| /* |
| * drivers/i2c/busses/i2c-ibm_iic.c |
| * |
| * Support for the IIC peripheral on IBM PPC 4xx |
| * |
| * Copyright (c) 2003, 2004 Zultys Technologies. |
| * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net> |
| * |
| * Copyright (c) 2008 PIKA Technologies |
| * Sean MacLennan <smaclennan@pikatech.com> |
| * |
| * Based on original work by |
| * Ian DaSilva <idasilva@mvista.com> |
| * Armin Kuster <akuster@mvista.com> |
| * Matt Porter <mporter@mvista.com> |
| * |
| * Copyright 2000-2003 MontaVista Software Inc. |
| * |
| * Original driver version was highly leveraged from i2c-elektor.c |
| * |
| * Copyright 1995-97 Simon G. Vogl |
| * 1998-99 Hans Berglund |
| * |
| * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> |
| * and even Frodo Looijaard <frodol@dds.nl> |
| * |
| * 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. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/ioport.h> |
| #include <linux/delay.h> |
| #include <linux/slab.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <asm/irq.h> |
| #include <asm/io.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c-id.h> |
| #include <linux/of_platform.h> |
| #include <linux/of_i2c.h> |
| |
| #include "i2c-ibm_iic.h" |
| |
| #define DRIVER_VERSION "2.2" |
| |
| MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION); |
| MODULE_LICENSE("GPL"); |
| |
| static int iic_force_poll; |
| module_param(iic_force_poll, bool, 0); |
| MODULE_PARM_DESC(iic_force_poll, "Force polling mode"); |
| |
| static int iic_force_fast; |
| module_param(iic_force_fast, bool, 0); |
| MODULE_PARM_DESC(iic_force_fast, "Force fast mode (400 kHz)"); |
| |
| #define DBG_LEVEL 0 |
| |
| #ifdef DBG |
| #undef DBG |
| #endif |
| |
| #ifdef DBG2 |
| #undef DBG2 |
| #endif |
| |
| #if DBG_LEVEL > 0 |
| # define DBG(f,x...) printk(KERN_DEBUG "ibm-iic" f, ##x) |
| #else |
| # define DBG(f,x...) ((void)0) |
| #endif |
| #if DBG_LEVEL > 1 |
| # define DBG2(f,x...) DBG(f, ##x) |
| #else |
| # define DBG2(f,x...) ((void)0) |
| #endif |
| #if DBG_LEVEL > 2 |
| static void dump_iic_regs(const char* header, struct ibm_iic_private* dev) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| printk(KERN_DEBUG "ibm-iic%d: %s\n", dev->idx, header); |
| printk(KERN_DEBUG " cntl = 0x%02x, mdcntl = 0x%02x\n" |
| KERN_DEBUG " sts = 0x%02x, extsts = 0x%02x\n" |
| KERN_DEBUG " clkdiv = 0x%02x, xfrcnt = 0x%02x\n" |
| KERN_DEBUG " xtcntlss = 0x%02x, directcntl = 0x%02x\n", |
| in_8(&iic->cntl), in_8(&iic->mdcntl), in_8(&iic->sts), |
| in_8(&iic->extsts), in_8(&iic->clkdiv), in_8(&iic->xfrcnt), |
| in_8(&iic->xtcntlss), in_8(&iic->directcntl)); |
| } |
| # define DUMP_REGS(h,dev) dump_iic_regs((h),(dev)) |
| #else |
| # 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) |
| { |
| out_8(&dev->vaddr->intmsk, enable ? INTRMSK_EIMTC : 0); |
| } |
| |
| /* |
| * Initialize IIC interface. |
| */ |
| static void iic_dev_init(struct ibm_iic_private* dev) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| |
| DBG("%d: init\n", dev->idx); |
| |
| /* Clear master address */ |
| out_8(&iic->lmadr, 0); |
| out_8(&iic->hmadr, 0); |
| |
| /* Clear slave address */ |
| out_8(&iic->lsadr, 0); |
| out_8(&iic->hsadr, 0); |
| |
| /* Clear status & extended status */ |
| out_8(&iic->sts, STS_SCMP | STS_IRQA); |
| out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD | EXTSTS_LA |
| | EXTSTS_ICT | EXTSTS_XFRA); |
| |
| /* Set clock divider */ |
| out_8(&iic->clkdiv, dev->clckdiv); |
| |
| /* Clear transfer count */ |
| out_8(&iic->xfrcnt, 0); |
| |
| /* Clear extended control and status */ |
| out_8(&iic->xtcntlss, XTCNTLSS_SRC | XTCNTLSS_SRS | XTCNTLSS_SWC |
