diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-nomadik.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-nomadik.c | 959 |
1 files changed, 959 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c new file mode 100644 index 000000000000..a15f731fa451 --- /dev/null +++ b/drivers/i2c/busses/i2c-nomadik.c @@ -0,0 +1,959 @@ +/* + * Copyright (C) 2009 ST-Ericsson + * Copyright (C) 2009 STMicroelectronics + * + * I2C master mode controller driver, used in Nomadik 8815 + * and Ux500 platforms. + * + * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> + * Author: Sachin Verma <sachin.verma@st.com> + * + * 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 <linux/init.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/i2c.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> + +#include <plat/i2c.h> + +#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 + */ +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 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); + 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); |