/* * Driver for the i2c controller on the Marvell line of host bridges * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family). * * Author: Mark A. Greer * * 2005 (c) MontaVista, Software, Inc. This file is licensed under * the terms of the GNU General Public License version 2. This program * is licensed "as is" without any warranty of any kind, whether express * or implied. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Register defines */ #define MV64XXX_I2C_REG_SLAVE_ADDR 0x00 #define MV64XXX_I2C_REG_DATA 0x04 #define MV64XXX_I2C_REG_CONTROL 0x08 #define MV64XXX_I2C_REG_STATUS 0x0c #define MV64XXX_I2C_REG_BAUD 0x0c #define MV64XXX_I2C_REG_EXT_SLAVE_ADDR 0x10 #define MV64XXX_I2C_REG_SOFT_RESET 0x1c #define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004 #define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008 #define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010 #define MV64XXX_I2C_REG_CONTROL_START 0x00000020 #define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040 #define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080 /* Ctlr status values */ #define MV64XXX_I2C_STATUS_BUS_ERR 0x00 #define MV64XXX_I2C_STATUS_MAST_START 0x08 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 #define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 #define MV64XXX_I2C_STATUS_NO_STATUS 0xf8 /* Driver states */ enum { MV64XXX_I2C_STATE_INVALID, MV64XXX_I2C_STATE_IDLE, MV64XXX_I2C_STATE_WAITING_FOR_START_COND, MV64XXX_I2C_STATE_WAITING_FOR_RESTART, MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK, MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK, MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK, MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA, }; /* Driver actions */ enum { MV64XXX_I2C_ACTION_INVALID, MV64XXX_I2C_ACTION_CONTINUE, MV64XXX_I2C_ACTION_SEND_START, MV64XXX_I2C_ACTION_SEND_RESTART, MV64XXX_I2C_ACTION_SEND_ADDR_1, MV64XXX_I2C_ACTION_SEND_ADDR_2, MV64XXX_I2C_ACTION_SEND_DATA, MV64XXX_I2C_ACTION_RCV_DATA, MV64XXX_I2C_ACTION_RCV_DATA_STOP, MV64XXX_I2C_ACTION_SEND_STOP, }; struct mv64xxx_i2c_data { int irq; u32 state; u32 action; u32 aborting; u32 cntl_bits; void __iomem *reg_base; u32 addr1; u32 addr2; u32 bytes_left; u32 byte_posn; u32 send_stop; u32 block; int rc; u32 freq_m; u32 freq_n; #if defined(CONFIG_HAVE_CLK) struct clk *clk; #endif wait_queue_head_t waitq; spinlock_t lock; struct i2c_msg *msg; struct i2c_adapter adapter; }; static void mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg) { u32 dir = 0; drv_data->msg = msg; drv_data->byte_posn = 0; drv_data->bytes_left = msg->len; drv_data->aborting = 0; drv_data->rc = 0; drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK | MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN; if (msg->flags & I2C_M_RD) dir = 1; if (msg->flags & I2C_M_TEN) { drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir; drv_data->addr2 = (u32)msg->addr & 0xff; } else { drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir; drv_data->addr2 = 0; } } /* ***************************************************************************** * * Finite State Machine & Interrupt Routines * ***************************************************************************** */ /* Reset hardware and initialize FSM */ static void mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data) { writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET); writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)), drv_data->reg_base + MV64XXX_I2C_REG_BAUD); writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR); writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR); writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->state = MV64XXX_I2C_STATE_IDLE; } static void mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) { /* * If state is idle, then this is likely the remnants of an old * operation that driver has given up on or the user has killed. * If so, issue the stop condition and go to idle. */ if (drv_data->state == MV64XXX_I2C_STATE_IDLE) { drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; return; } /* The status from the ctlr [mostly] tells us what to do next */ switch (status) { /* Start condition interrupt */ case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */ case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */ drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK; break; /* Performing a write */ case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */ if (drv_data->msg->flags & I2C_M_TEN) { drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; break; } /* FALLTHRU */ case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */ case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */ if ((drv_data->bytes_left == 0) || (drv_data->aborting && (drv_data->byte_posn != 0))) { if (drv_data->send_stop) { drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; drv_data->state = MV64XXX_I2C_STATE_IDLE; } else { drv_data->action = MV64XXX_I2C_ACTION_SEND_RESTART; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_RESTART; } } else { drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK; drv_data->bytes_left--; } break; /* Performing a read */ case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */ if (drv_data->msg->flags & I2C_M_TEN) { drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; break; } /* FALLTHRU */ case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */ if (drv_data->bytes_left == 0) { drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; drv_data->state = MV64XXX_I2C_STATE_IDLE; break; } /* FALLTHRU */ case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */ if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK) drv_data->action = MV64XXX_I2C_ACTION_CONTINUE; else { drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA; drv_data->bytes_left--; } drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA; if ((drv_data->bytes_left == 1) || drv_data->aborting) drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK; break; case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP; drv_data->state = MV64XXX_I2C_STATE_IDLE; break; case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ /* Doesn't seem to be a device at other end */ drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; drv_data->state = MV64XXX_I2C_STATE_IDLE; drv_data->rc = -ENODEV; break; default: dev_err(&drv_data->adapter.dev, "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, " "status: 0x%x, addr: 0x%x, flags: 0x%x\n", drv_data->state, status, drv_data->msg->addr, drv_data->msg->flags); drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; mv64xxx_i2c_hw_init(drv_data); drv_data->rc = -EIO; } } static void mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) { switch(drv_data->action) { case MV64XXX_I2C_ACTION_SEND_RESTART: drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_START; drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->block = 0; wake_up(&drv_data->waitq); break; case MV64XXX_I2C_ACTION_CONTINUE: writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); break; case MV64XXX_I2C_ACTION_SEND_START: writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); break; case MV64XXX_I2C_ACTION_SEND_ADDR_1: writel(drv_data->addr1, drv_data->reg_base + MV64XXX_I2C_REG_DATA); writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); break; case MV64XXX_I2C_ACTION_SEND_ADDR_2: writel(drv_data->addr2, drv_data->reg_base + MV64XXX_I2C_REG_DATA); writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); break; case MV64XXX_I2C_ACTION_SEND_DATA: writel(drv_data->msg->buf[drv_data->byte_posn++], drv_data->reg_base + MV64XXX_I2C_REG_DATA); writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); break; case MV64XXX_I2C_ACTION_RCV_DATA: drv_data->msg->buf[drv_data->byte_posn++] = readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA); writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); break; case MV64XXX_I2C_ACTION_RCV_DATA_STOP: drv_data->msg->buf[drv_data->byte_posn++] = readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA); drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->block = 0; wake_up(&drv_data->waitq); break; case MV64XXX_I2C_ACTION_INVALID: default: dev_err(&drv_data->adapter.dev, "mv64xxx_i2c_do_action: Invalid action: %d\n", drv_data->action); drv_data->rc = -EIO; /* FALLTHRU */ case MV64XXX_I2C_ACTION_SEND_STOP: drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->block = 0; wake_up(&drv_data->waitq); break; } } static irqreturn_t mv64xxx_i2c_intr(int irq, void *dev_id) { struct mv64xxx_i2c_data *drv_data = dev_id; unsigned long flags; u32 status; irqreturn_t rc = IRQ_NONE; spin_lock_irqsave(&drv_data->lock, flags); while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) & MV64XXX_I2C_REG_CONTROL_IFLG) { status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS); mv64xxx_i2c_fsm(drv_data, status); mv64xxx_i2c_do_action(drv_data); rc = IRQ_HANDLED; } spin_unlock_irqrestore(&drv_data->lock, flags); return rc; } /* ***************************************************************************** * * I2C Msg Execution Routines * ***************************************************************************** */ static void mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) { long time_left; unsigned long flags; char abort = 0; time_left = wait_event_timeout(drv_data->waitq, !drv_data->block, drv_data->adapter.timeout); spin_lock_irqsave(&drv_data->lock, flags); if (!time_left) { /* Timed out */ drv_data->rc = -ETIMEDOUT; abort = 1; } else if (time_left < 0) { /* Interrupted/Error */ drv_data->rc = time_left; /* errno value */ abort = 1; } if (abort && drv_data->block) { drv_data->aborting = 1; spin_unlock_irqrestore(&drv_data->lock, flags); time_left = wait_event_timeout(drv_data->waitq, !drv_data->block, drv_data->adapter.timeout); if ((time_left <= 0) && drv_data->block) { drv_data->state = MV64XXX_I2C_STATE_IDLE; dev_err(&drv_data->adapter.dev, "mv64xxx: I2C bus locked, block: %d, " "time_left: %d\n", drv_data->block, (int)time_left); mv64xxx_i2c_hw_init(drv_data); } } else spin_unlock_irqrestore(&drv_data->lock, flags); } static int mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg, int is_first, int is_last) { unsigned long flags; spin_lock_irqsave(&drv_data->lock, flags); mv64xxx_i2c_prepare_for_io(drv_data, msg); if (is_first) { drv_data->action = MV64XXX_I2C_ACTION_SEND_START; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND; } else { drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1; drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK; } drv_data->send_stop = is_last; drv_data->block = 1; mv64xxx_i2c_do_action(drv_data); spin_unlock_irqrestore(&drv_data->lock, flags); mv64xxx_i2c_wait_for_completion(drv_data); return drv_data->rc; } /* ***************************************************************************** * * I2C Core Support Routines (Interface to higher level I2C