--- /dev/null
+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+/* Hardware register offsets and field defintions */
+#define CS_OFFSET 0x00000020
+#define CS_ACK_SHIFT 3
+#define CS_ACK_MASK 0x00000008
+#define CS_ACK_CMD_GEN_START 0x00000000
+#define CS_ACK_CMD_GEN_RESTART 0x00000001
+#define CS_CMD_SHIFT 1
+#define CS_CMD_CMD_NO_ACTION 0x00000000
+#define CS_CMD_CMD_START_RESTART 0x00000001
+#define CS_CMD_CMD_STOP 0x00000002
+#define CS_EN_SHIFT 0
+#define CS_EN_CMD_ENABLE_BSC 0x00000001
+
+#define TIM_OFFSET 0x00000024
+#define TIM_PRESCALE_SHIFT 6
+#define TIM_P_SHIFT 3
+#define TIM_NO_DIV_SHIFT 2
+#define TIM_DIV_SHIFT 0
+
+#define DAT_OFFSET 0x00000028
+
+#define TOUT_OFFSET 0x0000002c
+
+#define TXFCR_OFFSET 0x0000003c
+#define TXFCR_FIFO_FLUSH_MASK 0x00000080
+#define TXFCR_FIFO_EN_MASK 0x00000040
+
+#define IER_OFFSET 0x00000044
+#define IER_READ_COMPLETE_INT_MASK 0x00000010
+#define IER_I2C_INT_EN_MASK 0x00000008
+#define IER_FIFO_INT_EN_MASK 0x00000002
+#define IER_NOACK_EN_MASK 0x00000001
+
+#define ISR_OFFSET 0x00000048
+#define ISR_RESERVED_MASK 0xffffff60
+#define ISR_CMDBUSY_MASK 0x00000080
+#define ISR_READ_COMPLETE_MASK 0x00000010
+#define ISR_SES_DONE_MASK 0x00000008
+#define ISR_ERR_MASK 0x00000004
+#define ISR_TXFIFOEMPTY_MASK 0x00000002
+#define ISR_NOACK_MASK 0x00000001
+
+#define CLKEN_OFFSET 0x0000004C
+#define CLKEN_AUTOSENSE_OFF_MASK 0x00000080
+#define CLKEN_M_SHIFT 4
+#define CLKEN_N_SHIFT 1
+#define CLKEN_CLKEN_MASK 0x00000001
+
+#define FIFO_STATUS_OFFSET 0x00000054
+#define FIFO_STATUS_RXFIFO_EMPTY_MASK 0x00000004
+#define FIFO_STATUS_TXFIFO_EMPTY_MASK 0x00000010
+
+#define HSTIM_OFFSET 0x00000058
+#define HSTIM_HS_MODE_MASK 0x00008000
+#define HSTIM_HS_HOLD_SHIFT 10
+#define HSTIM_HS_HIGH_PHASE_SHIFT 5
+#define HSTIM_HS_SETUP_SHIFT 0
+
+#define PADCTL_OFFSET 0x0000005c
+#define PADCTL_PAD_OUT_EN_MASK 0x00000004
+
+#define RXFCR_OFFSET 0x00000068
+#define RXFCR_NACK_EN_SHIFT 7
+#define RXFCR_READ_COUNT_SHIFT 0
+#define RXFIFORDOUT_OFFSET 0x0000006c
+
+/* Locally used constants */
+#define MAX_RX_FIFO_SIZE 64U /* bytes */
+#define MAX_TX_FIFO_SIZE 64U /* bytes */
+
+#define STD_EXT_CLK_FREQ 13000000UL
+#define HS_EXT_CLK_FREQ 104000000UL
+
+#define MASTERCODE 0x08 /* Mastercodes are 0000_1xxxb */
+
+#define I2C_TIMEOUT 100 /* msecs */
+
+/* Operations that can be commanded to the controller */
+enum bcm_kona_cmd_t {
+ BCM_CMD_NOACTION = 0,
+ BCM_CMD_START,
+ BCM_CMD_RESTART,
+ BCM_CMD_STOP,
+};
+
+enum bus_speed_index {
+ BCM_SPD_100K = 0,
+ BCM_SPD_400K,
+ BCM_SPD_1MHZ,
+};
+
+enum hs_bus_speed_index {
+ BCM_SPD_3P4MHZ = 0,
+};
+
+/* Internal divider settings for standard mode, fast mode and fast mode plus */
+struct bus_speed_cfg {
+ uint8_t time_m; /* Number of cycles for setup time */
+ uint8_t time_n; /* Number of cycles for hold time */
+ uint8_t prescale; /* Prescale divider */
+ uint8_t time_p; /* Timing coefficient */
+ uint8_t no_div; /* Disable clock divider */
+ uint8_t time_div; /* Post-prescale divider */
+};
+
+/* Internal divider settings for high-speed mode */
+struct hs_bus_speed_cfg {
+ uint8_t hs_hold; /* Number of clock cycles SCL stays low until
+ the end of bit period */
+ uint8_t hs_high_phase; /* Number of clock cycles SCL stays high
+ before it falls */
+ uint8_t hs_setup; /* Number of clock cycles SCL stays low
+ before it rises */
+ uint8_t prescale; /* Prescale divider */
+ uint8_t time_p; /* Timing coefficient */
+ uint8_t no_div; /* Disable clock divider */
