mirror of https://github.com/hak5/openwrt-owl.git
450 lines
11 KiB
Diff
450 lines
11 KiB
Diff
--- /dev/null
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+++ b/drivers/i2c/busses/i2c-bcm2708.c
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@@ -0,0 +1,408 @@
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+/*
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+ * Driver for Broadcom BCM2708 BSC Controllers
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+ *
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+ * Copyright (C) 2012 Chris Boot & Frank Buss
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+ *
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+ * This driver is inspired by:
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+ * i2c-ocores.c, by Peter Korsgaard <jacmet@sunsite.dk>
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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+ *
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ *
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+ * You should have received a copy of the GNU General Public License
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+ * along with this program; if not, write to the Free Software
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+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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+ */
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+
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+#include <linux/kernel.h>
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+#include <linux/module.h>
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+#include <linux/spinlock.h>
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+#include <linux/clk.h>
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+#include <linux/err.h>
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+#include <linux/platform_device.h>
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+#include <linux/io.h>
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+#include <linux/slab.h>
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+#include <linux/i2c.h>
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+#include <linux/interrupt.h>
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+#include <linux/sched.h>
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+#include <linux/wait.h>
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+
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+/* BSC register offsets */
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+#define BSC_C 0x00
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+#define BSC_S 0x04
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+#define BSC_DLEN 0x08
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+#define BSC_A 0x0c
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+#define BSC_FIFO 0x10
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+#define BSC_DIV 0x14
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+#define BSC_DEL 0x18
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+#define BSC_CLKT 0x1c
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+
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+/* Bitfields in BSC_C */
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+#define BSC_C_I2CEN 0x00008000
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+#define BSC_C_INTR 0x00000400
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+#define BSC_C_INTT 0x00000200
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+#define BSC_C_INTD 0x00000100
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+#define BSC_C_ST 0x00000080
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+#define BSC_C_CLEAR_1 0x00000020
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+#define BSC_C_CLEAR_2 0x00000010
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+#define BSC_C_READ 0x00000001
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+
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+/* Bitfields in BSC_S */
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+#define BSC_S_CLKT 0x00000200
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+#define BSC_S_ERR 0x00000100
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+#define BSC_S_RXF 0x00000080
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+#define BSC_S_TXE 0x00000040
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+#define BSC_S_RXD 0x00000020
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+#define BSC_S_TXD 0x00000010
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+#define BSC_S_RXR 0x00000008
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+#define BSC_S_TXW 0x00000004
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+#define BSC_S_DONE 0x00000002
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+#define BSC_S_TA 0x00000001
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+
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+#define I2C_TIMEOUT_MS 150
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+
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+#define DRV_NAME "bcm2708_i2c"
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+
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+static unsigned int baudrate = CONFIG_I2C_BCM2708_BAUDRATE;
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+module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
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+MODULE_PARM_DESC(baudrate, "The I2C baudrate");
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+
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+
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+struct bcm2708_i2c {
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+ struct i2c_adapter adapter;
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+
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+ spinlock_t lock;
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+ void __iomem *base;
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+ int irq;
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+ struct clk *clk;
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+
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+ struct completion done;
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+
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+ struct i2c_msg *msg;
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+ int pos;
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+ int nmsgs;
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+ bool error;
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+};
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+
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+/*
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+ * This function sets the ALT mode on the I2C pins so that we can use them with
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+ * the BSC hardware.
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+ *
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+ * FIXME: This is a hack. Use pinmux / pinctrl.
