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authorNicolas Pitre <nicolas.pitre@linaro.org>2011-07-21 21:48:13 -0400
committerNicolas Pitre <nicolas.pitre@linaro.org>2011-07-21 21:48:13 -0400
commitf25718e8cff17b5c64ad11c2a6e9d2ee1b676eef (patch)
treee0368d1f4a4b21cfbc1a04f216580ae6b913d1ea /drivers/gpio/janz-ttl.c
parentc7e0c8535d73f8c5bf760926a2bd71c9840cf2ef (diff)
downloadorigen-f25718e8cff17b5c64ad11c2a6e9d2ee1b676eef.tar.gz
Revert "Merge remote-tracking branch 'arm-soc/for-next' into linaro-3.0"
This reverts commit c7e0c8535d73f8c5bf760926a2bd71c9840cf2ef, reversing changes made to dfee09c8acf18e84fe197bb5d821d1e4e02d020f. John Stultz reports that Panda doesn't boot anymore and 'git bisect' indicated the merge commit itself as the culprit. The resulting kernel log is: [ 1.734802] OMAP DSS rev 4.0 [ 1.740417] omap_hwmod: dss_core: _wait_target_disable failed [ 1.746429] omap_device: omapdss_dss.-1: new worst case deactivate latency 01 [ 1.755035] omapdss DISPC error: can't get dss_clk [ 1.760101] omapdss_dispc: probe of omapdss_dispc failed with error -2 [ 1.767333] omapdss HDMI error: can't get hdmi_clk [ 1.772399] omapdss_hdmi: probe of omapdss_hdmi failed with error -2 [ 1.780273] ------------[ cut here ]------------ [ 1.785125] WARNING: at drivers/video/omap2/dss/dispc.c:553dispc_runtime_ge) [ 1.793640] Modules linked in: [ 1.796905] ---[ end trace 6fcb132ac310d004 ]--- [ 1.801757] Unable to handle kernel NULL pointer dereference at virtualaddr0 [...] Revert it so a later version of the arm-soc merge result can be used instead.
Diffstat (limited to 'drivers/gpio/janz-ttl.c')
-rw-r--r--drivers/gpio/janz-ttl.c258
1 files changed, 258 insertions, 0 deletions
diff --git a/drivers/gpio/janz-ttl.c b/drivers/gpio/janz-ttl.c
new file mode 100644
index 00000000000..813ac077e5d
--- /dev/null
+++ b/drivers/gpio/janz-ttl.c
@@ -0,0 +1,258 @@
+/*
+ * Janz MODULbus VMOD-TTL GPIO Driver
+ *
+ * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+
+#include <linux/mfd/janz.h>
+
+#define DRV_NAME "janz-ttl"
+
+#define PORTA_DIRECTION 0x23
+#define PORTB_DIRECTION 0x2B
+#define PORTC_DIRECTION 0x06
+#define PORTA_IOCTL 0x24
+#define PORTB_IOCTL 0x2C
+#define PORTC_IOCTL 0x07
+
+#define MASTER_INT_CTL 0x00
+#define MASTER_CONF_CTL 0x01
+
+#define CONF_PAE (1 << 2)
+#define CONF_PBE (1 << 7)
+#define CONF_PCE (1 << 4)
+
+struct ttl_control_regs {
+ __be16 portc;
+ __be16 portb;
+ __be16 porta;
+ __be16 control;
+};
+
+struct ttl_module {
+ struct gpio_chip gpio;
+
+ /* base address of registers */
+ struct ttl_control_regs __iomem *regs;
+
+ u8 portc_shadow;
+ u8 portb_shadow;
+ u8 porta_shadow;
+
+ spinlock_t lock;
+};
+
+static int ttl_get_value(struct gpio_chip *gpio, unsigned offset)
+{
+ struct ttl_module *mod = dev_get_drvdata(gpio->dev);
+ u8 *shadow;
+ int ret;
+
+ if (offset < 8) {
+ shadow = &mod->porta_shadow;
+ } else if (offset < 16) {
+ shadow = &mod->portb_shadow;
+ offset -= 8;
+ } else {
+ shadow = &mod->portc_shadow;
+ offset -= 16;
+ }
+
+ spin_lock(&mod->lock);
+ ret = *shadow & (1 << offset);
+ spin_unlock(&mod->lock);
+ return ret;
+}
+
+static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value)
+{
+ struct ttl_module *mod = dev_get_drvdata(gpio->dev);
+ void __iomem *port;
+ u8 *shadow;
+
+ if (offset < 8) {
+ port = &mod->regs->porta;
+ shadow = &mod->porta_shadow;
+ } else if (offset < 16) {
+ port = &mod->regs->portb;
+ shadow = &mod->portb_shadow;
+ offset -= 8;
+ } else {
+ port = &mod->regs->portc;
+ shadow = &mod->portc_shadow;
+ offset -= 16;
+ }
+
