|  | /* | 
|  | * (C) Copyright 2003-2004 | 
|  | * Humboldt Solutions Ltd, adrian@humboldt.co.uk. | 
|  |  | 
|  | * This is a combined i2c adapter and algorithm driver for the | 
|  | * MPC107/Tsi107 PowerPC northbridge and processors that include | 
|  | * the same I2C unit (8240, 8245, 85xx). | 
|  | * | 
|  | * Release 0.8 | 
|  | * | 
|  | * This file is licensed under the terms of the GNU General Public | 
|  | * License version 2. This program is licensed "as is" without any | 
|  | * warranty of any kind, whether express or implied. | 
|  | */ | 
|  |  | 
|  | #include <linux/config.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/sched.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/pci.h> | 
|  | #include <asm/io.h> | 
|  | #include <linux/fsl_devices.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/delay.h> | 
|  |  | 
|  | #define MPC_I2C_ADDR  0x00 | 
|  | #define MPC_I2C_FDR 	0x04 | 
|  | #define MPC_I2C_CR	0x08 | 
|  | #define MPC_I2C_SR	0x0c | 
|  | #define MPC_I2C_DR	0x10 | 
|  | #define MPC_I2C_DFSRR 0x14 | 
|  | #define MPC_I2C_REGION 0x20 | 
|  |  | 
|  | #define CCR_MEN  0x80 | 
|  | #define CCR_MIEN 0x40 | 
|  | #define CCR_MSTA 0x20 | 
|  | #define CCR_MTX  0x10 | 
|  | #define CCR_TXAK 0x08 | 
|  | #define CCR_RSTA 0x04 | 
|  |  | 
|  | #define CSR_MCF  0x80 | 
|  | #define CSR_MAAS 0x40 | 
|  | #define CSR_MBB  0x20 | 
|  | #define CSR_MAL  0x10 | 
|  | #define CSR_SRW  0x04 | 
|  | #define CSR_MIF  0x02 | 
|  | #define CSR_RXAK 0x01 | 
|  |  | 
|  | struct mpc_i2c { | 
|  | void __iomem *base; | 
|  | u32 interrupt; | 
|  | wait_queue_head_t queue; | 
|  | struct i2c_adapter adap; | 
|  | int irq; | 
|  | u32 flags; | 
|  | }; | 
|  |  | 
|  | static __inline__ void writeccr(struct mpc_i2c *i2c, u32 x) | 
|  | { | 
|  | writeb(x, i2c->base + MPC_I2C_CR); | 
|  | } | 
|  |  | 
|  | static irqreturn_t mpc_i2c_isr(int irq, void *dev_id, struct pt_regs *regs) | 
|  | { | 
|  | struct mpc_i2c *i2c = dev_id; | 
|  | if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) { | 
|  | /* Read again to allow register to stabilise */ | 
|  | i2c->interrupt = readb(i2c->base + MPC_I2C_SR); | 
|  | writeb(0, i2c->base + MPC_I2C_SR); | 
|  | wake_up_interruptible(&i2c->queue); | 
|  | } | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) | 
|  | { | 
|  | unsigned long orig_jiffies = jiffies; | 
|  | u32 x; | 
|  | int result = 0; | 
|  |  | 
|  | if (i2c->irq == 0) | 
|  | { | 
|  | while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) { | 
|  | schedule(); | 
|  | if (time_after(jiffies, orig_jiffies + timeout)) { | 
|  | pr_debug("I2C: timeout\n"); | 
|  | result = -EIO; | 
|  | break; | 
|  | } | 
|  | } | 
|  | x = readb(i2c->base + MPC_I2C_SR); | 
|  | writeb(0, i2c->base + MPC_I2C_SR); | 
|  | } else { | 
|  | /* Interrupt mode */ | 
|  | result = wait_event_interruptible_timeout(i2c->queue, | 