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+ */
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+static void bcm2708_i2c_init_pinmode(int id)
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+{
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+#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
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+#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
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+
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+ int pin;
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+ u32 *gpio = ioremap(0x20200000, SZ_16K);
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+
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+ BUG_ON(id != 0 && id != 1);
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+ /* BSC0 is on GPIO 0 & 1, BSC1 is on GPIO 2 & 3 */
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+ for (pin = id*2+0; pin <= id*2+1; pin++) {
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+printk("bcm2708_i2c_init_pinmode(%d,%d)\n", id, pin);
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+ INP_GPIO(pin); /* set mode to GPIO input first */
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+ SET_GPIO_ALT(pin, 0); /* set mode to ALT 0 */
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+ }
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+
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+ iounmap(gpio);
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+
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+#undef INP_GPIO
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+#undef SET_GPIO_ALT
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+}
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+
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+static inline u32 bcm2708_rd(struct bcm2708_i2c *bi, unsigned reg)
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+{
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+ return readl(bi->base + reg);
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+}
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+
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+static inline void bcm2708_wr(struct bcm2708_i2c *bi, unsigned reg, u32 val)
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+{
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+ writel(val, bi->base + reg);
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+}
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+
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+static inline void bcm2708_bsc_reset(struct bcm2708_i2c *bi)
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+{
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+ bcm2708_wr(bi, BSC_C, 0);
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+ bcm2708_wr(bi, BSC_S, BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE);
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+}
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+
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+static inline void bcm2708_bsc_fifo_drain(struct bcm2708_i2c *bi)
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+{
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+ while ((bcm2708_rd(bi, BSC_S) & BSC_S_RXD) && (bi->pos < bi->msg->len))
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+ bi->msg->buf[bi->pos++] = bcm2708_rd(bi, BSC_FIFO);
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+}
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+
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+static inline void bcm2708_bsc_fifo_fill(struct bcm2708_i2c *bi)
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+{
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+ while ((bcm2708_rd(bi, BSC_S) & BSC_S_TXD) && (bi->pos < bi->msg->len))
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+ bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]);
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+}
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+
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+static inline void bcm2708_bsc_setup(struct bcm2708_i2c *bi)
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+{
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+ unsigned long bus_hz;
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+ u32 cdiv;
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+ u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1;
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+
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+ bus_hz = clk_get_rate(bi->clk);
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+ cdiv = bus_hz / baudrate;
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+
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+ if (bi->msg->flags & I2C_M_RD)
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+ c |= BSC_C_INTR | BSC_C_READ;
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+ else
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+ c |= BSC_C_INTT;
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+
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+ bcm2708_wr(bi, BSC_DIV, cdiv);
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+ bcm2708_wr(bi, BSC_A, bi->msg->addr);
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+ bcm2708_wr(bi, BSC_DLEN, bi->msg->len);
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+ bcm2708_wr(bi, BSC_C, c);
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+}
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+
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+static irqreturn_t bcm2708_i2c_interrupt(int irq, void *dev_id)
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+{
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+ struct bcm2708_i2c *bi = dev_id;
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+ bool handled = true;
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+ u32 s;
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+
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+ spin_lock(&bi->lock);
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+
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+ /* we may see camera interrupts on the "other" I2C channel
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+ Just return if we've not sent anything */
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+ if (!bi->nmsgs || !bi->msg )
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+ goto early_exit;
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+
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+ s = bcm2708_rd(bi, BSC_S);
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+
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+ if (s & (BSC_S_CLKT | BSC_S_ERR)) {
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+ bcm2708_bsc_reset(bi);
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+ bi->error = true;
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+
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+ /* wake up our bh */
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+ complete(&bi->done);
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+ } else if (s & BSC_S_DONE) {
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+ bi->nmsgs--;
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+
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+ if (bi->msg->flags & I2C_M_RD)
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+ bcm2708_bsc_fifo_drain(bi);
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+
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+ bcm2708_bsc_reset(bi);
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+
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+ if (bi->nmsgs) {
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+ /* advance to next message */
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+ bi->msg++;
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+ bi->pos = 0;
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+ bcm2708_bsc_setup(bi);
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+ } else {
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+ /* wake up our bh */
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+ complete(&bi->done);
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+ }
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+ } else if (s & BSC_S_TXW) {
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+ bcm2708_bsc_fifo_fill(bi);
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+ } else if (s & BSC_S_RXR) {
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+ bcm2708_bsc_fifo_drain(bi);
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+ } else {
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+ handled = false;
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+ }
