/* * Copyright (C) 2009 ST-Ericsson SA * Copyright (C) 2009 STMicroelectronics * * I2C master mode controller driver, used in Nomadik 8815 * and Ux500 platforms. * * Author: Srinidhi Kasagar * Author: Sachin Verma * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "nmk-i2c" /* I2C Controller register offsets */ #define I2C_CR (0x000) #define I2C_SCR (0x004) #define I2C_HSMCR (0x008) #define I2C_MCR (0x00C) #define I2C_TFR (0x010) #define I2C_SR (0x014) #define I2C_RFR (0x018) #define I2C_TFTR (0x01C) #define I2C_RFTR (0x020) #define I2C_DMAR (0x024) #define I2C_BRCR (0x028) #define I2C_IMSCR (0x02C) #define I2C_RISR (0x030) #define I2C_MISR (0x034) #define I2C_ICR (0x038) /* Control registers */ #define I2C_CR_PE (0x1 << 0) /* Peripheral Enable */ #define I2C_CR_OM (0x3 << 1) /* Operating mode */ #define I2C_CR_SAM (0x1 << 3) /* Slave addressing mode */ #define I2C_CR_SM (0x3 << 4) /* Speed mode */ #define I2C_CR_SGCM (0x1 << 6) /* Slave general call mode */ #define I2C_CR_FTX (0x1 << 7) /* Flush Transmit */ #define I2C_CR_FRX (0x1 << 8) /* Flush Receive */ #define I2C_CR_DMA_TX_EN (0x1 << 9) /* DMA Tx enable */ #define I2C_CR_DMA_RX_EN (0x1 << 10) /* DMA Rx Enable */ #define I2C_CR_DMA_SLE (0x1 << 11) /* DMA sync. logic enable */ #define I2C_CR_LM (0x1 << 12) /* Loopback mode */ #define I2C_CR_FON (0x3 << 13) /* Filtering on */ #define I2C_CR_FS (0x3 << 15) /* Force stop enable */ /* Master controller (MCR) register */ #define I2C_MCR_OP (0x1 << 0) /* Operation */ #define I2C_MCR_A7 (0x7f << 1) /* 7-bit address */ #define I2C_MCR_EA10 (0x7 << 8) /* 10-bit Extended address */ #define I2C_MCR_SB (0x1 << 11) /* Extended address */ #define I2C_MCR_AM (0x3 << 12) /* Address type */ #define I2C_MCR_STOP (0x1 << 14) /* Stop condition */ #define I2C_MCR_LENGTH (0x7ff << 15) /* Transaction length */ /* Status register (SR) */ #define I2C_SR_OP (0x3 << 0) /* Operation */ #define I2C_SR_STATUS (0x3 << 2) /* controller status */ #define I2C_SR_CAUSE (0x7 << 4) /* Abort cause */ #define I2C_SR_TYPE (0x3 << 7) /* Receive type */ #define I2C_SR_LENGTH (0x7ff << 9) /* Transfer length */ /* Interrupt mask set/clear (IMSCR) bits */ #define I2C_IT_TXFE (0x1 << 0) #define I2C_IT_TXFNE (0x1 << 1) #define I2C_IT_TXFF (0x1 << 2) #define I2C_IT_TXFOVR (0x1 << 3) #define I2C_IT_RXFE (0x1 << 4) #define I2C_IT_RXFNF (0x1 << 5) #define I2C_IT_RXFF (0x1 << 6) #define I2C_IT_RFSR (0x1 << 16) #define I2C_IT_RFSE (0x1 << 17) #define I2C_IT_WTSR (0x1 << 18) #define I2C_IT_MTD (0x1 << 19) #define I2C_IT_STD (0x1 << 20) #define I2C_IT_MAL (0x1 << 24) #define I2C_IT_BERR (0x1 << 25) #define I2C_IT_MTDWS (0x1 << 28) #define GEN_MASK(val, mask, sb) (((val) << (sb)) & (mask)) /* some bits in ICR are reserved */ #define I2C_CLEAR_ALL_INTS 0x131f007f /* first three msb bits are reserved */ #define IRQ_MASK(mask) (mask & 0x1fffffff) /* maximum threshold value */ #define MAX_I2C_FIFO_THRESHOLD 15 enum i2c_status { I2C_NOP, I2C_ON_GOING, I2C_OK, I2C_ABORT }; /* operation */ enum i2c_operation { I2C_NO_OPERATION = 0xff, I2C_WRITE = 0x00, I2C_READ = 0x01 }; /* controller response timeout in ms */ #define I2C_TIMEOUT_MS 500 /** * struct i2c_nmk_client - client specific data * @slave_adr: 7-bit slave address * @count: no. bytes to be transfered * @buffer: client data buffer * @xfer_bytes: bytes transfered till now * @operation: current I2C operation */ struct i2c_nmk_client { unsigned short slave_adr; unsigned long count; unsigned char *buffer; unsigned long xfer_bytes; enum i2c_operation operation; }; /** * struct nmk_i2c_dev - private data structure of the controller * @pdev: parent platform device * @adap: corresponding I2C adapter * @irq: interrupt line for the controller * @virtbase: virtual io memory area * @clk: hardware i2c block clock * @cfg: machine provided controller configuration * @cli: holder of client specific data * @stop: stop condition * @xfer_complete: acknowledge completion for a I2C message * @result: controller propogated result */ struct nmk_i2c_dev { struct platform_device *pdev; struct i2c_adapter adap; int irq; void __iomem *virtbase; struct clk *clk; struct nmk_i2c_controller cfg; struct i2c_nmk_client cli; int stop; struct completion xfer_complete; int result; }; /* controller's abort causes */ static const char *abort_causes[] = { "no ack received after address transmission", "no ack received during data phase", "ack received after xmission of master code", "master lost arbitration", "slave restarts", "slave reset", "overflow, maxsize is 2047 bytes", }; static inline void i2c_set_bit(void __iomem *reg, u32 mask) { writel(readl(reg) | mask, reg); } static inline void i2c_clr_bit(void __iomem *reg, u32 mask) { writel(readl(reg) & ~mask, reg); } /** * flush_i2c_fifo() - This function flushes the I2C FIFO * @dev: private data of I2C Driver * * This function flushes the I2C Tx and Rx FIFOs. It returns * 0 on successful flushing of FIFO */ static int flush_i2c_fifo(struct nmk_i2c_dev *dev) { #define LOOP_ATTEMPTS 10 int i; unsigned long timeout; /* * flush the transmit and receive FIFO. The flushing * operation takes several cycles before to be completed. * On the completion, the I2C internal logic clears these * bits, until then no one must access Tx, Rx FIFO and * should poll on these bits waiting for the completion. */ writel((I2C_CR_FTX | I2C_CR_FRX), dev->virtbase + I2C_CR); for (i = 0; i < LOOP_ATTEMPTS; i++) { timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT_MS); while (!time_after(jiffies, timeout)) { if ((readl(dev->virtbase + I2C_CR) & (I2C_CR_FTX | I2C_CR_FRX)) == 0) return 0; } } dev_err(&dev->pdev->dev, "flushing operation timed out " "giving up after %d attempts", LOOP_ATTEMPTS); return -ETIMEDOUT; } /** * disable_all_interrupts() - Disable all interrupts of this I2c Bus * @dev: private data of I2C Driver */ static void disable_all_interrupts(struct nmk_i2c_dev *dev) { u32 mask = IRQ_MASK(0); writel(mask, dev->virtbase + I2C_IMSCR); } /** * clear_all_interrupts() - Clear all interrupts of I2C Controller * @dev: private data of I2C Driver */ static void clear_all_interrupts(struct nmk_i2c_dev *dev) { u32 mask; mask = IRQ_MASK(I2C_CLEAR_ALL_INTS); writel(mask, dev->virtbase + I2C_ICR); } /** * init_hw() - initialize the I2C hardware * @dev: private data of I2C Driver */ static int init_hw(struct nmk_i2c_dev *dev) { int stat; stat = flush_i2c_fifo(dev); if (stat) return stat; /* disable the controller */ i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE); disable_all_interrupts(dev); clear_all_interrupts(dev); dev->cli.operation = I2C_NO_OPERATION; return 