| | XTCNTLSS_SWS); |
| |
| /* Clear control register */ |
| out_8(&iic->cntl, 0); |
| |
| /* Enable interrupts if possible */ |
| iic_interrupt_mode(dev, dev->irq >= 0); |
| |
| /* Set mode control */ |
| out_8(&iic->mdcntl, MDCNTL_FMDB | MDCNTL_EINT | MDCNTL_EUBS |
| | (dev->fast_mode ? MDCNTL_FSM : 0)); |
| |
| DUMP_REGS("iic_init", dev); |
| } |
| |
| /* |
| * Reset IIC interface |
| */ |
| static void iic_dev_reset(struct ibm_iic_private* dev) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| int i; |
| u8 dc; |
| |
| DBG("%d: soft reset\n", dev->idx); |
| DUMP_REGS("reset", dev); |
| |
| /* Place chip in the reset state */ |
| out_8(&iic->xtcntlss, XTCNTLSS_SRST); |
| |
| /* Check if bus is free */ |
| dc = in_8(&iic->directcntl); |
| if (!DIRCTNL_FREE(dc)){ |
| DBG("%d: trying to regain bus control\n", dev->idx); |
| |
| /* Try to set bus free state */ |
| out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC); |
| |
| /* Wait until we regain bus control */ |
| for (i = 0; i < 100; ++i){ |
| dc = in_8(&iic->directcntl); |
| if (DIRCTNL_FREE(dc)) |
| break; |
| |
| /* Toggle SCL line */ |
| dc ^= DIRCNTL_SCC; |
| out_8(&iic->directcntl, dc); |
| udelay(10); |
| dc ^= DIRCNTL_SCC; |
| out_8(&iic->directcntl, dc); |
| |
| /* be nice */ |
| cond_resched(); |
| } |
| } |
| |
| /* Remove reset */ |
| out_8(&iic->xtcntlss, 0); |
| |
| /* Reinitialize interface */ |
| 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 __iomem *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 __iomem *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 |
| */ |
| static irqreturn_t iic_handler(int irq, void *dev_id) |
| { |
| struct ibm_iic_private* dev = (struct ibm_iic_private*)dev_id; |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| |
| DBG2("%d: irq handler, STS = 0x%02x, EXTSTS = 0x%02x\n", |
| dev->idx, in_8(&iic->sts), in_8(&iic->extsts)); |
| |
| /* Acknowledge IRQ and wakeup iic_wait_for_tc */ |
| out_8(&iic->sts, STS_IRQA | STS_SCMP); |
| wake_up_interruptible(&dev->wq); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* |
| * Get master transfer result and clear errors if any. |
| * Returns the number of actually transferred bytes or error (<0) |
| */ |
| static int iic_xfer_result(struct ibm_iic_private* dev) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| |
| if (unlikely(in_8(&iic->sts) & STS_ERR)){ |
| DBG("%d: xfer error, EXTSTS = 0x%02x\n", dev->idx, |
| in_8(&iic->extsts)); |
| |
| /* Clear errors and possible pending IRQs */ |
| out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD | |
| EXTSTS_LA | EXTSTS_ICT | EXTSTS_XFRA); |
| |
| /* Flush master data buffer */ |
| out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB); |
| |
| /* Is bus free? |
| * If error happened during combined xfer |
| * IIC interface is usually stuck in some strange |
| * state, the only way out - soft reset. |
| */ |
| if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){ |
| DBG("%d: bus is stuck, resetting\n", dev->idx); |
| iic_dev_reset(dev); |
| } |
| return -EREMOTEIO; |
| } |
| else |
| return in_8(&iic->xfrcnt) & XFRCNT_MTC_MASK; |
| } |
| |
| /* |
| * Try to abort active transfer. |
| */ |
| static void iic_abort_xfer(struct ibm_iic_private* dev) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| unsigned long x; |
| |
| DBG("%d: iic_abort_xfer\n", dev->idx); |
| |
| out_8(&iic->cntl, CNTL_HMT); |
| |
| /* |
| * Wait for the abort command to complete. |
| * It's not worth to be optimized, just poll (timeout >= 1 tick) |
| */ |
| x = jiffies + 2; |
| while ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){ |
| if (time_after(jiffies, x)){ |