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+
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+early_exit:
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+ spin_unlock(&bi->lock);
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+
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+ return handled ? IRQ_HANDLED : IRQ_NONE;
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+}
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+
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+static int bcm2708_i2c_master_xfer(struct i2c_adapter *adap,
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+ struct i2c_msg *msgs, int num)
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+{
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+ struct bcm2708_i2c *bi = adap->algo_data;
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+ unsigned long flags;
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+ int ret;
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+
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+ spin_lock_irqsave(&bi->lock, flags);
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+
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+ INIT_COMPLETION(bi->done);
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+ bi->msg = msgs;
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+ bi->pos = 0;
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+ bi->nmsgs = num;
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+ bi->error = false;
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+
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+ spin_unlock_irqrestore(&bi->lock, flags);
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+
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+ bcm2708_bsc_setup(bi);
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+
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+ ret = wait_for_completion_timeout(&bi->done,
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+ msecs_to_jiffies(I2C_TIMEOUT_MS));
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+ if (ret == 0) {
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+ dev_err(&adap->dev, "transfer timed out\n");
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+ spin_lock_irqsave(&bi->lock, flags);
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+ bcm2708_bsc_reset(bi);
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+ spin_unlock_irqrestore(&bi->lock, flags);
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+ return -ETIMEDOUT;
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+ }
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+
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+ return bi->error ? -EIO : num;
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+}
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+
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+static u32 bcm2708_i2c_functionality(struct i2c_adapter *adap)
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+{
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+ return I2C_FUNC_I2C | /*I2C_FUNC_10BIT_ADDR |*/ I2C_FUNC_SMBUS_EMUL;
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+}
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+
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+static struct i2c_algorithm bcm2708_i2c_algorithm = {
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+ .master_xfer = bcm2708_i2c_master_xfer,
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+ .functionality = bcm2708_i2c_functionality,
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+};
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+
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+static int bcm2708_i2c_probe(struct platform_device *pdev)
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+{
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+ struct resource *regs;
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+ int irq, err = -ENOMEM;
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+ struct clk *clk;
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+ struct bcm2708_i2c *bi;
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+ struct i2c_adapter *adap;
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+
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+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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+ if (!regs) {
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+ dev_err(&pdev->dev, "could not get IO memory\n");
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+ return -ENXIO;
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+ }
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+
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+ irq = platform_get_irq(pdev, 0);
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+ if (irq < 0) {
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+ dev_err(&pdev->dev, "could not get IRQ\n");
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+ return irq;
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+ }
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+
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+ clk = clk_get(&pdev->dev, NULL);
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+ if (IS_ERR(clk)) {
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+ dev_err(&pdev->dev, "could not find clk: %ld\n", PTR_ERR(clk));
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+ return PTR_ERR(clk);
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+ }
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+
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+ bcm2708_i2c_init_pinmode(pdev->id);
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+
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+ bi = kzalloc(sizeof(*bi), GFP_KERNEL);
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+ if (!bi)
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+ goto out_clk_put;
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+
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+ platform_set_drvdata(pdev, bi);
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+
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+ adap = &bi->adapter;
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+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_DDC;
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+ adap->algo = &bcm2708_i2c_algorithm;
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+ adap->algo_data = bi;
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+ adap->dev.parent = &pdev->dev;
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+ adap->nr = pdev->id;
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+ strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
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+
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+ switch (pdev->id) {
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+ case 0:
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+ adap->class = I2C_CLASS_HWMON;
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+ break;
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+ case 1:
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+ adap->class = I2C_CLASS_DDC;
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+ break;
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+ default:
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+ dev_err(&pdev->dev, "can only bind to BSC 0 or 1\n");
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+ err = -ENXIO;
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+ goto out_free_bi;
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+ }
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+
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+ spin_lock_init(&bi->lock);
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+ init_completion(&bi->done);
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+
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+ bi->base = ioremap(regs->start, resource_size(regs));
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+ if (!bi->base) {
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+ dev_err(&pdev->dev, "could not remap memory\n");
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+ goto out_free_bi;
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+ }
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+
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+ bi->irq = irq;
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+ bi->clk = clk;
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+
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+ err = request_irq(irq, bcm2708_i2c_interrupt, IRQF_SHARED,
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+ dev_name(&pdev->dev), bi);
