--- /dev/null
+/*
+ * 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 <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/amba/bus.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.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_freq_mode {
+ I2C_FREQ_MODE_STANDARD, /* up to 100 Kb/s */
+ I2C_FREQ_MODE_FAST, /* up to 400 Kb/s */
+ I2C_FREQ_MODE_HIGH_SPEED, /* up to 3.4 Mb/s */
+ I2C_FREQ_MODE_FAST_PLUS, /* up to 1 Mb/s */
+};
+
+/**
+ * struct i2c_vendor_data - per-vendor variations
+ * @has_mtdws: variant has the MTDWS bit
+ * @fifodepth: variant FIFO depth
+ */
+struct i2c_vendor_data {
+ bool has_mtdws;
+ u32 fifodepth;
+};
+
+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
+};
+
+/**
+ * struct i2c_nmk_client - client specific data
+ * @slave_adr: 7-bit slave address
+ * @count: no. bytes to be transferred
+ * @buffer: client data buffer
+ * @xfer_bytes: bytes transferred 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.
+ * @vendor: vendor data for this variant.
+ * @adev: parent amba device.
+ * @adap: corresponding I2C adapter.
+ * @irq: interrupt line for the controller.
+ * @virtbase: virtual io memory area.
+ * @clk: hardware i2c block clock.
+ * @cli: holder of client specific data.
+ * @clk_freq: clock frequency for the operation mode
+ * @tft: Tx FIFO Threshold in bytes
+ * @rft: Rx FIFO Threshold in bytes
+ * @timeout Slave response timeout (ms)
+ * @sm: speed mode
+ * @stop: stop condition.
+ * @xfer_complete: acknowledge completion for a I2C message.
+ * @result: controller propogated result.
+ */
+struct nmk_i2c_dev {
+ struct i2c_vendor_data *vendor;
+ struct amba_device *adev;
+ struct i2c_adapter adap;
+ int irq;
+ void __iomem *virtbase;
+ struct clk *clk;
+ struct i2c_nmk_client cli;
+ u32 clk_freq;
+ unsigned char tft;
+ unsigned char rft;
+ int timeout;
+ enum i2c_freq_mode sm;
+ 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 + dev->adap.timeout;
+
+ while (!time_after(jiffies, timeout)) {
+ if ((readl(dev->virtbase + I2C_CR) &
+ (I2C_CR_FTX | I2C_CR_FRX)) == 0)
+ return 0;
+ }
+ }
+
+ dev_err(&dev->adev->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)
+ goto exit;
+
+ /* 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;
+
+exit:
+ return stat;
+}
+
+/* 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
+ * @flags: message flags
+ */
+static u32 load_i2c_mcr_reg(struct nmk_i2c_dev *dev, u16 flags)
+{
+ u32 mcr = 0;
+ unsigned short slave_adr_3msb_bits;
+
+ mcr |= GEN_MASK(dev->cli.slave_adr, I2C_MCR_A7, 1);
+
+ if (unlikely(flags & I2C_M_TEN)) {
+ /* 10-bit address transaction */
+ mcr |= GEN_MASK(2, I2C_MCR_AM, 12);
+ /*
+ * Get the top 3 bits.
+ * EA10 represents extended address in MCR. This includes
+ * the extension (MSB bits) of the 7 bit address loaded
+ * in A7
+ */
+ slave_adr_3msb_bits = (dev->cli.slave_adr >> 7) & 0x7;
+
+ mcr |= GEN_MASK(slave_adr_3msb_bits, I2C_MCR_EA10, 8);
+ } else {
+ /* 7-bit address transaction */
+ mcr |= GEN_MASK(1, I2C_MCR_AM, 12);
+ }
+
+ /* 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;
+ u32 ns;
+ u16 slsu;
+
+ 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);
+
+ i2c_clk = clk_get_rate(dev->clk);
+
+ /*
+ * set the slsu:
+ *
+ * slsu defines the data setup time after SCL clock
+ * stretching in terms of i2c clk cycles + 1 (zero means
+ * "wait one cycle"), the needed setup time for the three
+ * modes are 250ns, 100ns, 10ns respectively.