+ uint8_t time_div; /* Post-prescale divider */
+};
+
+static const struct bus_speed_cfg std_cfg_table[] = {
+ [BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
+ [BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
+ [BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
+};
+
+static const struct hs_bus_speed_cfg hs_cfg_table[] = {
+ [BCM_SPD_3P4MHZ] = {0x01, 0x08, 0x14, 0x00, 0x06, 0x01, 0x00},
+};
+
+struct bcm_kona_i2c_dev {
+ struct device *device;
+
+ void __iomem *base;
+ int irq;
+ struct clk *external_clk;
+
+ struct i2c_adapter adapter;
+
+ struct completion done;
+
+ const struct bus_speed_cfg *std_cfg;
+ const struct hs_bus_speed_cfg *hs_cfg;
+};
+
+static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
+ enum bcm_kona_cmd_t cmd)
+{
+ dev_dbg(dev->device, "%s, %d\n", __func__, cmd);
+
+ switch (cmd) {
+ case BCM_CMD_NOACTION:
+ writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_START:
+ writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
+ (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_RESTART:
+ writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
+ (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_STOP:
+ writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ default:
+ dev_err(dev->device, "Unknown command %d\n", cmd);
+ }
+}
+
+static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static irqreturn_t bcm_kona_i2c_isr(int irq, void *devid)
+{
+ struct bcm_kona_i2c_dev *dev = devid;
+ uint32_t status = readl(dev->base + ISR_OFFSET);
+
+ if ((status & ~ISR_RESERVED_MASK) == 0)
+ return IRQ_NONE;
+
+ /* Must flush the TX FIFO when NAK detected */
+ if (status & ISR_NOACK_MASK)
+ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+ dev->base + TXFCR_OFFSET);
+
+ writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
+ complete_all(&dev->done);
+
+ return IRQ_HANDLED;
+}
+
+/* Wait for ISR_CMDBUSY_MASK to go low before writing to CS, DAT, or RCD */
+static int bcm_kona_i2c_wait_if_busy(struct bcm_kona_i2c_dev *dev)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
+
+ while (readl(dev->base + ISR_OFFSET) & ISR_CMDBUSY_MASK)
+ if (time_after(jiffies, timeout)) {
+ dev_err(dev->device, "CMDBUSY timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+/* Send command to I2C bus */
+static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
+ enum bcm_kona_cmd_t cmd)
+{
+ int rc;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+ /* Make sure the hardware is ready */
+ rc = bcm_kona_i2c_wait_if_busy(dev);
+ if (rc < 0)
+ return rc;
+
+ /* Unmask the session done interrupt */
+ writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+ /* Mark as incomplete before sending the command */
+ reinit_completion(&dev->done);
+
+ /* Send the command */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
+
+ /* Wait for transaction to finish or timeout */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_err(dev->device, "controller timed out\n");
+ rc = -ETIMEDOUT;
+ }
+
+ /* Clear command */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+ return rc;
+}
+
+/* Read a single RX FIFO worth of data from the i2c bus */
+static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
+ uint8_t *buf, unsigned int len,
+ unsigned int last_byte_nak)
+{
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+ /* Mark as incomplete before starting the RX FIFO */
+ reinit_completion(&dev->done);
+
+ /* Unmask the read complete interrupt */
+ writel(IER_READ_COMPLETE_INT_MASK, dev->base + IER_OFFSET);
+
+ /* Start the RX FIFO */
+ writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
+ (len << RXFCR_READ_COUNT_SHIFT),
+ dev->base + RXFCR_OFFSET);
+
+ /* Wait for FIFO read to complete */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_err(dev->device, "RX FIFO time out\n");
+ return -EREMOTEIO;
+ }
+
+ /* Read data from FIFO */
+ for (; len > 0; len--, buf++)
+ *buf = readl(dev->base + RXFIFORDOUT_OFFSET);
+
+ return 0;
+}
+
+/* Read any amount of data using the RX FIFO from the i2c bus */
+static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+{
+ unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
+ unsigned int last_byte_nak = 0;
+ unsigned int bytes_read = 0;
+ int rc;
+
+ uint8_t *tmp_buf = msg->buf;
+
+ while (bytes_read < msg->len) {
+ if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
+ last_byte_nak = 1; /* NAK last byte of transfer */
+ bytes_to_read = msg->len - bytes_read;
+ }
+
+ rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
+ last_byte_nak);
+ if (rc < 0)
+ return -EREMOTEIO;
+
+ bytes_read += bytes_to_read;
+ tmp_buf += bytes_to_read;
+ }
+
+ return 0;
+}
+
+/* Write a single byte of data to the i2c bus */
+static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
+ unsigned int nak_expected)
+{
+ int rc;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+ unsigned int nak_received;
+
+ /* Make sure the hardware is ready */
+ rc = bcm_kona_i2c_wait_if_busy(dev);
+ if (rc < 0)
+ return rc;
+
+ /* Clear pending session done interrupt */
+ writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
+
+ /* Unmask the session done interrupt */
+ writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+ /* Mark as incomplete before sending the data */
+ reinit_completion(&dev->done);
+
+ /* Send one byte of data */
+ writel(data, dev->base + DAT_OFFSET);
+
+ /* Wait for byte to be written */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_dbg(dev->device, "controller timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
+
+ if (nak_received ^ nak_expected) {
+ dev_dbg(dev->device, "unexpected NAK/ACK\n");
+ return -EREMOTEIO;
+ }
+
+ return 0;
+}
+
+/* Write a single TX FIFO worth of data to the i2c bus */
+static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
+ uint8_t *buf, unsigned int len)
+{
+ int k;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+ unsigned int fifo_status;
+
+ /* Mark as incomplete before sending data to the TX FIFO */
+ reinit_completion(&dev->done);
+
+ /* Unmask the fifo empty and nak interrupt */
+ writel(IER_FIFO_INT_EN_MASK | IER_NOACK_EN_MASK,
+ dev->base + IER_OFFSET);
+
+ /* Disable IRQ to load a FIFO worth of data without interruption */
+ disable_irq(dev->irq);
+
+ /* Write data into FIFO */
+ for (k = 0; k < len; k++)
+ writel(buf[k], (dev->base + DAT_OFFSET));
+
+ /* Enable IRQ now that data has been loaded */
+ enable_irq(dev->irq);
+
+ /* Wait for FIFO to empty */
+ do {
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+ fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
+ } while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ /* Check if there was a NAK */
+ if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
+ dev_err(dev->device, "unexpected NAK\n");
+ return -EREMOTEIO;
+ }
+
+ /* Check if a timeout occured */
+ if (!time_left) {
+ dev_err(dev->device, "completion timed out\n");
+ return -EREMOTEIO;
+ }
+
+ return 0;
+}
+
+
+/* Write any amount of data using TX FIFO to the i2c bus */
+static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+{
+ unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
+ unsigned int bytes_written = 0;
+ int rc;
+
+ uint8_t *tmp_buf = msg->buf;
+
+ while (bytes_written < msg->len) {
+ if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
+ bytes_to_write = msg->len - bytes_written;
+
+ rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
+ bytes_to_write);
+ if (rc < 0)
+ return -EREMOTEIO;
+
+ bytes_written += bytes_to_write;
+ tmp_buf += bytes_to_write;
+ }
+
+ return 0;
+}
+
+/* Send i2c address */
+static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+{
+ unsigned char addr;
+
+ if (msg->flags & I2C_M_TEN) {
+ /* First byte is 11110XX0 where XX is upper 2 bits */
+ addr = 0xF0 | ((msg->addr & 0x300) >> 7);
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+
+ /* Second byte is the remaining 8 bits */
+ addr = msg->addr & 0xFF;
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+
+ if (msg->flags & I2C_M_RD) {
+ /* For read, send restart command */
+ if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
+ return -EREMOTEIO;
+
+ /* Then re-send the first byte with the read bit set */
+ addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+ }
+ } else {
+ addr = msg->addr << 1;
+
+ if (msg->flags & I2C_M_RD)
+ addr |= 1;
+
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+ }
+
+ return 0;
+}
+
+static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
+{
+ writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
+ dev->base + HSTIM_OFFSET);
+
+ writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
+ (dev->std_cfg->time_p << TIM_P_SHIFT) |
+ (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
+ (dev->std_cfg->time_div << TIM_DIV_SHIFT),
+ dev->base + TIM_OFFSET);
+
+ writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
+ (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
+ CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_config_timing_hs(struct bcm_kona_i2c_dev *dev)
+{
+ writel((dev->hs_cfg->prescale << TIM_PRESCALE_SHIFT) |
+ (dev->hs_cfg->time_p << TIM_P_SHIFT) |
+ (dev->hs_cfg->no_div << TIM_NO_DIV_SHIFT) |
+ (dev->hs_cfg->time_div << TIM_DIV_SHIFT),
+ dev->base + TIM_OFFSET);
+
+ writel((dev->hs_cfg->hs_hold << HSTIM_HS_HOLD_SHIFT) |
+ (dev->hs_cfg->hs_high_phase << HSTIM_HS_HIGH_PHASE_SHIFT) |
+ (dev->hs_cfg->hs_setup << HSTIM_HS_SETUP_SHIFT),
+ dev->base + HSTIM_OFFSET);
+
+ writel(readl(dev->base + HSTIM_OFFSET) | HSTIM_HS_MODE_MASK,
+ dev->base + HSTIM_OFFSET);
+}
+
+static int bcm_kona_i2c_switch_to_hs(struct bcm_kona_i2c_dev *dev)
+{
+ int rc;
+
+ /* Send mastercode at standard speed */
+ rc = bcm_kona_i2c_write_byte(dev, MASTERCODE, 1);
+ if (rc < 0) {
+ pr_err("High speed handshake failed\n");
+ return rc;
+ }
+
+ /* Configure external clock to higher frequency */
+ rc = clk_set_rate(dev->external_clk, HS_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ /* Reconfigure internal dividers */
+ bcm_kona_i2c_config_timing_hs(dev);
+
+ /* Send a restart command */
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+ if (rc < 0)
+ dev_err(dev->device, "High speed restart command failed\n");
+
+ return rc;
+}
+
+static int bcm_kona_i2c_switch_to_std(struct bcm_kona_i2c_dev *dev)
+{
+ int rc;
+
+ /* Reconfigure internal dividers */
+ bcm_kona_i2c_config_timing(dev);
+
+ /* Configure external clock to lower frequency */
+ rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ }
+
+ return rc;
+}
+
+/* Master transfer function */
+static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
