X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fi2c%2Fbusses%2Fi2c-ibm_iic.c;h=a25218dbac1e2a6b8c8fab198c2bb277792ae165;hb=9bf4aaab3e101692164d49b7ca357651eb691cb6;hp=35c7714786b4b1efe49ceb0e9c5ffbd22a507971;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c index 35c771478..a25218dba 100644 --- a/drivers/i2c/busses/i2c-ibm_iic.c +++ b/drivers/i2c/busses/i2c-ibm_iic.c @@ -3,7 +3,7 @@ * * Support for the IIC peripheral on IBM PPC 4xx * - * Copyright (c) 2003 Zultys Technologies. + * Copyright (c) 2003, 2004 Zultys Technologies. * Eugene Surovegin or * * Based on original work by @@ -45,7 +45,7 @@ #include "i2c-ibm_iic.h" -#define DRIVER_VERSION "2.0" +#define DRIVER_VERSION "2.1" MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION); MODULE_LICENSE("GPL"); @@ -69,14 +69,14 @@ MODULE_PARM_DESC(iic_fast_poll, "Force fast mode (400 kHz)"); #endif #if DBG_LEVEL > 0 -# define DBG(x...) printk(KERN_DEBUG "ibm-iic" ##x) +# define DBG(f,x...) printk(KERN_DEBUG "ibm-iic" f, ##x) #else -# define DBG(x...) ((void)0) +# define DBG(f,x...) ((void)0) #endif #if DBG_LEVEL > 1 -# define DBG2(x...) DBG( ##x ) +# define DBG2(f,x...) DBG(f, ##x) #else -# define DBG2(x...) ((void)0) +# define DBG2(f,x...) ((void)0) #endif #if DBG_LEVEL > 2 static void dump_iic_regs(const char* header, struct ibm_iic_private* dev) @@ -96,6 +96,31 @@ static void dump_iic_regs(const char* header, struct ibm_iic_private* dev) # define DUMP_REGS(h,dev) ((void)0) #endif +/* Bus timings (in ns) for bit-banging */ +static struct i2c_timings { + unsigned int hd_sta; + unsigned int su_sto; + unsigned int low; + unsigned int high; + unsigned int buf; +} timings [] = { +/* Standard mode (100 KHz) */ +{ + .hd_sta = 4000, + .su_sto = 4000, + .low = 4700, + .high = 4000, + .buf = 4700, +}, +/* Fast mode (400 KHz) */ +{ + .hd_sta = 600, + .su_sto = 600, + .low = 1300, + .high = 600, + .buf = 1300, +}}; + /* Enable/disable interrupt generation */ static inline void iic_interrupt_mode(struct ibm_iic_private* dev, int enable) { @@ -195,6 +220,104 @@ static void iic_dev_reset(struct ibm_iic_private* dev) iic_dev_init(dev); } +/* + * Do 0-length transaction using bit-banging through IIC_DIRECTCNTL register. + */ + +/* Wait for SCL and/or SDA to be high */ +static int iic_dc_wait(volatile struct iic_regs *iic, u8 mask) +{ + unsigned long x = jiffies + HZ / 28 + 2; + while ((in_8(&iic->directcntl) & mask) != mask){ + if (unlikely(time_after(jiffies, x))) + return -1; + cond_resched(); + } + return 0; +} + +static int iic_smbus_quick(struct ibm_iic_private* dev, const struct i2c_msg* p) +{ + volatile struct iic_regs* iic = dev->vaddr; + const struct i2c_timings* t = &timings[dev->fast_mode ? 1 : 0]; + u8 mask, v, sda; + int i, res; + + /* Only 7-bit addresses are supported */ + if (unlikely(p->flags & I2C_M_TEN)){ + DBG("%d: smbus_quick - 10 bit addresses are not supported\n", + dev->idx); + return -EINVAL; + } + + DBG("%d: smbus_quick(0x%02x)\n", dev->idx, p->addr); + + /* Reset IIC interface */ + out_8(&iic->xtcntlss, XTCNTLSS_SRST); + + /* Wait for bus to become free */ + out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC); + if (unlikely(iic_dc_wait(iic, DIRCNTL_MSDA | DIRCNTL_MSC))) + goto err; + ndelay(t->buf); + + /* START */ + out_8(&iic->directcntl, DIRCNTL_SCC); + sda = 0; + ndelay(t->hd_sta); + + /* Send address */ + v = (u8)((p->addr << 1) | ((p->flags & I2C_M_RD) ? 