| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Manivannan Sadhasivam | 2089 | 99.67% | 1 | 50.00% |
| Parthiban Nallathambi | 7 | 0.33% | 1 | 50.00% |
| Total | 2096 | 2 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Actions Semiconductor Owl SoC's I2C driver * * Copyright (c) 2014 Actions Semi Inc. * Author: David Liu <liuwei@actions-semi.com> * * Copyright (c) 2018 Linaro Ltd. * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_device.h> /* I2C registers */ #define OWL_I2C_REG_CTL 0x0000 #define OWL_I2C_REG_CLKDIV 0x0004 #define OWL_I2C_REG_STAT 0x0008 #define OWL_I2C_REG_ADDR 0x000C #define OWL_I2C_REG_TXDAT 0x0010 #define OWL_I2C_REG_RXDAT 0x0014 #define OWL_I2C_REG_CMD 0x0018 #define OWL_I2C_REG_FIFOCTL 0x001C #define OWL_I2C_REG_FIFOSTAT 0x0020 #define OWL_I2C_REG_DATCNT 0x0024 #define OWL_I2C_REG_RCNT 0x0028 /* I2Cx_CTL Bit Mask */ #define OWL_I2C_CTL_RB BIT(1) #define OWL_I2C_CTL_GBCC(x) (((x) & 0x3) << 2) #define OWL_I2C_CTL_GBCC_NONE OWL_I2C_CTL_GBCC(0) #define OWL_I2C_CTL_GBCC_START OWL_I2C_CTL_GBCC(1) #define OWL_I2C_CTL_GBCC_STOP OWL_I2C_CTL_GBCC(2) #define OWL_I2C_CTL_GBCC_RSTART OWL_I2C_CTL_GBCC(3) #define OWL_I2C_CTL_IRQE BIT(5) #define OWL_I2C_CTL_EN BIT(7) #define OWL_I2C_CTL_AE BIT(8) #define OWL_I2C_CTL_SHSM BIT(10) #define OWL_I2C_DIV_FACTOR(x) ((x) & 0xff) /* I2Cx_STAT Bit Mask */ #define OWL_I2C_STAT_RACK BIT(0) #define OWL_I2C_STAT_BEB BIT(1) #define OWL_I2C_STAT_IRQP BIT(2) #define OWL_I2C_STAT_LAB BIT(3) #define OWL_I2C_STAT_STPD BIT(4) #define OWL_I2C_STAT_STAD BIT(5) #define OWL_I2C_STAT_BBB BIT(6) #define OWL_I2C_STAT_TCB BIT(7) #define OWL_I2C_STAT_LBST BIT(8) #define OWL_I2C_STAT_SAMB BIT(9) #define OWL_I2C_STAT_SRGC BIT(10) /* I2Cx_CMD Bit Mask */ #define OWL_I2C_CMD_SBE BIT(0) #define OWL_I2C_CMD_RBE BIT(4) #define OWL_I2C_CMD_DE BIT(8) #define OWL_I2C_CMD_NS BIT(9) #define OWL_I2C_CMD_SE BIT(10) #define OWL_I2C_CMD_MSS BIT(11) #define OWL_I2C_CMD_WRS BIT(12) #define OWL_I2C_CMD_SECL BIT(15) #define OWL_I2C_CMD_AS(x) (((x) & 0x7) << 1) #define OWL_I2C_CMD_SAS(x) (((x) & 0x7) << 5) /* I2Cx_FIFOCTL Bit Mask */ #define OWL_I2C_FIFOCTL_NIB BIT(0) #define OWL_I2C_FIFOCTL_RFR BIT(1) #define OWL_I2C_FIFOCTL_TFR BIT(2) /* I2Cc_FIFOSTAT Bit Mask */ #define OWL_I2C_FIFOSTAT_RNB BIT(1) #define OWL_I2C_FIFOSTAT_RFE BIT(2) #define OWL_I2C_FIFOSTAT_TFF BIT(5) #define OWL_I2C_FIFOSTAT_TFD GENMASK(23, 16) #define OWL_I2C_FIFOSTAT_RFD GENMASK(15, 8) /* I2C bus timeout */ #define OWL_I2C_TIMEOUT msecs_to_jiffies(4 * 1000) #define OWL_I2C_MAX_RETRIES 50 #define OWL_I2C_DEF_SPEED_HZ 100000 #define OWL_I2C_MAX_SPEED_HZ 400000 struct owl_i2c_dev { struct i2c_adapter adap; struct i2c_msg *msg; struct completion msg_complete; struct clk *clk; spinlock_t lock; void __iomem *base; unsigned long clk_rate; u32 bus_freq; u32 msg_ptr; int err; }; static void owl_i2c_update_reg(void __iomem *reg, unsigned int val, bool state) { unsigned int regval; regval = readl(reg); if (state) regval |= val; else regval &= ~val; writel(regval, reg); } static void owl_i2c_reset(struct