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+ if (err) {
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+ dev_err(&pdev->dev, "could not request IRQ: %d\n", err);
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+ goto out_iounmap;
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+ }
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+
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+ bcm2708_bsc_reset(bi);
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+
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+ err = i2c_add_numbered_adapter(adap);
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+ if (err < 0) {
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+ dev_err(&pdev->dev, "could not add I2C adapter: %d\n", err);
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+ goto out_free_irq;
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+ }
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+
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+ dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %dk)\n",
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+ pdev->id, (unsigned long)regs->start, irq, baudrate/1000);
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+
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+ return 0;
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+
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+out_free_irq:
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+ free_irq(bi->irq, bi);
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+out_iounmap:
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+ iounmap(bi->base);
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+out_free_bi:
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+ kfree(bi);
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+out_clk_put:
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+ clk_put(clk);
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+ return err;
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+}
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+
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+static int bcm2708_i2c_remove(struct platform_device *pdev)
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+{
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+ struct bcm2708_i2c *bi = platform_get_drvdata(pdev);
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+
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+ platform_set_drvdata(pdev, NULL);
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+
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+ i2c_del_adapter(&bi->adapter);
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+ free_irq(bi->irq, bi);
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+ iounmap(bi->base);
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+ clk_disable(bi->clk);
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+ clk_put(bi->clk);
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+ kfree(bi);
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+
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+ return 0;
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+}
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+
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+static struct platform_driver bcm2708_i2c_driver = {
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+ .driver = {
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+ .name = DRV_NAME,
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+ .owner = THIS_MODULE,
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+ },
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+ .probe = bcm2708_i2c_probe,
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+ .remove = bcm2708_i2c_remove,
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+};
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+
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+// module_platform_driver(bcm2708_i2c_driver);
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+
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+
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+static int __init bcm2708_i2c_init(void)
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+{
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+ return platform_driver_register(&bcm2708_i2c_driver);
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+}
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+
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+static void __exit bcm2708_i2c_exit(void)
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+{
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+ platform_driver_unregister(&bcm2708_i2c_driver);
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+}
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+
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+module_init(bcm2708_i2c_init);
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+module_exit(bcm2708_i2c_exit);
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+
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+
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+
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+MODULE_DESCRIPTION("BSC controller driver for Broadcom BCM2708");
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+MODULE_AUTHOR("Chris Boot <bootc@bootc.net>");
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+MODULE_LICENSE("GPL v2");
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+MODULE_ALIAS("platform:" DRV_NAME);
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--- a/drivers/i2c/busses/Kconfig
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+++ b/drivers/i2c/busses/Kconfig
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@@ -344,6 +344,25 @@ config I2C_BCM2835
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This support is also available as a module. If so, the module
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will be called i2c-bcm2835.
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+config I2C_BCM2708
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+ tristate "BCM2708 BSC"
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+ depends on MACH_BCM2708
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+ help
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+ Enabling this option will add BSC (Broadcom Serial Controller)
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+ support for the BCM2708. BSC is a Broadcom proprietary bus compatible
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+ with I2C/TWI/SMBus.
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+
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+config I2C_BCM2708_BAUDRATE
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+ prompt "BCM2708 I2C baudrate"
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+ depends on I2C_BCM2708
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+ int
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+ default 100000
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+ help
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+ Set the I2C baudrate. This will alter the default value. A
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+ different baudrate can be set by using a module parameter as well. If
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+ no parameter is provided when loading, this is the value that will be
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+ used.
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+
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config I2C_BLACKFIN_TWI
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tristate "Blackfin TWI I2C support"
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depends on BLACKFIN
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--- a/drivers/i2c/busses/Makefile
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+++ b/drivers/i2c/busses/Makefile
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@@ -32,6 +32,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powerm
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obj-$(CONFIG_I2C_AT91) += i2c-at91.o
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obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
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obj-$(CONFIG_I2C_BCM2835) += i2c-bcm2835.o
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+obj-$(CONFIG_I2C_BCM2708) += i2c-bcm2708.o
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obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
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obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o
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obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
|