+ struct i2c_msg msgs[], int num)
+{
+ struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter);
+ struct i2c_msg *pmsg;
+ int rc = 0;
+ int i;
+
+ rc = clk_prepare_enable(dev->external_clk);
+ if (rc) {
+ dev_err(dev->device, "%s: peri clock enable failed. err %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ /* Enable pad output */
+ writel(0, dev->base + PADCTL_OFFSET);
+
+ /* Enable internal clocks */
+ bcm_kona_i2c_enable_clock(dev);
+
+ /* Send start command */
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
+ if (rc < 0) {
+ dev_err(dev->device, "Start command failed rc = %d\n", rc);
+ goto xfer_disable_pad;
+ }
+
+ /* Switch to high speed if applicable */
+ if (dev->hs_cfg) {
+ rc = bcm_kona_i2c_switch_to_hs(dev);
+ if (rc < 0)
+ goto xfer_send_stop;
+ }
+
+ /* Loop through all messages */
+ for (i = 0; i < num; i++) {
+ pmsg = &msgs[i];
+
+ /* Send restart for subsequent messages */
+ if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+ if (rc < 0) {
+ dev_err(dev->device,
+ "restart cmd failed rc = %d\n", rc);
+ goto xfer_send_stop;
+ }
+ }
+
+ /* Send slave address */
+ if (!(pmsg->flags & I2C_M_NOSTART)) {
+ rc = bcm_kona_i2c_do_addr(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device,
+ "NAK from addr %2.2x msg#%d rc = %d\n",
+ pmsg->addr, i, rc);
+ goto xfer_send_stop;
+ }
+ }
+
+ /* Perform data transfer */
+ if (pmsg->flags & I2C_M_RD) {
+ rc = bcm_kona_i2c_read_fifo(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device, "read failure\n");
+ goto xfer_send_stop;
+ }
+ } else {
+ rc = bcm_kona_i2c_write_fifo(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device, "write failure");
+ goto xfer_send_stop;
+ }
+ }
+ }
+
+ rc = num;
+
+xfer_send_stop:
+ /* Send a STOP command */
+ bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
+
+ /* Return from high speed if applicable */
+ if (dev->hs_cfg) {
+ int hs_rc = bcm_kona_i2c_switch_to_std(dev);
+
+ if (hs_rc)
+ rc = hs_rc;
+ }
+
+xfer_disable_pad:
+ /* Disable pad output */
+ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+ /* Stop internal clock */
+ bcm_kona_i2c_disable_clock(dev);
+
+ clk_disable_unprepare(dev->external_clk);
+
+ return rc;
+}
+
+static uint32_t bcm_kona_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
+ I2C_FUNC_NOSTART;
+}
+
+static const struct i2c_algorithm bcm_algo = {
+ .master_xfer = bcm_kona_i2c_xfer,
+ .functionality = bcm_kona_i2c_functionality,
+};
+
+static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
+{
+ unsigned int bus_speed;
+ int ret = of_property_read_u32(dev->device->of_node, "clock-frequency",
+ &bus_speed);
+ if (ret < 0) {
+ dev_err(dev->device, "missing clock-frequency property\n");
+ return -ENODEV;
+ }
+
+ switch (bus_speed) {
+ case 100000:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+ break;
+ case 400000:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
+ break;
+ case 1000000:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
+ break;
+ case 3400000:
+ /* Send mastercode at 100k */
+ dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+ dev->hs_cfg = &hs_cfg_table[BCM_SPD_3P4MHZ];
+ break;
+ default:
+ pr_err("%d hz bus speed not supported\n", bus_speed);
+ pr_err("Valid speeds are 100khz, 400khz, 1mhz, and 3.4mhz\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int bcm_kona_i2c_probe(struct platform_device *pdev)
+{
+ int rc = 0;
+ struct bcm_kona_i2c_dev *dev;
+ struct i2c_adapter *adap;
+ struct resource *iomem;
+
+ /* Allocate memory for private data structure */