owl_i2c_dev *i2c_dev) { owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, OWL_I2C_CTL_EN, false); mdelay(1); owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, OWL_I2C_CTL_EN, true); /* Clear status registers */ writel(0, i2c_dev->base + OWL_I2C_REG_STAT); } static int owl_i2c_reset_fifo(struct owl_i2c_dev *i2c_dev) { unsigned int val, timeout = 0; /* Reset FIFO */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL, OWL_I2C_FIFOCTL_RFR | OWL_I2C_FIFOCTL_TFR, true); /* Wait 50ms for FIFO reset complete */ do { val = readl(i2c_dev->base + OWL_I2C_REG_FIFOCTL); if (!(val & (OWL_I2C_FIFOCTL_RFR | OWL_I2C_FIFOCTL_TFR))) break; usleep_range(500, 1000); } while (timeout++ < OWL_I2C_MAX_RETRIES); if (timeout > OWL_I2C_MAX_RETRIES) { dev_err(&i2c_dev->adap.dev, "FIFO reset timeout\n"); return -ETIMEDOUT; } return 0; } static void owl_i2c_set_freq(struct owl_i2c_dev *i2c_dev) { unsigned int val; val = DIV_ROUND_UP(i2c_dev->clk_rate, i2c_dev->bus_freq * 16); /* Set clock divider factor */ writel(OWL_I2C_DIV_FACTOR(val), i2c_dev->base + OWL_I2C_REG_CLKDIV); } static irqreturn_t owl_i2c_interrupt(int irq, void *_dev) { struct owl_i2c_dev *i2c_dev = _dev; struct i2c_msg *msg = i2c_dev->msg; unsigned long flags; unsigned int stat, fifostat; spin_lock_irqsave(&i2c_dev->lock, flags); i2c_dev->err = 0; /* Handle NACK from slave */ fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT); if (fifostat & OWL_I2C_FIFOSTAT_RNB) { i2c_dev->err = -ENXIO; goto stop; } /* Handle bus error */ stat = readl(i2c_dev->base + OWL_I2C_REG_STAT); if (stat & OWL_I2C_STAT_BEB) { i2c_dev->err = -EIO; goto stop; } /* Handle FIFO read */ if (msg->flags & I2C_M_RD) { while ((readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) & OWL_I2C_FIFOSTAT_RFE) && i2c_dev->msg_ptr < msg->len) { msg->buf[i2c_dev->msg_ptr++] = readl(i2c_dev->base + OWL_I2C_REG_RXDAT); } } else { /* Handle the remaining bytes which were not sent */ while (!(readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) & OWL_I2C_FIFOSTAT_TFF) && i2c_dev->msg_ptr < msg->len) { writel(msg->buf[i2c_dev->msg_ptr++], i2c_dev->base + OWL_I2C_REG_TXDAT); } } stop: /* Clear pending interrupts */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT, OWL_I2C_STAT_IRQP, true); complete_all(&i2c_dev->msg_complete); spin_unlock_irqrestore(&i2c_dev->lock, flags); return IRQ_HANDLED; } static u32 owl_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static int owl_i2c_check_bus_busy(struct i2c_adapter *adap) { struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap); unsigned long timeout; /* Check for Bus busy */ timeout = jiffies + OWL_I2C_TIMEOUT; while (readl(i2c_dev->base + OWL_I2C_REG_STAT) & OWL_I2C_STAT_BBB) { if (time_after(jiffies, timeout)) { dev_err(&adap->dev, "Bus busy timeout\n"); return -ETIMEDOUT; } } return 0; } static int owl_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap); struct i2c_msg *msg; unsigned long time_left, flags; unsigned int i2c_cmd, val; unsigned int addr; int ret, idx; spin_lock_irqsave(&i2c_dev->lock, flags); /* Reset