diff options
Diffstat (limited to 'drivers/mfd/ab4500-core.c')
| -rw-r--r-- | drivers/mfd/ab4500-core.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/drivers/mfd/ab4500-core.c b/drivers/mfd/ab4500-core.c new file mode 100644 index 00000000000..1c44c19e073 --- /dev/null +++ b/drivers/mfd/ab4500-core.c @@ -0,0 +1,208 @@ +/* + * Copyright (C) 2009 ST-Ericsson + * + * Author: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com> + * + * This program is free software; you can redistribute it + * and/or modify it under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation. + * + * AB4500 is a companion power management chip used with U8500. + * On this platform, this is interfaced with SSP0 controller + * which is a ARM primecell pl022. + * + * At the moment the module just exports read/write features. + * Interrupt management to be added - TODO. + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> +#include <linux/mfd/ab4500.h> + +/* just required if probe fails, we need to + * unregister the device + */ +static struct spi_driver ab4500_driver; + +/* + * This funtion writes to any AB4500 registers using + * SPI protocol & before it writes it packs the data + * in the below 24 bit frame format + * + * *|------------------------------------| + * *| 23|22...18|17.......10|9|8|7......0| + * *| r/w bank adr data | + * * ------------------------------------ + * + * This function shouldn't be called from interrupt + * context + */ +int ab4500_write(struct ab4500 *ab4500, unsigned char block, + unsigned long addr, unsigned char data) +{ + struct spi_transfer xfer; + struct spi_message msg; + int err; + unsigned long spi_data = + block << 18 | addr << 10 | data; + + mutex_lock(&ab4500->lock); + ab4500->tx_buf[0] = spi_data; + ab4500->rx_buf[0] = 0; + + xfer.tx_buf = ab4500->tx_buf; + xfer.rx_buf = NULL; + xfer.len = sizeof(unsigned long); + + spi_message_init(&msg); + spi_message_add_tail(&xfer, &msg); + + err = spi_sync(ab4500->spi, &msg); + mutex_unlock(&ab4500->lock); + + return err; +} +EXPORT_SYMBOL(ab4500_write); + +int ab4500_read(struct ab4500 *ab4500, unsigned char block, + unsigned long addr) +{ + struct spi_transfer xfer; + struct spi_message msg; + unsigned long spi_data = + 1 << 23 | block << 18 | addr << 10; + + mutex_lock(&ab4500->lock); + ab4500->tx_buf[0] = spi_data; + ab4500->rx_buf[0] = 0; + + xfer.tx_buf = ab4500->tx_buf; + xfer.rx_buf = ab4500->rx_buf; + xfer.len = sizeof(unsigned long); + + spi_message_init(&msg); + spi_message_add_tail(&xfer, &msg); + + spi_sync(ab4500->spi, &msg); + mutex_unlock(&ab4500->lock); + + return ab4500->rx_buf[0]; +} +EXPORT_SYMBOL(ab4500_read); + +/* ref: ab3100 core */ +#define AB4500_DEVICE(devname, devid) \ +static struct platform_device ab4500_##devname##_device = { \ + .name = devid, \ + .id = -1, \ +} + +/* list of childern devices of ab4500 - all are + * not populated here - TODO + */ +AB4500_DEVICE(charger, "ab4500-charger"); +AB4500_DEVICE(audio, "ab4500-audio"); +AB4500_DEVICE(usb, "ab4500-usb"); +AB4500_DEVICE(tvout, "ab4500-tvout"); +AB4500_DEVICE(sim, "ab4500-sim"); +AB4500_DEVICE(gpadc, "ab4500-gpadc"); +AB4500_DEVICE(clkmgt, "ab4500-clkmgt"); +AB4500_DEVICE(misc, "ab4500-misc"); + +static struct platform_device *ab4500_platform_devs[] = { + &ab4500_charger_device, + &ab4500_audio_device, + &ab4500_usb_device, + &ab4500_tvout_device, + &ab4500_sim_device, + &ab4500_gpadc_device, + &ab4500_clkmgt_device, + &ab4500_misc_device, +}; + +static int __init ab4500_probe(struct spi_device *spi) +{ + struct ab4500 *ab4500; + unsigned char revision; + int err = 0; + int i; + + ab4500 = kzalloc(sizeof *ab4500, GFP_KERNEL); + if (!ab4500) { + dev_err(&spi->dev, "could not allocate AB4500\n"); + err = -ENOMEM; + goto not_detect; + } + + ab4500->spi = spi; + spi_set_drvdata(spi, ab4500); + + mutex_init(&ab4500->lock); + + /* read the revision register */ + revision = ab4500_read(ab4500, AB4500_MISC, AB4500_REV_REG); + + /* revision id 0x0 is for early drop, 0x10 is for cut1.0 */ + if (revision == 0x0 || revision == 0x10) + dev_info(&spi->dev, "Detected chip: %s, revision = %x\n", + ab4500_driver.driver.name, revision); + else { + dev_err(&spi->dev, "unknown chip: 0x%x\n", revision); + goto not_detect; + } + + for (i = 0; i < ARRAY_SIZE(ab4500_platform_devs); i++) { + ab4500_platform_devs[i]->dev.parent = + &spi->dev; + platform_set_drvdata(ab4500_platform_devs[i], ab4500); + } + + /* register the ab4500 platform devices */ + platform_add_devices(ab4500_platform_devs, + ARRAY_SIZE(ab4500_platform_devs)); + + return err; + + not_detect: + spi_unregister_driver(&ab4500_driver); + kfree(ab4500); + return err; +} + +static int __devexit ab4500_remove(struct spi_device *spi) +{ + struct ab4500 *ab4500 = + spi_get_drvdata(spi); + + kfree(ab4500); + + return 0; +} + +static struct spi_driver ab4500_driver = { + .driver = { + .name = "ab4500", + .owner = THIS_MODULE, + }, + .probe = ab4500_probe, + .remove = __devexit_p(ab4500_remove) +}; + +static int __devinit ab4500_init(void) +{ + return spi_register_driver(&ab4500_driver); +} + +static void __exit ab4500_exit(void) +{ + spi_unregister_driver(&ab4500_driver); +} + +subsys_initcall(ab4500_init); +module_exit(ab4500_exit); + +MODULE_AUTHOR("Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com"); +MODULE_DESCRIPTION("AB4500 core driver"); +MODULE_LICENSE("GPL"); |