| DBG("%d: abort timeout, resetting...\n", dev->idx); |
| iic_dev_reset(dev); |
| return; |
| } |
| schedule(); |
| } |
| |
| /* Just to clear errors */ |
| iic_xfer_result(dev); |
| } |
| |
| /* |
| * Wait for master transfer to complete. |
| * It puts current process to sleep until we get interrupt or timeout expires. |
| * Returns the number of transferred bytes or error (<0) |
| */ |
| static int iic_wait_for_tc(struct ibm_iic_private* dev){ |
| |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| int ret = 0; |
| |
| if (dev->irq >= 0){ |
| /* Interrupt mode */ |
| ret = wait_event_interruptible_timeout(dev->wq, |
| !(in_8(&iic->sts) & STS_PT), dev->adap.timeout); |
| |
| if (unlikely(ret < 0)) |
| DBG("%d: wait interrupted\n", dev->idx); |
| else if (unlikely(in_8(&iic->sts) & STS_PT)){ |
| DBG("%d: wait timeout\n", dev->idx); |
| ret = -ETIMEDOUT; |
| } |
| } |
| else { |
| /* Polling mode */ |
| unsigned long x = jiffies + dev->adap.timeout; |
| |
| while (in_8(&iic->sts) & STS_PT){ |
| if (unlikely(time_after(jiffies, x))){ |
| DBG("%d: poll timeout\n", dev->idx); |
| ret = -ETIMEDOUT; |
| break; |
| } |
| |
| if (unlikely(signal_pending(current))){ |
| DBG("%d: poll interrupted\n", dev->idx); |
| ret = -ERESTARTSYS; |
| break; |
| } |
| schedule(); |
| } |
| } |
| |
| if (unlikely(ret < 0)) |
| iic_abort_xfer(dev); |
| else |
| ret = iic_xfer_result(dev); |
| |
| DBG2("%d: iic_wait_for_tc -> %d\n", dev->idx, ret); |
| |
| return ret; |
| } |
| |
| /* |
| * Low level master transfer routine |
| */ |
| static int iic_xfer_bytes(struct ibm_iic_private* dev, struct i2c_msg* pm, |
| int combined_xfer) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| char* buf = pm->buf; |
| int i, j, loops, ret = 0; |
| int len = pm->len; |
| |
| u8 cntl = (in_8(&iic->cntl) & CNTL_AMD) | CNTL_PT; |
| if (pm->flags & I2C_M_RD) |
| cntl |= CNTL_RW; |
| |
| loops = (len + 3) / 4; |
| for (i = 0; i < loops; ++i, len -= 4){ |
| int count = len > 4 ? 4 : len; |
| u8 cmd = cntl | ((count - 1) << CNTL_TCT_SHIFT); |
| |
| if (!(cntl & CNTL_RW)) |
| for (j = 0; j < count; ++j) |
| out_8((void __iomem *)&iic->mdbuf, *buf++); |
| |
| if (i < loops - 1) |
| cmd |= CNTL_CHT; |
| else if (combined_xfer) |
| cmd |= CNTL_RPST; |
| |
| DBG2("%d: xfer_bytes, %d, CNTL = 0x%02x\n", dev->idx, count, cmd); |
| |
| /* Start transfer */ |
| out_8(&iic->cntl, cmd); |
| |
| /* Wait for completion */ |
| ret = iic_wait_for_tc(dev); |
| |
| if (unlikely(ret < 0)) |
| break; |
| else if (unlikely(ret != count)){ |
| DBG("%d: xfer_bytes, requested %d, transfered %d\n", |
| dev->idx, count, ret); |
| |
| /* If it's not a last part of xfer, abort it */ |
| if (combined_xfer || (i < loops - 1)) |
| iic_abort_xfer(dev); |
| |
| ret = -EREMOTEIO; |
| break; |
| } |
| |
| if (cntl & CNTL_RW) |
| for (j = 0; j < count; ++j) |
| *buf++ = in_8((void __iomem *)&iic->mdbuf); |
| } |
| |
| return ret > 0 ? 0 : ret; |
| } |
| |
| /* |
| * Set target slave address for master transfer |
| */ |
| static inline void iic_address(struct ibm_iic_private* dev, struct i2c_msg* msg) |
| { |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| u16 addr = msg->addr; |
| |
| DBG2("%d: iic_address, 0x%03x (%d-bit)\n", dev->idx, |
| addr, msg->flags & I2C_M_TEN ? 10 : 7); |
| |
| if (msg->flags & I2C_M_TEN){ |
| out_8(&iic->cntl, CNTL_AMD); |
| out_8(&iic->lmadr, addr); |
| out_8(&iic->hmadr, 0xf0 | ((addr >> 7) & 0x06)); |
| } |
| else { |
| out_8(&iic->cntl, 0); |
| out_8(&iic->lmadr, addr << 1); |
| } |
| } |
| |
| static inline int iic_invalid_address(const struct i2c_msg* p) |
| { |
| return (p->addr > 0x3ff) || (!(p->flags & I2C_M_TEN) && (p->addr > 0x7f)); |