I2C controller */ owl_i2c_reset(i2c_dev); /* Set bus frequency */ owl_i2c_set_freq(i2c_dev); /* * Spinlock should be released before calling reset FIFO and * bus busy check since those functions may sleep */ spin_unlock_irqrestore(&i2c_dev->lock, flags); /* Reset FIFO */ ret = owl_i2c_reset_fifo(i2c_dev); if (ret) goto unlocked_err_exit; /* Check for bus busy */ ret = owl_i2c_check_bus_busy(adap); if (ret) goto unlocked_err_exit; spin_lock_irqsave(&i2c_dev->lock, flags); /* Check for Arbitration lost */ val = readl(i2c_dev->base + OWL_I2C_REG_STAT); if (val & OWL_I2C_STAT_LAB) { val &= ~OWL_I2C_STAT_LAB; writel(val, i2c_dev->base + OWL_I2C_REG_STAT); ret = -EAGAIN; goto err_exit; } reinit_completion(&i2c_dev->msg_complete); /* Enable I2C controller interrupt */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, OWL_I2C_CTL_IRQE, true); /* * Select: FIFO enable, Master mode, Stop enable, Data count enable, * Send start bit */ i2c_cmd = OWL_I2C_CMD_SECL | OWL_I2C_CMD_MSS | OWL_I2C_CMD_SE | OWL_I2C_CMD_NS | OWL_I2C_CMD_DE | OWL_I2C_CMD_SBE; /* Handle repeated start condition */ if (num > 1) { /* Set internal address length and enable repeated start */ i2c_cmd |= OWL_I2C_CMD_AS(msgs[0].len + 1) | OWL_I2C_CMD_SAS(1) | OWL_I2C_CMD_RBE; /* Write slave address */ addr = i2c_8bit_addr_from_msg(&msgs[0]); writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT); /* Write internal register address */ for (idx = 0; idx < msgs[0].len; idx++) writel(msgs[0].buf[idx], i2c_dev->base + OWL_I2C_REG_TXDAT); msg = &msgs[1]; } else { /* Set address length */ i2c_cmd |= OWL_I2C_CMD_AS(1); msg = &msgs[0]; } i2c_dev->msg = msg; i2c_dev->msg_ptr = 0; /* Set data count for the message */ writel(msg->len, i2c_dev->base + OWL_I2C_REG_DATCNT); addr = i2c_8bit_addr_from_msg(msg); writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT); if (!(msg->flags & I2C_M_RD)) { /* Write data to FIFO */ for (idx = 0; idx < msg->len; idx++) { /* Check for FIFO full */ if (readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) & OWL_I2C_FIFOSTAT_TFF) break; writel(msg->buf[idx], i2c_dev->base + OWL_I2C_REG_TXDAT); } i2c_dev->msg_ptr = idx; } /* Ignore the NACK if needed */ if (msg->flags & I2C_M_IGNORE_NAK) owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL, OWL_I2C_FIFOCTL_NIB, true); else owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL, OWL_I2C_FIFOCTL_NIB, false); /* Start the transfer */ writel(i2c_cmd, i2c_dev->base + OWL_I2C_REG_CMD); spin_unlock_irqrestore(&i2c_dev->lock, flags); time_left = wait_for_completion_timeout(&i2c_dev->msg_complete, adap->timeout); spin_lock_irqsave(&i2c_dev->lock, flags); if (time_left == 0) { dev_err(&adap->dev, "Transaction timed out\n"); /* Send stop condition and release the bus */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, OWL_I2C_CTL_GBCC_STOP | OWL_I2C_CTL_RB, true); ret = -ETIMEDOUT; goto err_exit; } ret = i2c_dev->err < 0 ? i2c_dev->err : num; err_exit: spin_unlock_irqrestore(&i2c_dev->lock, flags); unlocked_err_exit: /* Disable I2C controller */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, OWL_I2C_CTL_EN, false); return ret; } static const struct i2c_algorithm owl_i2c_algorithm = { .master_xfer = owl_i2c_master_xfer, .functionality = owl_i2c_func, }; static const struct i2c_adapter_quirks owl_i2c_quirks = { .