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wifipineapple-openwrt/target/linux/brcm2708/patches-3.10/015-bcm2708-i2c-driver.patch

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--- /dev/null
+++ b/drivers/i2c/busses/i2c-bcm2708.c
@@ -0,0 +1,408 @@
+/*
+ * Driver for Broadcom BCM2708 BSC Controllers
+ *
+ * Copyright (C) 2012 Chris Boot & Frank Buss
+ *
+ * This driver is inspired by:
+ * i2c-ocores.c, by Peter Korsgaard <jacmet@sunsite.dk>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+/* BSC register offsets */
+#define BSC_C 0x00
+#define BSC_S 0x04
+#define BSC_DLEN 0x08
+#define BSC_A 0x0c
+#define BSC_FIFO 0x10
+#define BSC_DIV 0x14
+#define BSC_DEL 0x18
+#define BSC_CLKT 0x1c
+
+/* Bitfields in BSC_C */
+#define BSC_C_I2CEN 0x00008000
+#define BSC_C_INTR 0x00000400
+#define BSC_C_INTT 0x00000200
+#define BSC_C_INTD 0x00000100
+#define BSC_C_ST 0x00000080
+#define BSC_C_CLEAR_1 0x00000020
+#define BSC_C_CLEAR_2 0x00000010
+#define BSC_C_READ 0x00000001
+
+/* Bitfields in BSC_S */
+#define BSC_S_CLKT 0x00000200
+#define BSC_S_ERR 0x00000100
+#define BSC_S_RXF 0x00000080
+#define BSC_S_TXE 0x00000040
+#define BSC_S_RXD 0x00000020
+#define BSC_S_TXD 0x00000010
+#define BSC_S_RXR 0x00000008
+#define BSC_S_TXW 0x00000004
+#define BSC_S_DONE 0x00000002
+#define BSC_S_TA 0x00000001
+
+#define I2C_TIMEOUT_MS 150
+
+#define DRV_NAME "bcm2708_i2c"
+
+static unsigned int baudrate = CONFIG_I2C_BCM2708_BAUDRATE;
+module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+MODULE_PARM_DESC(baudrate, "The I2C baudrate");
+
+
+struct bcm2708_i2c {
+ struct i2c_adapter adapter;
+
+ spinlock_t lock;
+ void __iomem *base;
+ int irq;
+ struct clk *clk;
+
+ struct completion done;
+
+ struct i2c_msg *msg;
+ int pos;
+ int nmsgs;
+ bool error;
+};
+
+/*
+ * This function sets the ALT mode on the I2C pins so that we can use them with
+ * the BSC hardware.
+ *
+ * FIXME: This is a hack. Use pinmux / pinctrl.
+ */
+static void bcm2708_i2c_init_pinmode(int id)
+{
+#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
+#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
+
+ int pin;
+ u32 *gpio = ioremap(0x20200000, SZ_16K);
+
+ BUG_ON(id != 0 && id != 1);
+ /* BSC0 is on GPIO 0 & 1, BSC1 is on GPIO 2 & 3 */
+ for (pin = id*2+0; pin <= id*2+1; pin++) {
+printk("bcm2708_i2c_init_pinmode(%d,%d)\n", id, pin);
+ INP_GPIO(pin); /* set mode to GPIO input first */
+ SET_GPIO_ALT(pin, 0); /* set mode to ALT 0 */
+ }
+
+ iounmap(gpio);
+
+#undef INP_GPIO
+#undef SET_GPIO_ALT
+}
+
+static inline u32 bcm2708_rd(struct bcm2708_i2c *bi, unsigned reg)
+{
+ return readl(bi->base + reg);
+}
+
+static inline void bcm2708_wr(struct bcm2708_i2c *bi, unsigned reg, u32 val)
+{
+ writel(val, bi->base + reg);
+}
+
+static inline void bcm2708_bsc_reset(struct bcm2708_i2c *bi)
+{
+ bcm2708_wr(bi, BSC_C, 0);
+ bcm2708_wr(bi, BSC_S, BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE);
+}
+
+static inline void bcm2708_bsc_fifo_drain(struct bcm2708_i2c *bi)
+{
+ while ((bcm2708_rd(bi, BSC_S) & BSC_S_RXD) && (bi->pos < bi->msg->len))
+ bi->msg->buf[bi->pos++] = bcm2708_rd(bi, BSC_FIFO);
+}
+
+static inline void bcm2708_bsc_fifo_fill(struct bcm2708_i2c *bi)
+{
+ while ((bcm2708_rd(bi, BSC_S) & BSC_S_TXD) && (bi->pos < bi->msg->len))
+ bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]);
+}
+