0; } /* enable peripheral, master mode operation */ #define DEFAULT_I2C_REG_CR ((1 << 1) | I2C_CR_PE) /** * load_i2c_mcr_reg() - load the MCR register * @dev: private data of controller */ static u32 load_i2c_mcr_reg(struct nmk_i2c_dev *dev) { u32 mcr = 0; /* 7-bit address transaction */ mcr |= GEN_MASK(1, I2C_MCR_AM, 12); mcr |= GEN_MASK(dev->cli.slave_adr, I2C_MCR_A7, 1); /* start byte procedure not applied */ mcr |= GEN_MASK(0, I2C_MCR_SB, 11); /* check the operation, master read/write? */ if (dev->cli.operation == I2C_WRITE) mcr |= GEN_MASK(I2C_WRITE, I2C_MCR_OP, 0); else mcr |= GEN_MASK(I2C_READ, I2C_MCR_OP, 0); /* stop or repeated start? */ if (dev->stop) mcr |= GEN_MASK(1, I2C_MCR_STOP, 14); else mcr &= ~(GEN_MASK(1, I2C_MCR_STOP, 14)); mcr |= GEN_MASK(dev->cli.count, I2C_MCR_LENGTH, 15); return mcr; } /** * setup_i2c_controller() - setup the controller * @dev: private data of controller */ static void setup_i2c_controller(struct nmk_i2c_dev *dev) { u32 brcr1, brcr2; u32 i2c_clk, div; writel(0x0, dev->virtbase + I2C_CR); writel(0x0, dev->virtbase + I2C_HSMCR); writel(0x0, dev->virtbase + I2C_TFTR); writel(0x0, dev->virtbase + I2C_RFTR); writel(0x0, dev->virtbase + I2C_DMAR); /* * set the slsu: * * slsu defines the data setup time after SCL clock * stretching in terms of i2c clk cycles. The * needed setup time for the three modes are 250ns, * 100ns, 10ns repectively thus leading to the values * of 14, 6, 2 for a 48 MHz i2c clk. */ writel(dev->cfg.slsu << 16, dev->virtbase + I2C_SCR); i2c_clk = clk_get_rate(dev->clk); /* fallback to std. mode if machine has not provided it */ if (dev->cfg.clk_freq == 0) dev->cfg.clk_freq = 100000; /* * The spec says, in case of std. mode the divider is * 2 whereas it is 3 for fast and fastplus mode of * operation. TODO - high speed support. */ div = (dev->cfg.clk_freq > 100000) ? 3 : 2; /* * generate the mask for baud rate counters. The controller * has two baud rate counters. One is used for High speed * operation, and the other is for std, fast mode, fast mode * plus operation. Currently we do not supprt high speed mode * so set brcr1 to 0. */ brcr1 = 0 << 16; brcr2 = (i2c_clk/(dev->cfg.clk_freq * div)) & 0xffff; /* set the baud rate counter register */ writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR); /* * set the speed mode. Currently we support * only standard and fast mode of operation * TODO - support for fast mode plus (upto 1Mb/s) * and high speed (up to 3.4 Mb/s) */ if (dev->cfg.sm > I2C_FREQ_MODE_FAST) { dev_err(&dev->pdev->dev, "do not support this mode " "defaulting to std. mode\n"); brcr2 = i2c_clk/(100000 * 2) & 0xffff; writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR); writel(I2C_FREQ_MODE_STANDARD << 4, dev->virtbase + I2C_CR); } writel(dev->cfg.sm << 4, dev->virtbase + I2C_CR); /* set the Tx and Rx FIFO threshold */ writel(dev->cfg.tft, dev->virtbase + I2C_TFTR); writel(dev->cfg.rft, dev->virtbase + I2C_RFTR); } /** * read_i2c() - Read from I2C client device * @dev: private data of I2C Driver * * This function reads from i2c client device when controller is in * master mode. There is a completion timeout. If there is no transfer * before timeout error is returned. */ static int read_i2c(struct nmk_i2c_dev *dev) { u32 status = 0; u32 mcr; u32 irq_mask = 0; int