| } |
| |
| static inline int iic_address_neq(const struct i2c_msg* p1, |
| const struct i2c_msg* p2) |
| { |
| return (p1->addr != p2->addr) |
| || ((p1->flags & I2C_M_TEN) != (p2->flags & I2C_M_TEN)); |
| } |
| |
| /* |
| * Generic master transfer entrypoint. |
| * Returns the number of processed messages or error (<0) |
| */ |
| static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
| { |
| struct ibm_iic_private* dev = (struct ibm_iic_private*)(i2c_get_adapdata(adap)); |
| volatile struct iic_regs __iomem *iic = dev->vaddr; |
| int i, ret = 0; |
| |
| DBG2("%d: iic_xfer, %d msg(s)\n", dev->idx, num); |
| |
| if (!num) |
| return 0; |
| |
| /* Check the sanity of the passed messages. |
| * Uhh, generic i2c layer is more suitable place for such code... |
| */ |
| if (unlikely(iic_invalid_address(&msgs[0]))){ |
| DBG("%d: invalid address 0x%03x (%d-bit)\n", dev->idx, |
| msgs[0].addr, msgs[0].flags & I2C_M_TEN ? 10 : 7); |
| return -EINVAL; |
| } |
| 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; |
| } |
| if (unlikely(iic_address_neq(&msgs[0], &msgs[i]))){ |
| DBG("%d: invalid addr in msg[%d]\n", dev->idx, i); |
| return -EINVAL; |
| } |
| } |
| |
| /* Check bus state */ |
| if (unlikely((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE)){ |
| DBG("%d: iic_xfer, bus is not free\n", dev->idx); |
| |
| /* Usually it means something serious has happend. |
| * We *cannot* have unfinished previous transfer |
| * so it doesn't make any sense to try to stop it. |
| * Probably we were not able to recover from the |
| * previous error. |
| * The only *reasonable* thing I can think of here |
| * is soft reset. --ebs |
| */ |
| iic_dev_reset(dev); |
| |
| if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){ |
| DBG("%d: iic_xfer, bus is still not free\n", dev->idx); |
| return -EREMOTEIO; |
| } |
| } |
| else { |
| /* Flush master data buffer (just in case) */ |
| out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB); |
| } |
| |
| /* Load slave address */ |
| iic_address(dev, &msgs[0]); |
| |
| /* Do real transfer */ |
| for (i = 0; i < num && !ret; ++i) |
| ret = iic_xfer_bytes(dev, &msgs[i], i < num - 1); |
| |
| return ret < 0 ? ret : num; |
| } |
| |
| static u32 iic_func(struct i2c_adapter *adap) |
| { |
| return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR; |
| } |
| |
| static const struct i2c_algorithm iic_algo = { |
| .master_xfer = iic_xfer, |
| .functionality = iic_func |
| }; |
| |
| /* |
| * Calculates IICx_CLCKDIV value for a specific OPB clock frequency |
| */ |
| static inline u8 iic_clckdiv(unsigned int opb) |
| { |
| /* Compatibility kludge, should go away after all cards |
| * are fixed to fill correct value for opbfreq. |
| * Previous driver version used hardcoded divider value 4, |
| * it corresponds to OPB frequency from the range (40, 50] MHz |
| */ |
| if (!opb){ |
| printk(KERN_WARNING "ibm-iic: using compatibility value for OPB freq," |
| " fix your board specific setup\n"); |
| opb = 50000000; |
| } |
| |
| /* Convert to MHz */ |
| opb /= 1000000; |
| |
| if (opb < 20 || opb > 150){ |
| printk(KERN_WARNING "ibm-iic: invalid OPB clock frequency %u MHz\n", |
| opb); |
| opb = opb < 20 ? 20 : 150; |
| } |
| return (u8)((opb + 9) / 10 - 1); |
| } |
| |
| static int __devinit iic_request_irq(struct of_device *ofdev, |
| struct ibm_iic_private *dev) |
| { |
| struct device_node *np = ofdev->node; |
| int irq; |
| |
| if (iic_force_poll) |
| return NO_IRQ; |
| |
| irq = irq_of_parse_and_map(np, 0); |
| if (irq == NO_IRQ) { |
| dev_err(&ofdev->dev, "irq_of_parse_and_map failed\n"); |
| return NO_IRQ; |
| } |
| |