|  | (i2c->interrupt & CSR_MIF), timeout * HZ); | 
|  |  | 
|  | if (unlikely(result < 0)) | 
|  | pr_debug("I2C: wait interrupted\n"); | 
|  | else if (unlikely(!(i2c->interrupt & CSR_MIF))) { | 
|  | pr_debug("I2C: wait timeout\n"); | 
|  | result = -ETIMEDOUT; | 
|  | } | 
|  |  | 
|  | x = i2c->interrupt; | 
|  | i2c->interrupt = 0; | 
|  | } | 
|  |  | 
|  | if (result < 0) | 
|  | return result; | 
|  |  | 
|  | if (!(x & CSR_MCF)) { | 
|  | pr_debug("I2C: unfinished\n"); | 
|  | return -EIO; | 
|  | } | 
|  |  | 
|  | if (x & CSR_MAL) { | 
|  | pr_debug("I2C: MAL\n"); | 
|  | return -EIO; | 
|  | } | 
|  |  | 
|  | if (writing && (x & CSR_RXAK)) { | 
|  | pr_debug("I2C: No RXAK\n"); | 
|  | /* generate stop */ | 
|  | writeccr(i2c, CCR_MEN); | 
|  | return -EIO; | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static void mpc_i2c_setclock(struct mpc_i2c *i2c) | 
|  | { | 
|  | /* Set clock and filters */ | 
|  | if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) { | 
|  | writeb(0x31, i2c->base + MPC_I2C_FDR); | 
|  | writeb(0x10, i2c->base + MPC_I2C_DFSRR); | 
|  | } else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200) | 
|  | writeb(0x3f, i2c->base + MPC_I2C_FDR); | 
|  | else | 
|  | writel(0x1031, i2c->base + MPC_I2C_FDR); | 
|  | } | 
|  |  | 
|  | static void mpc_i2c_start(struct mpc_i2c *i2c) | 
|  | { | 
|  | /* Clear arbitration */ | 
|  | writeb(0, i2c->base + MPC_I2C_SR); | 
|  | /* Start with MEN */ | 
|  | writeccr(i2c, CCR_MEN); | 
|  | } | 
|  |  | 
|  | static void mpc_i2c_stop(struct mpc_i2c *i2c) | 
|  | { | 
|  | writeccr(i2c, CCR_MEN); | 
|  | } | 
|  |  | 
|  | static int mpc_write(struct mpc_i2c *i2c, int target, | 
|  | const u8 * data, int length, int restart) | 
|  | { | 
|  | int i; | 
|  | unsigned timeout = i2c->adap.timeout; | 
|  | u32 flags = restart ? CCR_RSTA : 0; | 
|  |  | 
|  | /* Start with MEN */ | 
|  | if (!restart) | 
|  | writeccr(i2c, CCR_MEN); | 
|  | /* Start as master */ | 
|  | writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags); | 
|  | /* Write target byte */ | 
|  | writeb((target << 1), i2c->base + MPC_I2C_DR); | 
|  |  | 
|  | if (i2c_wait(i2c, timeout, 1) < 0) | 
|  | return -1; | 
|  |  | 
|  | for (i = 0; i < length; i++) { | 
|  | /* Write data byte */ | 
|  | writeb(data[i], i2c->base + MPC_I2C_DR); | 
|  |  | 
|  | if (i2c_wait(i2c, timeout, 1) < 0) | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int mpc_read(struct mpc_i2c *i2c, int target, | 
|  | u8 * data, int length, int restart) | 
|  | { | 
|  | unsigned timeout = i2c->adap.timeout; | 
|  | int i; | 
|  | u32 flags = restart ? CCR_RSTA : 0; | 
|  |  | 
|  | /* Start with MEN */ | 
|  | if (!restart) | 
|  | writeccr(i2c, CCR_MEN); | 
|  | /* Switch to read - restart */ | 
|  | writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags); | 