timeout; mcr = load_i2c_mcr_reg(dev); writel(mcr, dev->virtbase + I2C_MCR); /* load the current CR value */ writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR, dev->virtbase + I2C_CR); /* enable the controller */ i2c_set_bit(dev->virtbase + I2C_CR, I2C_CR_PE); init_completion(&dev->xfer_complete); /* enable interrupts by setting the mask */ irq_mask = (I2C_IT_RXFNF | I2C_IT_RXFF | I2C_IT_MAL | I2C_IT_BERR); if (dev->stop) irq_mask |= I2C_IT_MTD; else irq_mask |= I2C_IT_MTDWS; irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask); writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask, dev->virtbase + I2C_IMSCR); timeout = wait_for_completion_interruptible_timeout( &dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS)); if (timeout < 0) { dev_err(&dev->pdev->dev, "wait_for_completion_interruptible_timeout" "returned %d waiting for event\n", timeout); status = timeout; } if (timeout == 0) { /* controler has timedout, re-init the h/w */ dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n"); (void) init_hw(dev); status = -ETIMEDOUT; } return status; } /** * write_i2c() - Write data to I2C client. * @dev: private data of I2C Driver * * This function writes data to I2C client */ static int write_i2c(struct nmk_i2c_dev *dev) { u32 status = 0; u32 mcr; u32 irq_mask = 0; int timeout; mcr = load_i2c_mcr_reg(dev); writel(mcr, dev->virtbase + I2C_MCR); /* load the current CR value */ writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR, dev->virtbase + I2C_CR); /* enable the controller */ i2c_set_bit(dev->virtbase + I2C_CR , I2C_CR_PE); init_completion(&dev->xfer_complete); /* enable interrupts by settings the masks */ irq_mask = (I2C_IT_TXFNE | I2C_IT_TXFOVR | I2C_IT_MAL | I2C_IT_BERR); /* * check if we want to transfer a single or multiple bytes, if so * set the MTDWS bit (Master Transaction Done Without Stop) * to start repeated start operation */ if (dev->stop) irq_mask |= I2C_IT_MTD; else irq_mask |= I2C_IT_MTDWS; irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask); writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask, dev->virtbase + I2C_IMSCR); timeout = wait_for_completion_interruptible_timeout( &dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS)); if (timeout < 0) { dev_err(&dev->pdev->dev, "wait_for_completion_interruptible_timeout" "returned %d waiting for event\n", timeout); status = timeout; } if (timeout == 0) { /* controler has timedout, re-init the h/w */ dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n"); (void) init_hw(dev); status = -ETIMEDOUT; } return status; } /** * nmk_i2c_xfer() - I2C transfer function used by kernel framework * @i2c_adap: Adapter pointer to the controller * @msgs: Pointer to data to be written. * @num_msgs: Number of messages to be executed * * This is the function called by the generic kernel i2c_transfer() * or i2c_smbus...