| /* Disable interrupts until we finish initialization, assumes |
| * level-sensitive IRQ setup... |
| */ |
| iic_interrupt_mode(dev, 0); |
| if (request_irq(irq, iic_handler, 0, "IBM IIC", dev)) { |
| dev_err(&ofdev->dev, "request_irq %d failed\n", irq); |
| /* Fallback to the polling mode */ |
| return NO_IRQ; |
| } |
| |
| return irq; |
| } |
| |
| /* |
| * Register single IIC interface |
| */ |
| static int __devinit iic_probe(struct of_device *ofdev, |
| const struct of_device_id *match) |
| { |
| struct device_node *np = ofdev->node; |
| struct ibm_iic_private *dev; |
| struct i2c_adapter *adap; |
| const u32 *freq; |
| int ret; |
| |
| dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
| if (!dev) { |
| dev_err(&ofdev->dev, "failed to allocate device data\n"); |
| return -ENOMEM; |
| } |
| |
| dev_set_drvdata(&ofdev->dev, dev); |
| |
| dev->vaddr = of_iomap(np, 0); |
| if (dev->vaddr == NULL) { |
| dev_err(&ofdev->dev, "failed to iomap device\n"); |
| ret = -ENXIO; |
| goto error_cleanup; |
| } |
| |
| init_waitqueue_head(&dev->wq); |
| |
| dev->irq = iic_request_irq(ofdev, dev); |
| if (dev->irq == NO_IRQ) |
| dev_warn(&ofdev->dev, "using polling mode\n"); |
| |
| /* Board specific settings */ |
| if (iic_force_fast || of_get_property(np, "fast-mode", NULL)) |
| dev->fast_mode = 1; |
| |
| freq = of_get_property(np, "clock-frequency", NULL); |
| if (freq == NULL) { |
| freq = of_get_property(np->parent, "clock-frequency", NULL); |
| if (freq == NULL) { |
| dev_err(&ofdev->dev, "Unable to get bus frequency\n"); |
| ret = -EINVAL; |
| goto error_cleanup; |
| } |
| } |
| |
| dev->clckdiv = iic_clckdiv(*freq); |
| dev_dbg(&ofdev->dev, "clckdiv = %d\n", dev->clckdiv); |
| |
| /* Initialize IIC interface */ |
| iic_dev_init(dev); |
| |
| /* Register it with i2c layer */ |
| adap = &dev->adap; |
| adap->dev.parent = &ofdev->dev; |
| strlcpy(adap->name, "IBM IIC", sizeof(adap->name)); |
| i2c_set_adapdata(adap, dev); |
| adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; |
| adap->algo = &iic_algo; |
| adap->timeout = HZ; |
| |
| ret = i2c_add_adapter(adap); |
| if (ret < 0) { |
| dev_err(&ofdev->dev, "failed to register i2c adapter\n"); |
| goto error_cleanup; |
| } |
| |
| /* Now register all the child nodes */ |
| of_register_i2c_devices(adap, np); |
| |
| dev_info(&ofdev->dev, "using %s mode\n", |
| dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)"); |
| |
| return 0; |
| |
| error_cleanup: |
| if (dev->irq != NO_IRQ) { |
| iic_interrupt_mode(dev, 0); |
| free_irq(dev->irq, dev); |
| } |
| |
| if (dev->vaddr) |
| iounmap(dev->vaddr); |
| |
| dev_set_drvdata(&ofdev->dev, NULL); |
| kfree(dev); |
| return ret; |
| } |
| |
| /* |
| * Cleanup initialized IIC interface |
| */ |
| static int __devexit iic_remove(struct of_device *ofdev) |
| { |
| struct ibm_iic_private *dev = dev_get_drvdata(&ofdev->dev); |
| |
| dev_set_drvdata(&ofdev->dev, NULL); |
| |
| i2c_del_adapter(&dev->adap); |
| |
| if (dev->irq != NO_IRQ) { |
| iic_interrupt_mode(dev, 0); |
| free_irq(dev->irq, dev); |
| } |
| |
| iounmap(dev->vaddr); |
| kfree(dev); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id ibm_iic_match[] = { |
| { .compatible = "ibm,iic", }, |
| {} |
| }; |
| |
| static struct of_platform_driver ibm_iic_driver = { |
| .name = "ibm-iic", |
| .match_table = ibm_iic_match, |
| .probe = iic_probe, |
| .remove = __devexit_p(iic_remove), |
| }; |
| |
| static int __init iic_init(void) |
| { |
| return of_register_platform_driver(&ibm_iic_driver); |
| } |
| |
| static void __exit iic_exit(void) |
| { |
| of_unregister_platform_driver(&ibm_iic_driver); |
| } |
| |
| module_init(iic_init); |
| module_exit(iic_exit); |