|  | /* Write target address byte - this time with the read flag set */ | 
|  | writeb((target << 1) | 1, i2c->base + MPC_I2C_DR); | 
|  |  | 
|  | if (i2c_wait(i2c, timeout, 1) < 0) | 
|  | return -1; | 
|  |  | 
|  | if (length) { | 
|  | if (length == 1) | 
|  | writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); | 
|  | else | 
|  | writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA); | 
|  | /* Dummy read */ | 
|  | readb(i2c->base + MPC_I2C_DR); | 
|  | } | 
|  |  | 
|  | for (i = 0; i < length; i++) { | 
|  | if (i2c_wait(i2c, timeout, 0) < 0) | 
|  | return -1; | 
|  |  | 
|  | /* Generate txack on next to last byte */ | 
|  | if (i == length - 2) | 
|  | writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); | 
|  | /* Generate stop on last byte */ | 
|  | if (i == length - 1) | 
|  | writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK); | 
|  | data[i] = readb(i2c->base + MPC_I2C_DR); | 
|  | } | 
|  |  | 
|  | return length; | 
|  | } | 
|  |  | 
|  | static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | 
|  | { | 
|  | struct i2c_msg *pmsg; | 
|  | int i; | 
|  | int ret = 0; | 
|  | unsigned long orig_jiffies = jiffies; | 
|  | struct mpc_i2c *i2c = i2c_get_adapdata(adap); | 
|  |  | 
|  | mpc_i2c_start(i2c); | 
|  |  | 
|  | /* Allow bus up to 1s to become not busy */ | 
|  | while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) { | 
|  | if (signal_pending(current)) { | 
|  | pr_debug("I2C: Interrupted\n"); | 
|  | return -EINTR; | 
|  | } | 
|  | if (time_after(jiffies, orig_jiffies + HZ)) { | 
|  | pr_debug("I2C: timeout\n"); | 
|  | return -EIO; | 
|  | } | 
|  | schedule(); | 
|  | } | 
|  |  | 
|  | for (i = 0; ret >= 0 && i < num; i++) { | 
|  | pmsg = &msgs[i]; | 
|  | pr_debug("Doing %s %d bytes to 0x%02x - %d of %d messages\n", | 
|  | pmsg->flags & I2C_M_RD ? "read" : "write", | 
|  | pmsg->len, pmsg->addr, i + 1, num); | 
|  | if (pmsg->flags & I2C_M_RD) | 
|  | ret = | 
|  | mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i); | 
|  | else | 
|  | ret = | 
|  | mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i); | 
|  | } | 
|  | mpc_i2c_stop(i2c); | 
|  | return (ret < 0) ? ret : num; | 
|  | } | 
|  |  | 
|  | static u32 mpc_functionality(struct i2c_adapter *adap) | 
|  | { | 
|  | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; | 
|  | } | 
|  |  | 
|  | static struct i2c_algorithm mpc_algo = { | 
|  | .name = "MPC algorithm", | 
|  | .id = I2C_ALGO_MPC107, | 
|  | .master_xfer = mpc_xfer, | 
|  | .functionality = mpc_functionality, | 
|  | }; | 
|  |  | 
|  | static struct i2c_adapter mpc_ops = { | 
|  | .owner = THIS_MODULE, | 
|  | .name = "MPC adapter", | 
|  | .id = I2C_ALGO_MPC107 | I2C_HW_MPC107, | 
|  | .algo = &mpc_algo, | 
|  | .class = I2C_CLASS_HWMON, | 
|  | .timeout = 1, | 
|  | .retries = 1 | 
|  | }; | 
|  |  | 