() API calls. Note that this code is protected by the * semaphore set in the kernel i2c_transfer() function. * * NOTE: * READ TRANSFER : We impose a restriction of the first message to be the * index message for any read transaction. * - a no index is coded as '0', * - 2byte big endian index is coded as '3' * !!! msg[0].buf holds the actual index. * This is compatible with generic messages of smbus emulator * that send a one byte index. * eg. a I2C transation to read 2 bytes from index 0 * idx = 0; * msg[0].addr = client->addr; * msg[0].flags = 0x0; * msg[0].len = 1; * msg[0].buf = &idx; * * msg[1].addr = client->addr; * msg[1].flags = I2C_M_RD; * msg[1].len = 2; * msg[1].buf = rd_buff * i2c_transfer(adap, msg, 2); * * WRITE TRANSFER : The I2C standard interface interprets all data as payload. * If you want to emulate an SMBUS write transaction put the * index as first byte(or first and second) in the payload. * eg. a I2C transation to write 2 bytes from index 1 * wr_buff[0] = 0x1; * wr_buff[1] = 0x23; * wr_buff[2] = 0x46; * msg[0].flags = 0x0; * msg[0].len = 3; * msg[0].buf = wr_buff; * i2c_transfer(adap, msg, 1); * * To read or write a block of data (multiple bytes) using SMBUS emulation * please use the i2c_smbus_read_i2c_block_data() * or i2c_smbus_write_i2c_block_data() API */ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num_msgs) { int status; int i; u32 cause; struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap); status = init_hw(dev); if (status) return status; /* setup the i2c controller */ setup_i2c_controller(dev); for (i = 0; i < num_msgs; i++) { if (unlikely(msgs[i].flags & I2C_M_TEN)) { dev_err(&dev->pdev->dev, "10 bit addressing" "not supported\n"); return -EINVAL; } dev->cli.slave_adr = msgs[i].addr; dev->cli.buffer = msgs[i].buf; dev->cli.count = msgs[i].len; dev->stop = (i < (num_msgs - 1)) ? 0 : 1; dev->result = 0; if (msgs[i].flags & I2C_M_RD) { /* it is a read operation */ dev->cli.operation = I2C_READ; status = read_i2c(dev); } else { /* write operation */ dev->cli.operation = I2C_WRITE; status = write_i2c(dev); } if (status || (dev->result)) { /* get the abort cause */ cause = (readl(dev->virtbase + I2C_SR) >> 4) & 0x7; dev_err(&dev->pdev->dev, "error during I2C" "message xfer: %d\n", cause); dev_err(&dev->pdev->dev, "%s\n", cause >= ARRAY_SIZE(abort_causes) ? "unknown reason" : abort_causes[cause]); return status; } mdelay(1); } /* return the no. messages processed */ if (status) return status; else return num_msgs; } /** * disable_interrupts() - disable the interrupts * @dev: private data of controller * @irq: interrupt number */ static int disable_interrupts(struct nmk_i2c_dev *dev, u32 irq) { irq = IRQ_MASK(irq); writel(readl(dev->virtbase + I2C_IMSCR) & ~(I2C_CLEAR_ALL_INTS & irq), dev->virtbase + I2C_IMSCR); return 0; } /** * i2c_irq_handler() - interrupt routine * @irq: interrupt number * @arg: data passed to the handler * * This is the interrupt handler for the i2c driver. Currently * it handles the major interrupts like Rx & Tx FIFO management * interrupts, master transaction interrupts, arbitration and * bus error interrupts. The rest of the interrupts are treated as * unhandled. */ static irqreturn_t i2c_irq_handler(int irq, void *arg) { struct nmk_i2c_dev *dev = arg; u32 tft, rft; u32 count; u32 misr; u32 src = 0; /* load Tx FIFO and Rx FIFO threshold values */ tft = readl(dev->virtbase + I2C_TFTR); rft = readl(dev->virtbase + I2C_RFTR); /* read interrupt status register */ misr = readl(dev->virtbase + I2C_MISR); src = __ffs(misr); switch ((1 << src)) { /* Transmit FIFO nearly empty interrupt */ case I2C_IT_TXFNE: { if (dev->cli.operation == I2C_READ) { /* * in read operation why do we care for writing? * so