diff options
Diffstat (limited to 'arch/mips/mti-sead3/sead3-pic32-i2c-drv.c')
| -rw-r--r-- | arch/mips/mti-sead3/sead3-pic32-i2c-drv.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c b/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c new file mode 100644 index 000000000000..46509b0a620d --- /dev/null +++ b/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c @@ -0,0 +1,435 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. + */ +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/platform_device.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/slab.h> + +#define PIC32_I2CxCON 0x0000 +#define PIC32_I2CxCONCLR 0x0004 +#define PIC32_I2CxCONSET 0x0008 +#define PIC32_I2CxCONINV 0x000C +#define I2CCON_ON (1<<15) +#define I2CCON_FRZ (1<<14) +#define I2CCON_SIDL (1<<13) +#define I2CCON_SCLREL (1<<12) +#define I2CCON_STRICT (1<<11) +#define I2CCON_A10M (1<<10) +#define I2CCON_DISSLW (1<<9) +#define I2CCON_SMEN (1<<8) +#define I2CCON_GCEN (1<<7) +#define I2CCON_STREN (1<<6) +#define I2CCON_ACKDT (1<<5) +#define I2CCON_ACKEN (1<<4) +#define I2CCON_RCEN (1<<3) +#define I2CCON_PEN (1<<2) +#define I2CCON_RSEN (1<<1) +#define I2CCON_SEN (1<<0) + +#define PIC32_I2CxSTAT 0x0010 +#define PIC32_I2CxSTATCLR 0x0014 +#define PIC32_I2CxSTATSET 0x0018 +#define PIC32_I2CxSTATINV 0x001C +#define I2CSTAT_ACKSTAT (1<<15) +#define I2CSTAT_TRSTAT (1<<14) +#define I2CSTAT_BCL (1<<10) +#define I2CSTAT_GCSTAT (1<<9) +#define I2CSTAT_ADD10 (1<<8) +#define I2CSTAT_IWCOL (1<<7) +#define I2CSTAT_I2COV (1<<6) +#define I2CSTAT_DA (1<<5) +#define I2CSTAT_P (1<<4) +#define I2CSTAT_S (1<<3) +#define I2CSTAT_RW (1<<2) +#define I2CSTAT_RBF (1<<1) +#define I2CSTAT_TBF (1<<0) + +#define PIC32_I2CxADD 0x0020 +#define PIC32_I2CxADDCLR 0x0024 +#define PIC32_I2CxADDSET 0x0028 +#define PIC32_I2CxADDINV 0x002C +#define PIC32_I2CxMSK 0x0030 +#define PIC32_I2CxMSKCLR 0x0034 +#define PIC32_I2CxMSKSET 0x0038 +#define PIC32_I2CxMSKINV 0x003C +#define PIC32_I2CxBRG 0x0040 +#define PIC32_I2CxBRGCLR 0x0044 +#define PIC32_I2CxBRGSET 0x0048 +#define PIC32_I2CxBRGINV 0x004C +#define PIC32_I2CxTRN 0x0050 +#define PIC32_I2CxTRNCLR 0x0054 +#define PIC32_I2CxTRNSET 0x0058 +#define PIC32_I2CxTRNINV 0x005C +#define PIC32_I2CxRCV 0x0060 + +struct i2c_platform_data { + u32 base; + struct i2c_adapter adap; + u32 xfer_timeout; + u32 ack_timeout; + u32 ctl_timeout; +}; + +extern u32 pic32_bus_readl(u32 reg); +extern void pic32_bus_writel(u32 val, u32 reg); + +static inline void +StartI2C(struct i2c_platform_data *adap) +{ + pr_debug("StartI2C\n"); + pic32_bus_writel(I2CCON_SEN, adap->base + PIC32_I2CxCONSET); +} + +static inline void +StopI2C(struct i2c_platform_data *adap) +{ + pr_debug("StopI2C\n"); + pic32_bus_writel(I2CCON_PEN, adap->base + PIC32_I2CxCONSET); +} + +static inline void +AckI2C(struct i2c_platform_data *adap) +{ + pr_debug("AckI2C\n"); + pic32_bus_writel(I2CCON_ACKDT, adap->base + PIC32_I2CxCONCLR); + pic32_bus_writel(I2CCON_ACKEN, adap->base + PIC32_I2CxCONSET); +} + +static inline void +NotAckI2C(struct i2c_platform_data *adap) +{ + pr_debug("NakI2C\n"); + pic32_bus_writel(I2CCON_ACKDT, adap->base + PIC32_I2CxCONSET); + pic32_bus_writel(I2CCON_ACKEN, adap->base + PIC32_I2CxCONSET); +} + +static inline int +IdleI2C(struct i2c_platform_data *adap) +{ + int i; + + pr_debug("IdleI2C\n"); + for (i = 0; i < adap->ctl_timeout; i++) { + if (((pic32_bus_readl(adap->base + PIC32_I2CxCON) & + (I2CCON_ACKEN | I2CCON_RCEN | I2CCON_PEN | I2CCON_RSEN | + I2CCON_SEN)) == 0) && + ((pic32_bus_readl(adap->base + PIC32_I2CxSTAT) & + (I2CSTAT_TRSTAT)) == 0)) + return 0; + udelay(1); + } + return -ETIMEDOUT; +} + +static inline u32 +MasterWriteI2C(struct i2c_platform_data *adap, u32 byte) +{ + pr_debug("MasterWriteI2C\n"); + + pic32_bus_writel(byte, adap->base + PIC32_I2CxTRN); + + return pic32_bus_readl(adap->base + PIC32_I2CxSTAT) & I2CSTAT_IWCOL; +} + +static inline u32 +MasterReadI2C(struct i2c_platform_data *adap) +{ + pr_debug("MasterReadI2C\n"); + + pic32_bus_writel(I2CCON_RCEN, adap->base + PIC32_I2CxCONSET); + + while (pic32_bus_readl(adap->base + PIC32_I2CxCON) & I2CCON_RCEN) + ; + + pic32_bus_writel(I2CSTAT_I2COV, adap->base + PIC32_I2CxSTATCLR); + + return pic32_bus_readl(adap->base + PIC32_I2CxRCV); +} + +static int +do_address(struct i2c_platform_data *adap, unsigned int addr, int rd) +{ + pr_debug("doaddress\n"); + + IdleI2C(adap); + StartI2C(adap); + IdleI2C(adap); + + addr <<= 1; + if (rd) + addr |= 1; + + if (MasterWriteI2C(adap, addr)) + return -EIO; + IdleI2C(adap); + if (pic32_bus_readl(adap->base + PIC32_I2CxSTAT) & I2CSTAT_ACKSTAT) + return -EIO; + return 0; +} + +static int +i2c_read(struct i2c_platform_data *adap, unsigned char *buf, + unsigned int len) +{ + int i; + u32 data; + + pr_debug("i2c_read\n"); + + i = 0; + while (i < len) { + data = MasterReadI2C(adap); + buf[i++] = data; + if (i < len) + AckI2C(adap); + else + NotAckI2C(adap); + } + + StopI2C(adap); + IdleI2C(adap); + return 0; +} + +static int +i2c_write(struct i2c_platform_data *adap, unsigned char *buf, + unsigned int len) +{ + int i; + u32 data; + + pr_debug("i2c_write\n"); + + i = 0; + while (i < len) { + data = buf[i]; + if (MasterWriteI2C(adap, data)) + return -EIO; + IdleI2C(adap); + if (pic32_bus_readl(adap->base + PIC32_I2CxSTAT) & + I2CSTAT_ACKSTAT) + return -EIO; + i++; + } + + StopI2C(adap); + IdleI2C(adap); + return 0; +} + +static int +platform_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) +{ + struct i2c_platform_data *adap = i2c_adap->algo_data; + struct i2c_msg *p; + int i, err = 0; + + pr_debug("platform_xfer\n"); + for (i = 0; i < num; i++) { +#define __BUFSIZE 80 + int ii; + static char buf[__BUFSIZE]; + char *b = buf; + + p = &msgs[i]; + b += sprintf(buf, " [%d bytes]", p->len); + if ((p->flags & I2C_M_RD) == 0) { + for (ii = 0; ii < p->len; ii++) { + if (b < &buf[__BUFSIZE-4]) { + b += sprintf(b, " %02x", p->buf[ii]); + } else { + strcat(b, "..."); + break; + } + } + } + pr_debug("xfer%d: DevAddr: %04x Op:%s Data:%s\n", i, p->addr, + (p->flags & I2C_M_RD) ? "Rd" : "Wr", buf); + } + + + for (i = 0; !err && i < num; i++) { + p = &msgs[i]; + err = do_address(adap, p->addr, p->flags & I2C_M_RD); + if (err || !p->len) + continue; + if (p->flags & I2C_M_RD) + err = i2c_read(adap, p->buf, p->len); + else + err = i2c_write(adap, p->buf, p->len); + } + + /* Return the number of messages processed, or the error code. */ + if (err == 0) + err = num; + + return err; +} + +static u32 +platform_func(struct i2c_adapter *adap) +{ + pr_debug("platform_algo\n"); + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm platform_algo = { + .master_xfer = platform_xfer, + .functionality = platform_func, +}; + +static void i2c_platform_setup(struct i2c_platform_data *priv) +{ + pr_debug("i2c_platform_setup\n"); + + pic32_bus_writel(500, priv->base + PIC32_I2CxBRG); + pic32_bus_writel(I2CCON_ON, priv->base + PIC32_I2CxCONCLR); + pic32_bus_writel(I2CCON_ON, priv->base + PIC32_I2CxCONSET); + pic32_bus_writel((I2CSTAT_BCL | I2CSTAT_IWCOL), + (priv->base + PIC32_I2CxSTATCLR)); +} + +static void i2c_platform_disable(struct i2c_platform_data *priv) +{ + pr_debug("i2c_platform_disable\n"); +} + +static int __devinit +i2c_platform_probe(struct platform_device *pdev) +{ + struct i2c_platform_data *priv; + struct resource *r; + int ret; + + pr_debug("i2c_platform_probe\n"); + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!r) { + ret = -ENODEV; + goto out; + } + + priv = kzalloc(sizeof(struct i2c_platform_data), GFP_KERNEL); + if (!priv) { + ret = -ENOMEM; + goto out; + } + + /* FIXME: need to allocate resource in PIC32 space */ +#if 0 + priv->base = bus_request_region(r->start, resource_size(r), + pdev->name); +#else + priv->base = r->start; +#endif + if (!priv->base) { + ret = -EBUSY; + goto out_mem; + } + + priv->xfer_timeout = 200; + priv->ack_timeout = 200; + priv->ctl_timeout = 200; + + priv->adap.nr = pdev->id; + priv->adap.algo = &platform_algo; + priv->adap.algo_data = priv; + priv->adap.dev.parent = &pdev->dev; + strlcpy(priv->adap.name, "PIC32 I2C", sizeof(priv->adap.name)); + + i2c_platform_setup(priv); + + ret = i2c_add_numbered_adapter(&priv->adap); + if (ret == 0) { + platform_set_drvdata(pdev, priv); + return 0; + } + + i2c_platform_disable(priv); + +out_mem: + kfree(priv); +out: + return ret; +} + +static int __devexit +i2c_platform_remove(struct platform_device *pdev) +{ + struct i2c_platform_data *priv = platform_get_drvdata(pdev); + + pr_debug("i2c_platform_remove\n"); + platform_set_drvdata(pdev, NULL); + i2c_del_adapter(&priv->adap); + i2c_platform_disable(priv); + kfree(priv); + return 0; +} + +#ifdef CONFIG_PM +static int +i2c_platform_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct i2c_platform_data *priv = platform_get_drvdata(pdev); + + dev_dbg(&pdev->dev, "i2c_platform_disable\n"); + i2c_platform_disable(priv); + + return 0; +} + +static int +i2c_platform_resume(struct platform_device *pdev) +{ + struct i2c_platform_data *priv = platform_get_drvdata(pdev); + + dev_dbg(&pdev->dev, "i2c_platform_setup\n"); + i2c_platform_setup(priv); + + return 0; +} +#else +#define i2c_platform_suspend NULL +#define i2c_platform_resume NULL +#endif + +static struct platform_driver i2c_platform_driver = { + .driver = { + .name = "i2c_pic32", + .owner = THIS_MODULE, + }, + .probe = i2c_platform_probe, + .remove = __devexit_p(i2c_platform_remove), + .suspend = i2c_platform_suspend, + .resume = i2c_platform_resume, +}; + +static int __init +i2c_platform_init(void) +{ + pr_debug("i2c_platform_init\n"); + return platform_driver_register(&i2c_platform_driver); +} + +static void __exit +i2c_platform_exit(void) +{ + pr_debug("i2c_platform_exit\n"); + platform_driver_unregister(&i2c_platform_driver); +} + +MODULE_AUTHOR("Chris Dearman, MIPS Technologies INC."); +MODULE_DESCRIPTION("PIC32 I2C driver"); +MODULE_LICENSE("GPL"); + +module_init(i2c_platform_init); +module_exit(i2c_platform_exit); |