+ *
+ * As the time for one cycle T in nanoseconds is
+ * T = (1/f) * 1000000000 =>
+ * slsu = cycles / (1000000000 / f) + 1
+ */
+ ns = DIV_ROUND_UP_ULL(1000000000ULL, i2c_clk);
+ switch (dev->sm) {
+ case I2C_FREQ_MODE_FAST:
+ case I2C_FREQ_MODE_FAST_PLUS:
+ slsu = DIV_ROUND_UP(100, ns); /* Fast */
+ break;
+ case I2C_FREQ_MODE_HIGH_SPEED:
+ slsu = DIV_ROUND_UP(10, ns); /* High */
+ break;
+ case I2C_FREQ_MODE_STANDARD:
+ default:
+ slsu = DIV_ROUND_UP(250, ns); /* Standard */
+ break;
+ }
+ slsu += 1;
+
+ dev_dbg(&dev->adev->dev, "calculated SLSU = %04x\n", slsu);
+ writel(slsu << 16, dev->virtbase + I2C_SCR);
+
+ /*
+ * 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->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->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 (up to 1Mb/s)
+ * and high speed (up to 3.4 Mb/s)
+ */
+ if (dev->sm > I2C_FREQ_MODE_FAST) {
+ dev_err(&dev->adev->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->sm << 4, dev->virtbase + I2C_CR);
+
+ /* set the Tx and Rx FIFO threshold */
+ writel(dev->tft, dev->virtbase + I2C_TFTR);
+ writel(dev->rft, dev->virtbase + I2C_RFTR);
+}
+
+/**
+ * read_i2c() - Read from I2C client device
+ * @dev: private data of I2C Driver
+ * @flags: message flags
+ *
+ * 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, u16 flags)
+{
+ int status = 0;
+ u32 mcr, irq_mask;
+ unsigned long timeout;
+
+ mcr = load_i2c_mcr_reg(dev, flags);
+ 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 || !dev->vendor->has_mtdws)
+ 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_timeout(
+ &dev->xfer_complete, dev->adap.timeout);
+
+ if (timeout == 0) {
+ /* Controller timed out */
+ dev_err(&dev->adev->dev, "read from slave 0x%x timed out\n",
+ dev->cli.slave_adr);
+ status = -ETIMEDOUT;
+ }
+ return status;
+}
+
+static void fill_tx_fifo(struct nmk_i2c_dev *dev, int no_bytes)
+{
+ int count;
+
+ for (count = (no_bytes - 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++;
+ }
+
+}
+
+/**
+ * write_i2c() - Write data to I2C client.
+ * @dev: private data of I2C Driver
+ * @flags: message flags
+ *
+ * This function writes data to I2C client
+ */
+static int write_i2c(struct nmk_i2c_dev *dev, u16 flags)
+{
+ u32 status = 0;
+ u32 mcr, irq_mask;
+ unsigned long timeout;
+
+ mcr = load_i2c_mcr_reg(dev, flags);
+
+ 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_TXFOVR | I2C_IT_MAL | I2C_IT_BERR);
+
+ /* Fill the TX FIFO with transmit data */
+ fill_tx_fifo(dev, MAX_I2C_FIFO_THRESHOLD);
+
+ if (dev->cli.count != 0)
+ irq_mask |= I2C_IT_TXFNE;
+
+ /*
+ * 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 || !dev->vendor->has_mtdws)
+ 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_timeout(
+ &dev->xfer_complete, dev->adap.timeout);
+
+ if (timeout == 0) {
+ /* Controller timed out */
+ dev_err(&dev->adev->dev, "write to slave 0x%x timed out\n",
+ dev->cli.slave_adr);
+ status = -ETIMEDOUT;
+ }
+
+ return status;
+}
+
+/**
+ * nmk_i2c_xfer_one() - transmit a single I2C message
+ * @dev: device with a message encoded into it
+ * @flags: message flags
+ */
+static int nmk_i2c_xfer_one(struct nmk_i2c_dev *dev, u16 flags)
+{
+ int status;
+
+ if (flags & I2C_M_RD) {
+ /* read operation */
+ dev->cli.operation = I2C_READ;
+ status = read_i2c(dev, flags);
+ } else {
+ /* write operation */
+ dev->cli.operation = I2C_WRITE;
+ status = write_i2c(dev, flags);
+ }
+
+ if (status || (dev->result)) {
+ u32 i2c_sr;
+ u32 cause;
+
+ i2c_sr = readl(dev->virtbase + I2C_SR);
+ /*
+ * Check if the controller I2C operation status
+ * is set to ABORT(11b).
+ */
+ if (((i2c_sr >> 2) & 0x3) == 0x3) {
+ /* get the abort cause */
+ cause = (i2c_sr >> 4) & 0x7;
+ dev_err(&dev->adev->dev, "%s\n",
+ cause >= ARRAY_SIZE(abort_causes) ?