+ spin_lock(&mod->lock);
+ if (value)
+ *shadow |= (1 << offset);
+ else
+ *shadow &= ~(1 << offset);
+
+ iowrite16be(*shadow, port);
+ spin_unlock(&mod->lock);
+}
+
+static void __devinit ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val)
+{
+ iowrite16be(reg, &mod->regs->control);
+ iowrite16be(val, &mod->regs->control);
+}
+
+static void __devinit ttl_setup_device(struct ttl_module *mod)
+{
+ /* reset the device to a known state */
+ iowrite16be(0x0000, &mod->regs->control);
+ iowrite16be(0x0001, &mod->regs->control);
+ iowrite16be(0x0000, &mod->regs->control);
+
+ /* put all ports in open-drain mode */
+ ttl_write_reg(mod, PORTA_IOCTL, 0x00ff);
+ ttl_write_reg(mod, PORTB_IOCTL, 0x00ff);
+ ttl_write_reg(mod, PORTC_IOCTL, 0x000f);
+
+ /* set all ports as outputs */
+ ttl_write_reg(mod, PORTA_DIRECTION, 0x0000);
+ ttl_write_reg(mod, PORTB_DIRECTION, 0x0000);
+ ttl_write_reg(mod, PORTC_DIRECTION, 0x0000);
+
+ /* set all ports to drive zeroes */
+ iowrite16be(0x0000, &mod->regs->porta);
+ iowrite16be(0x0000, &mod->regs->portb);
+ iowrite16be(0x0000, &mod->regs->portc);
+
+ /* enable all ports */
+ ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE);
+}
+
+static int __devinit ttl_probe(struct platform_device *pdev)
+{
+ struct janz_platform_data *pdata;
+ struct device *dev = &pdev->dev;
+ struct ttl_module *mod;
+ struct gpio_chip *gpio;
+ struct resource *res;
+ int ret;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(dev, "no platform data\n");
+ ret = -ENXIO;
+ goto out_return;
+ }
+
+ mod = kzalloc(sizeof(*mod), GFP_KERNEL);
+ if (!mod) {
+ dev_err(dev, "unable to allocate private data\n");
+ ret = -ENOMEM;
+ goto out_return;
+ }
+
+ platform_set_drvdata(pdev, mod);
+ spin_lock_init(&mod->lock);
+
+ /* get access to the MODULbus registers for this module */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "MODULbus registers not found\n");
+ ret = -ENODEV;
+ goto out_free_mod;
+ }
+
+ mod->regs = ioremap(res->start, resource_size(res));
+ if (!mod->regs) {
+ dev_err(dev, "MODULbus registers not ioremap\n");
+ ret = -ENOMEM;
+ goto out_free_mod;
+ }
+
+ ttl_setup_device(mod);
+
+ /* Initialize the GPIO data structures */
+ gpio = &mod->gpio;
+ gpio->dev = &pdev->dev;
+ gpio->label = pdev->name;
+ gpio->get = ttl_get_value;
+ gpio->set = ttl_set_value;
+ gpio->owner = THIS_MODULE;
+
+ /* request dynamic allocation */
+ gpio->base = -1;
+ gpio->ngpio = 20;
+
+ ret = gpiochip_add(gpio);
+ if (ret) {
+ dev_err(dev, "unable to add GPIO chip\n");
+ goto out_iounmap_regs;
+ }
+
+ dev_info(&pdev->dev, "module %d: registered GPIO device\n",
+ pdata->modno);
+ return 0;
+
+out_iounmap_regs:
+ iounmap(mod->regs);
+out_free_mod:
+ kfree(mod);
+out_return:
+ return ret;
+}
+
+static int __devexit ttl_remove(struct platform_device *pdev)
+{
+ struct ttl_module *mod = platform_get_drvdata(pdev);
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ ret = gpiochip_remove(&mod->gpio);
+ if (ret) {
+ dev_err(dev, "unable to remove GPIO chip\n");
+ return ret;
+ }
+
+ iounmap(mod->regs);
+ kfree(mod);
+ return 0;
+}
+
+static struct platform_driver ttl_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = ttl_probe,
+ .remove = __devexit_p(ttl_remove),
+};
+
+static int __init ttl_init(void)
+{
+ return platform_driver_register(&ttl_driver);
+}
+
+static void __exit ttl_exit(void)
+{
+ platform_driver_unregister(&ttl_driver);
+}
+
+MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
+MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:janz-ttl");
+
+module_init(ttl_init);
+module_exit(ttl_exit);