code) * ***************************************************************************** */ static u32 mv64xxx_i2c_functionality(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL; } static int mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); int i, rc; for (i = 0; i < num; i++) { rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i], i == 0, i + 1 == num); if (rc < 0) return rc; } return num; } static const struct i2c_algorithm mv64xxx_i2c_algo = { .master_xfer = mv64xxx_i2c_xfer, .functionality = mv64xxx_i2c_functionality, }; /* ***************************************************************************** * * Driver Interface & Early Init Routines * ***************************************************************************** */ #ifdef CONFIG_OF static int mv64xxx_calc_freq(const int tclk, const int n, const int m) { return tclk / (10 * (m + 1) * (2 << n)); } static bool mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n, u32 *best_m) { int freq, delta, best_delta = INT_MAX; int m, n; for (n = 0; n <= 7; n++) for (m = 0; m <= 15; m++) { freq = mv64xxx_calc_freq(tclk, n, m); delta = req_freq - freq; if (delta >= 0 && delta < best_delta) { *best_m = m; *best_n = n; best_delta = delta; } if (best_delta == 0) return true; } if (best_delta == INT_MAX) return false; return true; } static int mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, struct device_node *np) { u32 bus_freq, tclk; int rc = 0; /* CLK is mandatory when using DT to describe the i2c bus. We * need to know tclk in order to calculate bus clock * factors. */ #if !defined(CONFIG_HAVE_CLK) /* Have OF but no CLK */ return -ENODEV; #else if (IS_ERR(drv_data->clk)) { rc = -ENODEV; goto out; } tclk = clk_get_rate(drv_data->clk); of_property_read_u32(np, "clock-frequency", &bus_freq); if (!mv64xxx_find_baud_factors(bus_freq, tclk, &drv_data->freq_n, &drv_data->freq_m)) { rc = -EINVAL; goto out; } drv_data->irq = irq_of_parse_and_map(np, 0); /* Its not yet defined how timeouts will be specified in device tree. * So hard code the value to 1 second. */ drv_data->adapter.timeout = HZ; out: return rc; #endif } #else /* CONFIG_OF */ static int mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, struct device_node *np) { return -ENODEV; } #endif /* CONFIG_OF */ static int mv64xxx_i2c_probe(struct platform_device *pd) { struct mv64xxx_i2c_data *drv_data; struct mv64xxx_i2c_pdata *pdata = pd->dev.platform_data; struct resource *r; int rc; if ((!pdata && !pd->dev.of_node)) return -ENODEV; drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data), GFP_KERNEL); if (!drv_data) return -ENOMEM; r = platform_get_resource(pd, IORESOURCE_MEM, 0); drv_data->reg_base = devm_ioremap_resource(&pd->dev, r); if (IS_ERR(drv_data->reg_base)) return PTR_ERR(drv_data->reg_base); strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter", sizeof(drv_data->adapter.name)); init_waitqueue_head(&drv_data->waitq); spin_lock_init(&drv_data->lock); #if defined(CONFIG_HAVE_CLK) /* Not all platforms have a clk */ drv_data->clk = devm_clk_get(&pd->dev, NULL); if (!IS_ERR(drv_data->clk)) { clk_prepare(drv_data->clk); clk_enable(drv_data->clk); } #endif if (pdata) { drv_data->freq_m = pdata->freq_m; drv_data->freq_n = pdata->freq_n; drv_data->irq = platform_get_irq(pd, 0); drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout); } else if (pd->dev.of_node) { rc = mv64xxx_of_config(drv_data, pd->dev.of_node); if (rc) goto exit_clk; } if (drv_data->irq < 0) { rc = -ENXIO; goto exit_clk; } drv_data->adapter.dev.parent = &pd->dev; drv_data->adapter.algo = &mv64xxx_i2c_algo; drv_data->adapter.owner = THIS_MODULE; drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; drv_data->adapter.nr = pd->id; drv_data->adapter.dev.of_node = pd->dev.of_node; platform_set_drvdata(pd, drv_data); i2c_set_adapdata(&drv_data->adapter, drv_data); mv64xxx_i2c_hw_init(drv_data); rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0, MV64XXX_I2C_CTLR_NAME, drv_data); if (rc) { dev_err(&drv_data->adapter.dev, "mv64xxx: Can't register intr handler irq%d: %d\n", drv_data->irq, rc); goto exit_clk; } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) { dev_err(&drv_data->adapter.dev, "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc); goto exit_free_irq; } of_i2c_register_devices(&drv_data->adapter); return 0; exit_free_irq: free_irq(drv_data->irq, drv_data); exit_clk: #if defined(CONFIG_HAVE_CLK) /* Not all platforms have a clk */ if (!IS_ERR(drv_data->clk)) { clk_disable(drv_data->clk); clk_unprepare(drv_data->clk); } #endif return rc; } static int mv64xxx_i2c_remove(struct platform_device *dev) { struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev); i2c_del_adapter(&drv_data->adapter); free_irq(drv_data->irq, drv_data); #if defined(CONFIG_HAVE_CLK) /* Not all platforms have a clk */ if (!IS_ERR(drv_data->clk)) { clk_disable(drv_data->clk); clk_unprepare(drv_data->clk); } #endif return 0; } static const struct of_device_id mv64xxx_i2c_of_match_table[] = { { .compatible = "marvell,mv64xxx-i2c", }, {} }; MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table); static struct platform_driver mv64xxx_i2c_driver = { .probe = mv64xxx_i2c_probe, .remove = mv64xxx_i2c_remove, .driver = { .owner = THIS_MODULE, .name = MV64XXX_I2C_CTLR_NAME, .of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table), }, }; module_platform_driver(mv64xxx_i2c_driver); MODULE_AUTHOR("Mark A. Greer "); MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver"); MODULE_LICENSE("GPL");