+ "unknown reason" :
+ abort_causes[cause]);
+ }
+
+ (void) init_hw(dev);
+
+ status = status ? status : dev->result;
+ }
+
+ 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 = 0;
+ int i;
+ struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
+ int j;
+
+ pm_runtime_get_sync(&dev->adev->dev);
+
+ /* Attempt three times to send the message queue */
+ for (j = 0; j < 3; j++) {
+ /* setup the i2c controller */
+ setup_i2c_controller(dev);
+
+ for (i = 0; i < num_msgs; i++) {
+ 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;
+
+ status = nmk_i2c_xfer_one(dev, msgs[i].flags);
+ if (status != 0)
+ break;
+ }
+ if (status == 0)
+ break;
+ }
+
+ pm_runtime_put_sync(&dev->adev->dev);
+
+ /* 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, src;
+
+ /* 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 {
+ fill_tx_fifo(dev, (MAX_I2C_FIFO_THRESHOLD - tft));
+ /*
+ * 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++;
+ }
+ }
+
+ disable_all_interrupts(dev);
+ clear_all_interrupts(dev);
+
+ if (dev->cli.count) {
+ dev->result = -EIO;
+ dev_err(&dev->adev->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 = -EIO;
+ (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 = -EIO;
+ /* 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 = -EIO;
+ (void) init_hw(dev);
+
+ dev_err(&dev->adev->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->adev->dev, "unhandled Interrupt\n");
+ break;
+ default:
+ dev_err(&dev->adev->dev, "spurious Interrupt..\n");
+ break;
+ }
+
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int nmk_i2c_suspend_late(struct device *dev)
+{
+ int ret;
+
+ ret = pm_runtime_force_suspend(dev);
+ if (ret)
+ return ret;
+
+ pinctrl_pm_select_sleep_state(dev);
+ return 0;
+}
+
+static int nmk_i2c_resume_early(struct device *dev)
+{
+ return pm_runtime_force_resume(dev);
+}
+#endif
+
+#ifdef CONFIG_PM
+static int nmk_i2c_runtime_suspend(struct device *dev)
+{
+ struct amba_device *adev = to_amba_device(dev);
+ struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);
+
+ clk_disable_unprepare(nmk_i2c->clk);
+ pinctrl_pm_select_idle_state(dev);
+ return 0;
+}
+
+static int nmk_i2c_runtime_resume(struct device *dev)
+{
+ struct amba_device *adev = to_amba_device(dev);
+ struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);
+ int ret;
+
+ ret = clk_prepare_enable(nmk_i2c->clk);
+ if (ret) {
+ dev_err(dev, "can't prepare_enable clock\n");
+ return ret;
+ }
+
+ pinctrl_pm_select_default_state(dev);
+
+ ret = init_hw(nmk_i2c);
+ if (ret) {
+ clk_disable_unprepare(nmk_i2c->clk);
+ pinctrl_pm_select_idle_state(dev);
+ }
+
+ return ret;
+}
+#endif
+
+static const struct dev_pm_ops nmk_i2c_pm = {
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(nmk_i2c_suspend_late, nmk_i2c_resume_early)
+ SET_RUNTIME_PM_OPS(nmk_i2c_runtime_suspend,
+ nmk_i2c_runtime_resume,
+ NULL)
+};
+
+static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
+}
+
+static const struct i2c_algorithm nmk_i2c_algo = {
+ .master_xfer = nmk_i2c_xfer,
+ .functionality = nmk_i2c_functionality
+};
+
+static void nmk_i2c_of_probe(struct device_node *np,
+ struct nmk_i2c_dev *nmk)
+{
+ /* Default to 100 kHz if no frequency is given in the node */
+ if (of_property_read_u32(np, "clock-frequency", &nmk->clk_freq))
+ nmk->clk_freq = 100000;
+
+ /* This driver only supports 'standard' and 'fast' modes of operation. */
+ if (nmk->clk_freq <= 100000)
+ nmk->sm = I2C_FREQ_MODE_STANDARD;
+ else
+ nmk->sm = I2C_FREQ_MODE_FAST;
+ nmk->tft = 1; /* Tx FIFO threshold */
+ nmk->rft = 8; /* Rx FIFO threshold */
+ nmk->timeout = 200; /* Slave response timeout(ms) */
+}
+