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST, .max_read_len = 240, .max_write_len = 240, .max_comb_1st_msg_len = 6, .max_comb_2nd_msg_len = 240, }; static int owl_i2c_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct owl_i2c_dev *i2c_dev; struct resource *res; int ret, irq; i2c_dev = devm_kzalloc(dev, sizeof(*i2c_dev), GFP_KERNEL); if (!i2c_dev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c_dev->base = devm_ioremap_resource(dev, res); if (IS_ERR(i2c_dev->base)) return PTR_ERR(i2c_dev->base); irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(dev, "failed to get IRQ number\n"); return irq; } if (of_property_read_u32(dev->of_node, "clock-frequency", &i2c_dev->bus_freq)) i2c_dev->bus_freq = OWL_I2C_DEF_SPEED_HZ; /* We support only frequencies of 100k and 400k for now */ if (i2c_dev->bus_freq != OWL_I2C_DEF_SPEED_HZ && i2c_dev->bus_freq != OWL_I2C_MAX_SPEED_HZ) { dev_err(dev, "invalid clock-frequency %d\n", i2c_dev->bus_freq); return -EINVAL; } i2c_dev->clk = devm_clk_get(dev, NULL); if (IS_ERR(i2c_dev->clk)) { dev_err(dev, "failed to get clock\n"); return PTR_ERR(i2c_dev->clk); } ret = clk_prepare_enable(i2c_dev->clk); if (ret) return ret; i2c_dev->clk_rate = clk_get_rate(i2c_dev->clk); if (!i2c_dev->clk_rate) { dev_err(dev, "input clock rate should not be zero\n"); ret = -EINVAL; goto disable_clk; } init_completion(&i2c_dev->msg_complete); spin_lock_init(&i2c_dev->lock); i2c_dev->adap.owner = THIS_MODULE; i2c_dev->adap.algo = &owl_i2c_algorithm; i2c_dev->adap.timeout = OWL_I2C_TIMEOUT; i2c_dev->adap.quirks = &owl_i2c_quirks; i2c_dev->adap.dev.parent = dev; i2c_dev->adap.dev.of_node = dev->of_node; snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name), "%s", "OWL I2C adapter"); i2c_set_adapdata(&i2c_dev->adap, i2c_dev); platform_set_drvdata(pdev, i2c_dev); ret = devm_request_irq(dev, irq, owl_i2c_interrupt, 0, pdev->name, i2c_dev); if (ret) { dev_err(dev, "failed to request irq %d\n", irq); goto disable_clk; } return i2c_add_adapter(&i2c_dev->adap); disable_clk: clk_disable_unprepare(i2c_dev->clk); return ret; } static const struct of_device_id owl_i2c_of_match[] = { { .compatible = "actions,s700-i2c" }, { .compatible = "actions,s900-i2c" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, owl_i2c_of_match); static struct platform_driver owl_i2c_driver = { .probe = owl_i2c_probe, .driver = { .name = "owl-i2c", .of_match_table = of_match_ptr(owl_i2c_of_match), }, }; module_platform_driver(owl_i2c_driver); MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>"); MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>"); MODULE_DESCRIPTION("Actions Semiconductor Owl SoC's I2C driver"); MODULE_LICENSE("GPL");
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