1 : 0)); + for (i = 0, mask = 0x80; i < 8; ++i, mask >>= 1){ + out_8(&iic->directcntl, sda); + ndelay(t->low / 2); + sda = (v & mask) ? DIRCNTL_SDAC : 0; + out_8(&iic->directcntl, sda); + ndelay(t->low / 2); + + out_8(&iic->directcntl, DIRCNTL_SCC | sda); + if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC))) + goto err; + ndelay(t->high); + } + + /* ACK */ + out_8(&iic->directcntl, sda); + ndelay(t->low / 2); + out_8(&iic->directcntl, DIRCNTL_SDAC); + ndelay(t->low / 2); + out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC); + if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC))) + goto err; + res = (in_8(&iic->directcntl) & DIRCNTL_MSDA) ? -EREMOTEIO : 1; + ndelay(t->high); + + /* STOP */ + out_8(&iic->directcntl, 0); + ndelay(t->low); + out_8(&iic->directcntl, DIRCNTL_SCC); + if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC))) + goto err; + ndelay(t->su_sto); + out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC); + + ndelay(t->buf); + + DBG("%d: smbus_quick -> %s\n", dev->idx, res ? "NACK" : "ACK"); +out: + /* Remove reset */ + out_8(&iic->xtcntlss, 0); + + /* Reinitialize interface */ + iic_dev_init(dev); + + return res; +err: + DBG("%d: smbus_quick - bus is stuck\n", dev->idx); + res = -EREMOTEIO; + goto out; +} + /* * IIC interrupt handler */ @@ -455,6 +578,13 @@ static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) } for (i = 0; i < num; ++i){ if (unlikely(msgs[i].len <= 0)){ + if (num == 1 && !msgs[0].len){ + /* Special case for I2C_SMBUS_QUICK emulation. + * IBM IIC doesn't support 0-length transactions + * so we have to emulate them using bit-banging. + */ + return iic_smbus_quick(dev, &msgs[0]); + } DBG("%d: invalid len %d in msg[%d]\n", dev->idx, msgs[i].len, i); return -EINVAL; @@ -549,19 +679,24 @@ static int __devinit iic_probe(struct ocp_device *ocp){ struct ibm_iic_private* dev; struct i2c_adapter* adap; + struct ocp_func_iic_data* iic_data = ocp->def->additions; int ret; - bd_t* bd = (bd_t*)&__res; + if (!iic_data) + printk(KERN_WARNING"ibm-iic%d: missing additional data!\n", + ocp->def->index); + if (!(dev = kmalloc(sizeof(*dev), GFP_KERNEL))){ - printk(KERN_CRIT "ibm-iic: failed to allocate device data\n"); + printk(KERN_CRIT "ibm-iic%d: failed to allocate device data\n", + ocp->def->index); return -ENOMEM; } memset(dev, 0, sizeof(*dev)); - dev->idx = ocp->num; + dev->idx = ocp->def->index; ocp_set_drvdata(ocp, dev); - if (!(dev->vaddr = ioremap(ocp->paddr, sizeof(struct iic_regs)))){ + if (!(dev->vaddr = ioremap(ocp->def->paddr, sizeof(struct iic_regs)))){ printk(KERN_CRIT "ibm-iic%d: failed to ioremap device registers\n", dev->idx); ret = -ENXIO; @@ -570,7 +705,7 @@ static int __devinit iic_probe(struct ocp_device *ocp){ init_waitqueue_head(&dev->wq); - dev->irq = iic_force_poll ? -1 : ocp->irq; + dev->irq = iic_force_poll ? -1 : ocp->def->irq; if (dev->irq >= 0){ /* Disable interrupts until we finish intialization, assumes level-sensitive IRQ setup... @@ -589,13 +724,12 @@ static int __devinit iic_probe(struct ocp_device *ocp){ dev->idx); /* Board specific settings */ - BUG_ON(dev->idx >= sizeof(bd->bi_iic_fast) / sizeof(bd->bi_iic_fast[0])); - dev->fast_mode = iic_force_fast ? 1 : bd->bi_iic_fast[dev->idx]; + dev->fast_mode = iic_force_fast ? 1 : (iic_data ? iic_data->fast_mode : 0); /* clckdiv is the same for *all* IIC interfaces, * but I'd rather make a copy than introduce another global. --ebs */ - dev->clckdiv = iic_clckdiv(bd->bi_opb_busfreq); + dev->clckdiv = iic_clckdiv(ocp_sys_info.opb_bus_freq); DBG("%d: clckdiv = %d\n", dev->idx, dev->clckdiv); /* Initialize IIC interface */ @@ -664,7 +798,7 @@ static void __devexit iic_remove(struct ocp_device *ocp) static struct ocp_device_id ibm_iic_ids[] __devinitdata = { - { .vendor = OCP_VENDOR_IBM, .device = OCP_FUNC_IIC }, + { .vendor = OCP_VENDOR_IBM, .function = OCP_FUNC_IIC }, { .vendor = OCP_VENDOR_INVALID } }; @@ -672,7 +806,7 @@ MODULE_DEVICE_TABLE(ocp, ibm_iic_ids); static struct ocp_driver ibm_iic_driver = { - .name = "ocp_iic", + .name = "iic", .id_table = ibm_iic_ids, .probe = iic_probe, .remove = __devexit_p(iic_remove), @@ -685,7 +819,7 @@ static struct ocp_driver ibm_iic_driver = static int __init iic_init(void) { printk(KERN_INFO "IBM IIC driver v" DRIVER_VERSION "\n"); - return ocp_module_init(&ibm_iic_driver); + return ocp_register_driver(&ibm_iic_driver); } static void __exit iic_exit(void)