+static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ int ret = 0;
+ struct device_node *np = adev->dev.of_node;
+ struct nmk_i2c_dev *dev;
+ struct i2c_adapter *adap;
+ struct i2c_vendor_data *vendor = id->data;
+ u32 max_fifo_threshold = (vendor->fifodepth / 2) - 1;
+
+ dev = devm_kzalloc(&adev->dev, sizeof(struct nmk_i2c_dev), GFP_KERNEL);
+ if (!dev) {
+ dev_err(&adev->dev, "cannot allocate memory\n");
+ ret = -ENOMEM;
+ goto err_no_mem;
+ }
+ dev->vendor = vendor;
+ dev->adev = adev;
+ nmk_i2c_of_probe(np, dev);
+
+ if (dev->tft > max_fifo_threshold) {
+ dev_warn(&adev->dev, "requested TX FIFO threshold %u, adjusted down to %u\n",
+ dev->tft, max_fifo_threshold);
+ dev->tft = max_fifo_threshold;
+ }
+
+ if (dev->rft > max_fifo_threshold) {
+ dev_warn(&adev->dev, "requested RX FIFO threshold %u, adjusted down to %u\n",
+ dev->rft, max_fifo_threshold);
+ dev->rft = max_fifo_threshold;
+ }
+
+ amba_set_drvdata(adev, dev);
+
+ dev->virtbase = devm_ioremap(&adev->dev, adev->res.start,
+ resource_size(&adev->res));
+ if (!dev->virtbase) {
+ ret = -ENOMEM;
+ goto err_no_mem;
+ }
+
+ dev->irq = adev->irq[0];
+ ret = devm_request_irq(&adev->dev, dev->irq, i2c_irq_handler, 0,
+ DRIVER_NAME, dev);
+ if (ret) {
+ dev_err(&adev->dev, "cannot claim the irq %d\n", dev->irq);
+ goto err_no_mem;
+ }
+
+ pm_suspend_ignore_children(&adev->dev, true);
+
+ dev->clk = devm_clk_get(&adev->dev, NULL);
+ if (IS_ERR(dev->clk)) {
+ dev_err(&adev->dev, "could not get i2c clock\n");
+ ret = PTR_ERR(dev->clk);
+ goto err_no_mem;
+ }
+
+ ret = clk_prepare_enable(dev->clk);
+ if (ret) {
+ dev_err(&adev->dev, "can't prepare_enable clock\n");
+ goto err_no_mem;
+ }
+
+ init_hw(dev);
+
+ adap = &dev->adap;
+ adap->dev.of_node = np;
+ adap->dev.parent = &adev->dev;
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_DEPRECATED;
+ adap->algo = &nmk_i2c_algo;
+ adap->timeout = msecs_to_jiffies(dev->timeout);
+ snprintf(adap->name, sizeof(adap->name),
+ "Nomadik I2C at %pR", &adev->res);
+
+ i2c_set_adapdata(adap, dev);
+
+ dev_info(&adev->dev,
+ "initialize %s on virtual base %p\n",
+ adap->name, dev->virtbase);
+
+ ret = i2c_add_adapter(adap);
+ if (ret) {
+ dev_err(&adev->dev, "failed to add adapter\n");
+ goto err_no_adap;
+ }
+
+ pm_runtime_put(&adev->dev);
+
+ return 0;
+
+ err_no_adap:
+ clk_disable_unprepare(dev->clk);
+ err_no_mem:
+
+ return ret;
+}
+
+static int nmk_i2c_remove(struct amba_device *adev)
+{
+ struct resource *res = &adev->res;
+ struct nmk_i2c_dev *dev = amba_get_drvdata(adev);
+
+ 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);
+ clk_disable_unprepare(dev->clk);
+ if (res)
+ release_mem_region(res->start, resource_size(res));
+
+ return 0;
+}
+
+static struct i2c_vendor_data vendor_stn8815 = {
+ .has_mtdws = false,
+ .fifodepth = 16, /* Guessed from TFTR/RFTR = 7 */
+};
+
+static struct i2c_vendor_data vendor_db8500 = {
+ .has_mtdws = true,
+ .fifodepth = 32, /* Guessed from TFTR/RFTR = 15 */
+};
+
+static struct amba_id nmk_i2c_ids[] = {
+ {
+ .id = 0x00180024,
+ .mask = 0x00ffffff,
+ .data = &vendor_stn8815,
+ },
+ {
+ .id = 0x00380024,
+ .mask = 0x00ffffff,
+ .data = &vendor_db8500,
+ },
+ {},
+};
+
+MODULE_DEVICE_TABLE(amba, nmk_i2c_ids);
+
+static struct amba_driver nmk_i2c_driver = {
+ .drv = {
+ .owner = THIS_MODULE,
+ .name = DRIVER_NAME,
+ .pm = &nmk_i2c_pm,
+ },
+ .id_table = nmk_i2c_ids,
+ .probe = nmk_i2c_probe,
+ .remove = nmk_i2c_remove,
+};
+
+static int __init nmk_i2c_init(void)
+{
+ return amba_driver_register(&nmk_i2c_driver);
+}
+
+static void __exit nmk_i2c_exit(void)
+{
+ amba_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");
Code Review / kvmfornfv.git / blobdiff