disable the Transmit FIFO interrupt */ disable_interrupts(dev, I2C_IT_TXFNE); } else { for (count = (MAX_I2C_FIFO_THRESHOLD - tft - 2); (count > 0) && (dev->cli.count != 0); count--) { /* write to the Tx FIFO */ writeb(*dev->cli.buffer, dev->virtbase + I2C_TFR); dev->cli.buffer++; dev->cli.count--; dev->cli.xfer_bytes++; } /* * if done, close the transfer by disabling the * corresponding TXFNE interrupt */ if (dev->cli.count == 0) disable_interrupts(dev, I2C_IT_TXFNE); } } break; /* * Rx FIFO nearly full interrupt. * This is set when the numer of entries in Rx FIFO is * greater or equal than the threshold value programmed * in RFT */ case I2C_IT_RXFNF: for (count = rft; count > 0; count--) { /* Read the Rx FIFO */ *dev->cli.buffer = readb(dev->virtbase + I2C_RFR); dev->cli.buffer++; } dev->cli.count -= rft; dev->cli.xfer_bytes += rft; break; /* Rx FIFO full */ case I2C_IT_RXFF: for (count = MAX_I2C_FIFO_THRESHOLD; count > 0; count--) { *dev->cli.buffer = readb(dev->virtbase + I2C_RFR); dev->cli.buffer++; } dev->cli.count -= MAX_I2C_FIFO_THRESHOLD; dev->cli.xfer_bytes += MAX_I2C_FIFO_THRESHOLD; break; /* Master Transaction Done with/without stop */ case I2C_IT_MTD: case I2C_IT_MTDWS: if (dev->cli.operation == I2C_READ) { while (!(readl(dev->virtbase + I2C_RISR) & I2C_IT_RXFE)) { if (dev->cli.count == 0) break; *dev->cli.buffer = readb(dev->virtbase + I2C_RFR); dev->cli.buffer++; dev->cli.count--; dev->cli.xfer_bytes++; } } i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTD); i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTDWS); disable_interrupts(dev, (I2C_IT_TXFNE | I2C_IT_TXFE | I2C_IT_TXFF | I2C_IT_TXFOVR | I2C_IT_RXFNF | I2C_IT_RXFF | I2C_IT_RXFE)); if (dev->cli.count) { dev->result = -1; dev_err(&dev->pdev->dev, "%lu bytes still remain to be" "xfered\n", dev->cli.count); (void) init_hw(dev); } complete(&dev->xfer_complete); break; /* Master Arbitration lost interrupt */ case I2C_IT_MAL: dev->result = -1; (void) init_hw(dev); i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MAL); complete(&dev->xfer_complete); break; /* * Bus Error interrupt. * This happens when an unexpected start/stop condition occurs * during the transaction. */ case I2C_IT_BERR: dev->result = -1; /* get the status */ if (((readl(dev->virtbase + I2C_SR) >> 2) & 0x3) == I2C_ABORT) (void) init_hw(dev); i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_BERR); complete(&dev->xfer_complete); break; /* * Tx FIFO overrun interrupt. * This is set when a write operation in Tx FIFO is performed and * the Tx FIFO is full. */ case I2C_IT_TXFOVR: dev->result = -1; (void) init_hw(dev); dev_err(&dev->pdev->dev, "Tx Fifo Over run\n"); complete(&dev->xfer_complete); break; /* unhandled interrupts by this driver - TODO*/ case I2C_IT_TXFE: case I2C_IT_TXFF: case I2C_IT_RXFE: case I2C_IT_RFSR: case I2C_IT_RFSE: case I2C_IT_WTSR: case I2C_IT_STD: dev_err(&dev->pdev->dev, "unhandled Interrupt\n"); break; default: dev_err(&dev->pdev->dev, "spurious Interrupt..