+static inline void bcm2708_bsc_setup(struct bcm2708_i2c *bi)
+{
+ unsigned long bus_hz;
+ u32 cdiv;
+ u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1;
+
+ bus_hz = clk_get_rate(bi->clk);
+ cdiv = bus_hz / baudrate;
+
+ if (bi->msg->flags & I2C_M_RD)
+ c |= BSC_C_INTR | BSC_C_READ;
+ else
+ c |= BSC_C_INTT;
+
+ bcm2708_wr(bi, BSC_DIV, cdiv);
+ bcm2708_wr(bi, BSC_A, bi->msg->addr);
+ bcm2708_wr(bi, BSC_DLEN, bi->msg->len);
+ bcm2708_wr(bi, BSC_C, c);
+}
+
+static irqreturn_t bcm2708_i2c_interrupt(int irq, void *dev_id)
+{
+ struct bcm2708_i2c *bi = dev_id;
+ bool handled = true;
+ u32 s;
+
+ spin_lock(&bi->lock);
+
+ /* we may see camera interrupts on the "other" I2C channel
+ Just return if we've not sent anything */
+ if (!bi->nmsgs || !bi->msg )
+ goto early_exit;
+
+ s = bcm2708_rd(bi, BSC_S);
+
+ if (s & (BSC_S_CLKT | BSC_S_ERR)) {
+ bcm2708_bsc_reset(bi);
+ bi->error = true;
+
+ /* wake up our bh */
+ complete(&bi->done);
+ } else if (s & BSC_S_DONE) {
+ bi->nmsgs--;
+
+ if (bi->msg->flags & I2C_M_RD)
+ bcm2708_bsc_fifo_drain(bi);
+
+ bcm2708_bsc_reset(bi);
+
+ if (bi->nmsgs) {
+ /* advance to next message */
+ bi->msg++;
+ bi->pos = 0;
+ bcm2708_bsc_setup(bi);
+ } else {
+ /* wake up our bh */
+ complete(&bi->done);
+ }
+ } else if (s & BSC_S_TXW) {
+ bcm2708_bsc_fifo_fill(bi);
+ } else if (s & BSC_S_RXR) {
+ bcm2708_bsc_fifo_drain(bi);
+ } else {
+ handled = false;
+ }
+
+early_exit:
+ spin_unlock(&bi->lock);
+
+ return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int bcm2708_i2c_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct bcm2708_i2c *bi = adap->algo_data;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&bi->lock, flags);
+
+ INIT_COMPLETION(bi->done);
+ bi->msg = msgs;
+ bi->pos = 0;
+ bi->nmsgs = num;
+ bi->error = false;
+
+ spin_unlock_irqrestore(&bi->lock, flags);
+
+ bcm2708_bsc_setup(bi);
+
+ ret = wait_for_completion_timeout(&bi->done,
+ msecs_to_jiffies(I2C_TIMEOUT_MS));
+ if (ret == 0) {
+ dev_err(&adap->dev, "transfer timed out\n");
+ spin_lock_irqsave(&bi->lock, flags);
+ bcm2708_bsc_reset(bi);
+ spin_unlock_irqrestore(&bi->lock, flags);
+ return -ETIMEDOUT;
+ }
+
+ return bi->error ? -EIO : num;
+}
+
+static u32 bcm2708_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | /*I2C_FUNC_10BIT_ADDR |*/ I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm bcm2708_i2c_algorithm = {
+ .master_xfer = bcm2708_i2c_master_xfer,
+ .functionality = bcm2708_i2c_functionality,
+};
+
+static int bcm2708_i2c_probe(struct platform_device *pdev)
+{
+ struct resource *regs;
+ int irq, err = -ENOMEM;
+ struct clk *clk;
+ struct bcm2708_i2c *bi;
+ struct i2c_adapter *adap;
+
+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!regs) {
+ dev_err(&pdev->dev, "could not get IO memory\n");
+ return -ENXIO;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "could not get IRQ\n");
+ return irq;
+ }
+
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "could not find clk: %ld\n", PTR_ERR(clk));
+ return PTR_ERR(clk);
+ }
+
+ bcm2708_i2c_init_pinmode(pdev->id);
+
+ bi = kzalloc(sizeof(*bi), GFP_KERNEL);
+ if (!bi)
+ goto out_clk_put;
+
+ platform_set_drvdata(pdev, bi);
+
+ adap = &bi->adapter;
+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_DDC;
+ adap->algo = &bcm2708_i2c_algorithm;
+ adap->algo_data = bi;
+ adap->dev.parent = &pdev->dev;
+ adap->nr = pdev->id;
+ strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
+
+ switch (pdev->id) {
+ case 0:
+ adap->class = I2C_CLASS_HWMON;
+ break;
+ case 1:
+ adap->class = I2C_CLASS_DDC;
+ break;
+ default:
+ dev_err(&pdev->dev, "can only bind to BSC 0 or 1\n");
+ err = -ENXIO;
+ goto out_free_bi;
+ }
+
+ spin_lock_init(&bi->lock);
+ init_completion(&bi->done);
+
+ bi->base = ioremap(regs->start, resource_size(regs));
+ if (!bi->base) {
+ dev_err(&pdev->dev, "could not remap memory\n");
+ goto out_free_bi;
+ }
+
+ bi->irq = irq;
+ bi->clk = clk;
+
+ err = request_irq(irq, bcm2708_i2c_interrupt, IRQF_SHARED,
+ dev_name(&pdev->dev), bi);
+ if (err) {
+ dev_err(&pdev->dev, "could not request IRQ: %d\n", err);
+ goto out_iounmap;
+ }
+
+ bcm2708_bsc_reset(bi);
+
+ err = i2c_add_numbered_adapter(adap);
+ if (err < 0) {
+ dev_err(&pdev->dev, "could not add I2C adapter: %d\n", err);
+ goto out_free_irq;
+ }
+
+ dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %dk)\n",
+ pdev->id, (unsigned long)regs->start, irq, baudrate/1000);
+
+ return 0;
+
+out_free_irq:
+ free_irq(bi->irq, bi);
+out_iounmap:
+ iounmap(bi->base);
+out_free_bi:
+ kfree(bi);
+out_clk_put:
+ clk_put(clk);
+ return err;
+}
+
+static int bcm2708_i2c_remove(struct platform_device *pdev)
+{
+ struct bcm2708_i2c *bi = platform_get_drvdata(pdev);
+
+ platform_set_drvdata(pdev, NULL);
+
+ i2c_del_adapter(&bi->adapter);
+ free_irq(bi->irq, bi);
+ iounmap(bi->base);
+ clk_disable(bi->clk);
+ clk_put(bi->clk);
+ kfree(bi);
+
+ return 0;
+}
+
+static struct platform_driver bcm2708_i2c_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = bcm2708_i2c_probe,
+ .remove = bcm2708_i2c_remove,
+};
+
+// module_platform_driver(bcm2708_i2c_driver);
+
+
+static int __init bcm2708_i2c_init(void)
+{
+ return platform_driver_register(&bcm2708_i2c_driver);
+}
+
+static void __exit bcm2708_i2c_exit(void)
+{
+ platform_driver_unregister(&bcm2708_i2c_driver);
+}
+
+module_init(bcm2708_i2c_init);
+module_exit(bcm2708_i2c_exit);
+
+
+
+MODULE_DESCRIPTION("BSC controller driver for Broadcom BCM2708");
+MODULE_AUTHOR("Chris Boot <bootc@bootc.net>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -344,6 +344,25 @@ config I2C_BCM2835
This support is also available as a module. If so, the module
will be called i2c-bcm2835.
+config I2C_BCM2708
+ tristate "BCM2708 BSC"
+ depends on MACH_BCM2708
+ help
+ Enabling this option will add BSC (Broadcom Serial Controller)
+ support for the BCM2708. BSC is a Broadcom proprietary bus compatible
+ with I2C/TWI/SMBus.
+
+config I2C_BCM2708_BAUDRATE
+ prompt "BCM2708 I2C baudrate"
+ depends on I2C_BCM2708
+ int
+ default 100000
+ help
+ Set the I2C baudrate. This will alter the default value. A
+ different baudrate can be set by using a module parameter as well. If
+ no parameter is provided when loading, this is the value that will be
+ used.
+
config I2C_BLACKFIN_TWI
tristate "Blackfin TWI I2C support"
depends on BLACKFIN
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powerm
obj-$(CONFIG_I2C_AT91) += i2c-at91.o
obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
obj-$(CONFIG_I2C_BCM2835) += i2c-bcm2835.o
+obj-$(CONFIG_I2C_BCM2708) += i2c-bcm2708.o
obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o
obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
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