { /* end */ } +}; +MODULE_DEVICE_TABLE(of, of_mxs_power_match); + +static int mxs_power_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct resource *res; + struct mxs_power_data *data; + int ret; + int dcdc_clk_freq; + + if (!np) { + dev_err(dev, "missing device tree\n"); + return -EINVAL; + } + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + data->dc.properties = mxs_power_dc_props; + data->dc.num_properties = ARRAY_SIZE(mxs_power_dc_props); + data->dc.get_property = mxs_power_dc_get_property; + data->dc.name = "dc"; + data->dc.type = POWER_SUPPLY_TYPE_MAINS; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + data->base_addr = devm_ioremap_resource(dev, res); + if (IS_ERR(data->base_addr)) + return PTR_ERR(data->base_addr); + + ret = power_supply_register(dev, &data->dc); + if (ret) + return ret; + + platform_set_drvdata(pdev, data); + + if (dcdc_pll) + set_dcdc_clk_freq(data, dcdc_pll); + + dcdc_clk_freq = get_dcdc_clk_freq(data); + + dev_info(dev, "DCDC clock freq: %d kHz\n", dcdc_clk_freq); + + return of_platform_populate(np, NULL, NULL, dev); +} + +static int mxs_power_remove(struct platform_device *pdev) +{ + struct mxs_power_data *data = platform_get_drvdata(pdev); + + of_platform_depopulate(&pdev->dev); + power_supply_unregister(&data->dc); + + return 0; +} + +static struct platform_driver mxs_power_driver = { + .driver = { + .name = "mxs_power", + .owner = THIS_MODULE, + .of_match_table = of_mxs_power_match, + }, + .probe = mxs_power_probe, + .remove = mxs_power_remove, +}; + +module_platform_driver(mxs_power_driver); + +MODULE_AUTHOR("Stefan Wahren <[email protected]>"); +MODULE_DESCRIPTION("Freescale MXS power subsystem"); +MODULE_LICENSE("GPL v2"); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