\n"); break; } return IRQ_HANDLED; } static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK; } static const struct i2c_algorithm nmk_i2c_algo = { .master_xfer = nmk_i2c_xfer, .functionality = nmk_i2c_functionality }; static int __devinit nmk_i2c_probe(struct platform_device *pdev) { int ret = 0; struct resource *res; struct nmk_i2c_controller *pdata = pdev->dev.platform_data; struct nmk_i2c_dev *dev; struct i2c_adapter *adap; dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL); if (!dev) { dev_err(&pdev->dev, "cannot allocate memory\n"); ret = -ENOMEM; goto err_no_mem; } dev->pdev = pdev; platform_set_drvdata(pdev, dev); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { ret = -ENOENT; goto err_no_resource; } if (request_mem_region(res->start, resource_size(res), DRIVER_NAME "I/O region") == NULL) { ret = -EBUSY; goto err_no_region; } dev->virtbase = ioremap(res->start, resource_size(res)); if (!dev->virtbase) { ret = -ENOMEM; goto err_no_ioremap; } dev->irq = platform_get_irq(pdev, 0); ret = request_irq(dev->irq, i2c_irq_handler, IRQF_DISABLED, DRIVER_NAME, dev); if (ret) { dev_err(&pdev->dev, "cannot claim the irq %d\n", dev->irq); goto err_irq; } dev->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(dev->clk)) { dev_err(&pdev->dev, "could not get i2c clock\n"); ret = PTR_ERR(dev->clk); goto err_no_clk; } clk_enable(dev->clk); adap = &dev->adap; adap->dev.parent = &pdev->dev; adap->owner = THIS_MODULE; adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; adap->algo = &nmk_i2c_algo; /* fetch the controller id */ adap->nr = pdev->id; /* fetch the controller configuration from machine */ dev->cfg.clk_freq = pdata->clk_freq; dev->cfg.slsu = pdata->slsu; dev->cfg.tft = pdata->tft; dev->cfg.rft = pdata->rft; dev->cfg.sm = pdata->sm; i2c_set_adapdata(adap, dev); ret = init_hw(dev); if (ret != 0) { dev_err(&pdev->dev, "error in initializing i2c hardware\n"); goto err_init_hw; } dev_dbg(&pdev->dev, "initialize I2C%d bus on virtual " "base %p\n", pdev->id, dev->virtbase); ret = i2c_add_numbered_adapter(adap); if (ret) { dev_err(&pdev->dev, "failed to add adapter\n"); goto err_add_adap; } return 0; err_init_hw: clk_disable(dev->clk); err_add_adap: clk_put(dev->clk); err_no_clk: free_irq(dev->irq, dev); err_irq: iounmap(dev->virtbase); err_no_ioremap: release_mem_region(res->start, resource_size(res)); err_no_region: platform_set_drvdata(pdev, NULL); err_no_resource: kfree(dev); err_no_mem: return ret; } static int __devexit nmk_i2c_remove(struct platform_device *pdev) { struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); struct nmk_i2c_dev *dev = platform_get_drvdata(pdev); i2c_del_adapter(&dev->adap); flush_i2c_fifo(dev); disable_all_interrupts(dev); clear_all_interrupts(dev); /* disable the controller */ i2c_clr_bit(dev->virtbase + I2C_CR, I2C_CR_PE); free_irq(dev->irq, dev); iounmap(dev->virtbase); if (res) release_mem_region(res->start, resource_size(res)); clk_disable(dev->clk); clk_put(dev->clk); platform_set_drvdata(pdev, NULL); kfree(dev); return 0; } static struct platform_driver nmk_i2c_driver = { .driver = { .owner = THIS_MODULE, .name = DRIVER_NAME, }, .probe = nmk_i2c_probe, .remove = __devexit_p(nmk_i2c_remove), }; static int __init nmk_i2c_init(void) { return platform_driver_register(&nmk_i2c_driver); } static void __exit nmk_i2c_exit(void) { platform_driver_unregister(&nmk_i2c_driver); } subsys_initcall(nmk_i2c_init); module_exit(nmk_i2c_exit); MODULE_AUTHOR("Sachin Verma, Srinidhi KASAGAR"); MODULE_DESCRIPTION("Nomadik/Ux500 I2C driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:" DRIVER_NAME);