drivers/mfd/htc-pasic3.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Core driver for HTC PASIC3 LED/DS1WM chip.
0004  *
0005  * Copyright (C) 2006 Philipp Zabel <philipp.zabel@gmail.com>
0006  */
0007
0008 #include <linux/init.h>
0009 #include <linux/module.h>
0010 #include <linux/platform_device.h>
0011
0012 #include <linux/gpio.h>
0013 #include <linux/io.h>
0014 #include <linux/irq.h>
0015 #include <linux/interrupt.h>
0016 #include <linux/mfd/core.h>
0017 #include <linux/mfd/ds1wm.h>
0018 #include <linux/mfd/htc-pasic3.h>
0019 #include <linux/slab.h>
0020
0021 struct pasic3_data {
0022     void __iomem *mapping;
0023     unsigned int bus_shift;
0024 };
0025
0026 #define REG_ADDR  5
0027 #define REG_DATA  6
0028
0029 #define READ_MODE 0x80
0030
0031 /*
0032  * write to a secondary register on the PASIC3
0033  */
0034 void pasic3_write_register(struct device *dev, u32 reg, u8 val)
0035 {
0036     struct pasic3_data *asic = dev_get_drvdata(dev);
0037     int bus_shift = asic->bus_shift;
0038     void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
0039     void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
0040
0041     __raw_writeb(~READ_MODE & reg, addr);
0042     __raw_writeb(val, data);
0043 }
0044 EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */
0045
0046 /*
0047  * read from a secondary register on the PASIC3
0048  */
0049 u8 pasic3_read_register(struct device *dev, u32 reg)
0050 {
0051     struct pasic3_data *asic = dev_get_drvdata(dev);
0052     int bus_shift = asic->bus_shift;
0053     void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
0054     void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
0055
0056     __raw_writeb(READ_MODE | reg, addr);
0057     return __raw_readb(data);
0058 }
0059 EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */
0060
0061 /*
0062  * LEDs
0063  */
0064
0065 static struct mfd_cell led_cell __initdata = {
0066     .name = "leds-pasic3",
0067 };
0068
0069 /*
0070  * DS1WM
0071  */
0072
0073 static int ds1wm_enable(struct platform_device *pdev)
0074 {
0075     struct device *dev = pdev->dev.parent;
0076     int c;
0077
0078     c = pasic3_read_register(dev, 0x28);
0079     pasic3_write_register(dev, 0x28, c & 0x7f);
0080
0081     dev_dbg(dev, "DS1WM OWM_EN low (active) %02x\n", c & 0x7f);
0082     return 0;
0083 }
0084
0085 static int ds1wm_disable(struct platform_device *pdev)
0086 {
0087     struct device *dev = pdev->dev.parent;
0088     int c;
0089
0090     c = pasic3_read_register(dev, 0x28);
0091     pasic3_write_register(dev, 0x28, c | 0x80);
0092
0093     dev_dbg(dev, "DS1WM OWM_EN high (inactive) %02x\n", c | 0x80);
0094     return 0;
0095 }
0096
0097 static struct ds1wm_driver_data ds1wm_pdata = {
0098     .active_high = 0,
0099     .reset_recover_delay = 1,
0100 };
0101
0102 static struct resource ds1wm_resources[] __initdata = {
0103     [0] = {
0104         .start  = 0,
0105         .flags  = IORESOURCE_MEM,
0106     },
0107     [1] = {
0108         .start  = 0,
0109         .end    = 0,
0110         .flags  = IORESOURCE_IRQ,
0111     },
0112 };
0113
0114 static const struct mfd_cell ds1wm_cell __initconst = {
0115     .name          = "ds1wm",
0116     .enable        = ds1wm_enable,
0117     .disable       = ds1wm_disable,
0118     .platform_data = &ds1wm_pdata,
0119     .pdata_size    = sizeof(ds1wm_pdata),
0120     .num_resources = 2,
0121     .resources     = ds1wm_resources,
0122 };
0123
0124 static int __init pasic3_probe(struct platform_device *pdev)
0125 {
0126     struct pasic3_platform_data *pdata = dev_get_platdata(&pdev->dev);
0127     struct device *dev = &pdev->dev;
0128     struct pasic3_data *asic;
0129     struct resource *r;
0130     int ret;
0131     int irq = 0;
0132
0133     r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
0134     if (r) {
0135         ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
0136             (IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
0137         irq = r->start;
0138     }
0139
0140     r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0141     if (!r)
0142         return -ENXIO;
0143
0144     if (!request_mem_region(r->start, resource_size(r), "pasic3"))
0145         return -EBUSY;
0146
0147     asic = devm_kzalloc(dev, sizeof(struct pasic3_data), GFP_KERNEL);
0148     if (!asic)
0149         return -ENOMEM;
0150
0151     platform_set_drvdata(pdev, asic);
0152
0153     asic->mapping = ioremap(r->start, resource_size(r));
0154     if (!asic->mapping) {
0155         dev_err(dev, "couldn't ioremap PASIC3\n");
0156         return -ENOMEM;
0157     }
0158
0159     /* calculate bus shift from mem resource */
0160     asic->bus_shift = (resource_size(r) - 5) >> 3;
0161
0162     if (pdata && pdata->clock_rate) {
0163         ds1wm_pdata.clock_rate = pdata->clock_rate;
0164         /* the first 5 PASIC3 registers control the DS1WM */
0165         ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
0166         ret = mfd_add_devices(&pdev->dev, pdev->id,
0167                       &ds1wm_cell, 1, r, irq, NULL);
0168         if (ret < 0)
0169             dev_warn(dev, "failed to register DS1WM\n");
0170     }
0171
0172     if (pdata && pdata->led_pdata) {
0173         led_cell.platform_data = pdata->led_pdata;
0174         led_cell.pdata_size = sizeof(struct pasic3_leds_machinfo);
0175         ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r,
0176                       0, NULL);
0177         if (ret < 0)
0178             dev_warn(dev, "failed to register LED device\n");
0179     }
0180
0181     return 0;
0182 }
0183
0184 static int pasic3_remove(struct platform_device *pdev)
0185 {
0186     struct pasic3_data *asic = platform_get_drvdata(pdev);
0187     struct resource *r;
0188
0189     mfd_remove_devices(&pdev->dev);
0190
0191     iounmap(asic->mapping);
0192     r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0193     release_mem_region(r->start, resource_size(r));
0194     return 0;
0195 }
0196
0197 MODULE_ALIAS("platform:pasic3");
0198
0199 static struct platform_driver pasic3_driver = {
0200     .driver     = {
0201         .name   = "pasic3",
0202     },
0203     .remove     = pasic3_remove,
0204 };
0205
0206 module_platform_driver_probe(pasic3_driver, pasic3_probe);
0207
0208 MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
0209 MODULE_DESCRIPTION("Core driver for HTC PASIC3");
0210 MODULE_LICENSE("GPL");