|  | static int fsl_i2c_probe(struct device *device) | 
|  | { | 
|  | int result = 0; | 
|  | struct mpc_i2c *i2c; | 
|  | struct platform_device *pdev = to_platform_device(device); | 
|  | struct fsl_i2c_platform_data *pdata; | 
|  | struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | 
|  |  | 
|  | pdata = (struct fsl_i2c_platform_data *) pdev->dev.platform_data; | 
|  |  | 
|  | if (!(i2c = kmalloc(sizeof(*i2c), GFP_KERNEL))) { | 
|  | return -ENOMEM; | 
|  | } | 
|  | memset(i2c, 0, sizeof(*i2c)); | 
|  |  | 
|  | i2c->irq = platform_get_irq(pdev, 0); | 
|  | i2c->flags = pdata->device_flags; | 
|  | init_waitqueue_head(&i2c->queue); | 
|  |  | 
|  | i2c->base = ioremap((phys_addr_t)r->start, MPC_I2C_REGION); | 
|  |  | 
|  | if (!i2c->base) { | 
|  | printk(KERN_ERR "i2c-mpc - failed to map controller\n"); | 
|  | result = -ENOMEM; | 
|  | goto fail_map; | 
|  | } | 
|  |  | 
|  | if (i2c->irq != 0) | 
|  | if ((result = request_irq(i2c->irq, mpc_i2c_isr, | 
|  | SA_SHIRQ, "i2c-mpc", i2c)) < 0) { | 
|  | printk(KERN_ERR | 
|  | "i2c-mpc - failed to attach interrupt\n"); | 
|  | goto fail_irq; | 
|  | } | 
|  |  | 
|  | mpc_i2c_setclock(i2c); | 
|  | dev_set_drvdata(device, i2c); | 
|  |  | 
|  | i2c->adap = mpc_ops; | 
|  | i2c_set_adapdata(&i2c->adap, i2c); | 
|  | i2c->adap.dev.parent = &pdev->dev; | 
|  | if ((result = i2c_add_adapter(&i2c->adap)) < 0) { | 
|  | printk(KERN_ERR "i2c-mpc - failed to add adapter\n"); | 
|  | goto fail_add; | 
|  | } | 
|  |  | 
|  | return result; | 
|  |  | 
|  | fail_add: | 
|  | if (i2c->irq != 0) | 
|  | free_irq(i2c->irq, NULL); | 
|  | fail_irq: | 
|  | iounmap(i2c->base); | 
|  | fail_map: | 
|  | kfree(i2c); | 
|  | return result; | 
|  | }; | 
|  |  | 
|  | static int fsl_i2c_remove(struct device *device) | 
|  | { | 
|  | struct mpc_i2c *i2c = dev_get_drvdata(device); | 
|  |  | 
|  | i2c_del_adapter(&i2c->adap); | 
|  | dev_set_drvdata(device, NULL); | 
|  |  | 
|  | if (i2c->irq != 0) | 
|  | free_irq(i2c->irq, i2c); | 
|  |  | 
|  | iounmap(i2c->base); | 
|  | kfree(i2c); | 
|  | return 0; | 
|  | }; | 
|  |  | 
|  | /* Structure for a device driver */ | 
|  | static struct device_driver fsl_i2c_driver = { | 
|  | .name = "fsl-i2c", | 
|  | .bus = &platform_bus_type, | 
|  | .probe = fsl_i2c_probe, | 
|  | .remove = fsl_i2c_remove, | 
|  | }; | 
|  |  | 
|  | static int __init fsl_i2c_init(void) | 
|  | { | 
|  | return driver_register(&fsl_i2c_driver); | 
|  | } | 
|  |  | 
|  | static void __exit fsl_i2c_exit(void) | 
|  | { | 
|  | driver_unregister(&fsl_i2c_driver); | 
|  | } | 
|  |  | 
|  | module_init(fsl_i2c_init); | 
|  | module_exit(fsl_i2c_exit); | 
|  |  | 
|  | MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>"); | 
|  | MODULE_DESCRIPTION | 
|  | ("I2C-Bus adapter for MPC107 bridge and MPC824x/85xx/52xx processors"); | 
|  | MODULE_LICENSE("GPL"); |