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, dev);
+ dev->device = &pdev->dev;
+ init_completion(&dev->done);
+
+ /* Map hardware registers */
+ iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dev->base = devm_ioremap_resource(dev->device, iomem);
+ if (IS_ERR(dev->base))
+ return -ENOMEM;
+
+ /* Get and enable external clock */
+ dev->external_clk = devm_clk_get(dev->device, NULL);
+ if (IS_ERR(dev->external_clk)) {
+ dev_err(dev->device, "couldn't get clock\n");
+ return -ENODEV;
+ }
+
+ rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ rc = clk_prepare_enable(dev->external_clk);
+ if (rc) {
+ dev_err(dev->device, "couldn't enable clock\n");
+ return rc;
+ }
+
+ /* Parse bus speed */
+ rc = bcm_kona_i2c_assign_bus_speed(dev);
+ if (rc)
+ goto probe_disable_clk;
+
+ /* Enable internal clocks */
+ bcm_kona_i2c_enable_clock(dev);
+
+ /* Configure internal dividers */
+ bcm_kona_i2c_config_timing(dev);
+
+ /* Disable timeout */
+ writel(0, dev->base + TOUT_OFFSET);
+
+ /* Enable autosense */
+ bcm_kona_i2c_enable_autosense(dev);
+
+ /* Enable TX FIFO */
+ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+ dev->base + TXFCR_OFFSET);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ /* Clear all pending interrupts */
+ writel(ISR_CMDBUSY_MASK |
+ ISR_READ_COMPLETE_MASK |
+ ISR_SES_DONE_MASK |
+ ISR_ERR_MASK |
+ ISR_TXFIFOEMPTY_MASK |
+ ISR_NOACK_MASK,
+ dev->base + ISR_OFFSET);
+
+ /* Get the interrupt number */
+ dev->irq = platform_get_irq(pdev, 0);
+ if (dev->irq < 0) {
+ dev_err(dev->device, "no irq resource\n");
+ rc = -ENODEV;
+ goto probe_disable_clk;
+ }
+
+ /* register the ISR handler */
+ rc = devm_request_irq(&pdev->dev, dev->irq, bcm_kona_i2c_isr,
+ IRQF_SHARED, pdev->name, dev);
+ if (rc) {
+ dev_err(dev->device, "failed to request irq %i\n", dev->irq);
+ goto probe_disable_clk;
+ }
+
+ /* Enable the controller but leave it idle */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+ /* Disable pad output */
+ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+ /* Disable internal clock */
+ bcm_kona_i2c_disable_clock(dev);
+
+ /* Disable external clock */
+ clk_disable_unprepare(dev->external_clk);
+
+ /* Add the i2c adapter */
+ adap = &dev->adapter;
+ i2c_set_adapdata(adap, dev);
+ adap->owner = THIS_MODULE;
+ strlcpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name));
+ adap->algo = &bcm_algo;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+
+ rc = i2c_add_adapter(adap);
+ if (rc) {
+ dev_err(dev->device, "failed to add adapter\n");
+ return rc;
+ }
+
+ dev_info(dev->device, "device registered successfully\n");
+
+ return 0;
+
+probe_disable_clk:
+ bcm_kona_i2c_disable_clock(dev);
+ clk_disable_unprepare(dev->external_clk);
+
+ return rc;
+}
+
+static int bcm_kona_i2c_remove(struct platform_device *pdev)
+{
+ struct bcm_kona_i2c_dev *dev = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&dev->adapter);
+
+ return 0;
+}
+
+static const struct of_device_id bcm_kona_i2c_of_match[] = {
+ {.compatible = "brcm,kona-i2c",},
+ {},
+};
+MODULE_DEVICE_TABLE(of, bcm_kona_i2c_of_match);
+
+static struct platform_driver bcm_kona_i2c_driver = {
+ .driver = {
+ .name = "bcm-kona-i2c",
+ .of_match_table = bcm_kona_i2c_of_match,
+ },
+ .probe = bcm_kona_i2c_probe,
+ .remove = bcm_kona_i2c_remove,
+};
+module_platform_driver(bcm_kona_i2c_driver);
+
+MODULE_AUTHOR("Tim Kryger <tkryger@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom Kona I2C Driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff