mfd: add AB4500 driver
This adds core driver support for AB4500 mixed signal
multimedia & power management chip. This connects to U8500
on the SSP (pl022) and exports read/write functions for
the device to get access to this chip. This also registers
the client devices and sets the parent.
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Andrea Gallo <andrea.gallo@stericsson.com>
Reviewed-by: Mark Brown <broonie@sirena.org.uk>
Reviewed-by: Jean-Christophe <plagnioj@jcrosoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/ab4500-core.c b/drivers/mfd/ab4500-core.c
new file mode 100644
index 0000000..3ad91f7
--- /dev/null
+++ b/drivers/mfd/ab4500-core.c
@@ -0,0 +1,207 @@
+/*
+ * 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_sync(ab4500_init);
+
+MODULE_AUTHOR("Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com");
+MODULE_DESCRIPTION("AB4500 core driver");
+MODULE_LICENSE("GPL");