/* * 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 #include #include #include #include #include #include #include #include #include /* 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 "); MODULE_DESCRIPTION("Broadcom Kona I2C Driver"); MODULE_LICENSE("GPL v2");