// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2012 FUJITSU SEMICONDUCTOR LIMITED */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define WAIT_PCLK(n, rate) \ ndelay(DIV_ROUND_UP(DIV_ROUND_UP(1000000000, rate), n) + 10) /* I2C register address definitions */ #define SYNQUACER_I2C_REG_BSR (0x00 << 2) // Bus Status #define SYNQUACER_I2C_REG_BCR (0x01 << 2) // Bus Control #define SYNQUACER_I2C_REG_CCR (0x02 << 2) // Clock Control #define SYNQUACER_I2C_REG_ADR (0x03 << 2) // Address #define SYNQUACER_I2C_REG_DAR (0x04 << 2) // Data #define SYNQUACER_I2C_REG_CSR (0x05 << 2) // Expansion CS #define SYNQUACER_I2C_REG_FSR (0x06 << 2) // Bus Clock Freq #define SYNQUACER_I2C_REG_BC2R (0x07 << 2) // Bus Control 2 /* I2C register bit definitions */ #define SYNQUACER_I2C_BSR_FBT BIT(0) // First Byte Transfer #define SYNQUACER_I2C_BSR_GCA BIT(1) // General Call Address #define SYNQUACER_I2C_BSR_AAS BIT(2) // Address as Slave #define SYNQUACER_I2C_BSR_TRX BIT(3) // Transfer/Receive #define SYNQUACER_I2C_BSR_LRB BIT(4) // Last Received Bit #define SYNQUACER_I2C_BSR_AL BIT(5) // Arbitration Lost #define SYNQUACER_I2C_BSR_RSC BIT(6) // Repeated Start Cond. #define SYNQUACER_I2C_BSR_BB BIT(7) // Bus Busy #define SYNQUACER_I2C_BCR_INT BIT(0) // Interrupt #define SYNQUACER_I2C_BCR_INTE BIT(1) // Interrupt Enable #define SYNQUACER_I2C_BCR_GCAA BIT(2) // Gen. Call Access Ack. #define SYNQUACER_I2C_BCR_ACK BIT(3) // Acknowledge #define SYNQUACER_I2C_BCR_MSS BIT(4) // Master Slave Select #define SYNQUACER_I2C_BCR_SCC BIT(5) // Start Condition Cont. #define SYNQUACER_I2C_BCR_BEIE BIT(6) // Bus Error Int Enable #define SYNQUACER_I2C_BCR_BER BIT(7) // Bus Error #define SYNQUACER_I2C_CCR_CS_MASK (0x1f) // CCR Clock Period Sel. #define SYNQUACER_I2C_CCR_EN BIT(5) // Enable #define SYNQUACER_I2C_CCR_FM BIT(6) // Speed Mode Select #define SYNQUACER_I2C_CSR_CS_MASK (0x3f) // CSR Clock Period Sel. #define SYNQUACER_I2C_BC2R_SCLL BIT(0) // SCL Low Drive #define SYNQUACER_I2C_BC2R_SDAL BIT(1) // SDA Low Drive #define SYNQUACER_I2C_BC2R_SCLS BIT(4) // SCL Status #define SYNQUACER_I2C_BC2R_SDAS BIT(5) // SDA Status /* PCLK frequency */ #define SYNQUACER_I2C_BUS_CLK_FR(rate) (((rate) / 20000000) + 1) /* STANDARD MODE frequency */ #define SYNQUACER_I2C_CLK_MASTER_STD(rate) \ DIV_ROUND_UP(DIV_ROUND_UP((rate), 100000) - 2, 2) /* FAST MODE frequency */ #define SYNQUACER_I2C_CLK_MASTER_FAST(rate) \ DIV_ROUND_UP((DIV_ROUND_UP((rate), 400000) - 2) * 2, 3) /* (clkrate <= 18000000) */ /* calculate the value of CS bits in CCR register on standard mode */ #define SYNQUACER_I2C_CCR_CS_STD_MAX_18M(rate) \ ((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 65) \ & SYNQUACER_I2C_CCR_CS_MASK) /* calculate the value of CS bits in CSR register on standard mode */ #define SYNQUACER_I2C_CSR_CS_STD_MAX_18M(rate) 0x00 /* calculate the value of CS bits in CCR register on fast mode */ #define SYNQUACER_I2C_CCR_CS_FAST_MAX_18M(rate) \ ((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) \ & SYNQUACER_I2C_CCR_CS_MASK) /* calculate the value of CS bits in CSR register on fast mode */ #define SYNQUACER_I2C_CSR_CS_FAST_MAX_18M(rate) 0x00 /* (clkrate > 18000000) */ /* calculate the value of CS bits in CCR register on standard mode */ #define SYNQUACER_I2C_CCR_CS_STD_MIN_18M(rate) \ ((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 1) \ & SYNQUACER_I2C_CCR_CS_MASK) /* calculate the value of CS bits in CSR register on standard mode */ #define SYNQUACER_I2C_CSR_CS_STD_MIN_18M(rate) \ (((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 1) >> 5) \ & SYNQUACER_I2C_CSR_CS_MASK) /* calculate the value of CS bits in CCR register on fast mode */ #define SYNQUACER_I2C_CCR_CS_FAST_MIN_18M(rate) \ ((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) \ & SYNQUACER_I2C_CCR_CS_MASK) /* calculate the value of CS bits in CSR register on fast mode */ #define SYNQUACER_I2C_CSR_CS_FAST_MIN_18M(rate) \ (((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) >> 5) \ & SYNQUACER_I2C_CSR_CS_MASK) /* min I2C clock frequency 14M */ #define SYNQUACER_I2C_MIN_CLK_RATE (14 * 1000000) /* max I2C clock frequency 200M */ #define SYNQUACER_I2C_MAX_CLK_RATE (200 * 1000000) /* I2C clock frequency 18M */ #define SYNQUACER_I2C_CLK_RATE_18M (18 * 1000000) #define SYNQUACER_I2C_SPEED_FM 400 // Fast Mode #define SYNQUACER_I2C_SPEED_SM 100 // Standard Mode enum i2c_state { STATE_IDLE, STATE_START, STATE_READ, STATE_WRITE }; struct synquacer_i2c { struct completion completion; struct i2c_msg *msg; u32 msg_num; u32 msg_idx; u32 msg_ptr; int irq; struct device *dev; void __iomem *base; struct clk *pclk; u32 pclkrate; u32 speed_khz; u32 timeout_ms; enum i2c_state state; struct i2c_adapter adapter; }; static inline int is_lastmsg(struct synquacer_i2c *i2c) { return i2c->msg_idx >= (i2c->msg_num - 1); } static inline int is_msglast(struct synquacer_i2c *i2c) { return i2c->msg_ptr == (i2c->msg->len - 1); } static inline int is_msgend(struct synquacer_i2c *i2c) { return i2c->msg_ptr >= i2c->msg->len; } static inline unsigned long calc_timeout_ms(struct synquacer_i2c *i2c, struct i2c_msg *msgs, int num) { unsigned long bit_count = 0; int i; for (i = 0; i < num; i++, msgs++) bit_count += msgs->len; return DIV_ROUND_UP((bit_count * 9 + num * 10) * 3, 200) + 10; } static void synquacer_i2c_stop(struct synquacer_i2c *i2c, int ret) { /* * clear IRQ (INT=0, BER=0) * set Stop Condition (MSS=0) * Interrupt Disable */ writeb(0, i2c->base + SYNQUACER_I2C_REG_BCR); i2c->state = STATE_IDLE; i2c->msg_ptr = 0; i2c->msg = NULL; i2c->msg_idx++; i2c->msg_num = 0; if (ret) i2c->msg_idx = ret; complete(&i2c->completion); } static void synquacer_i2c_hw_init(struct synquacer_i2c *i2c) { unsigned char ccr_cs, csr_cs; u32 rt = i2c->pclkrate; /* Set own Address */ writeb(0, i2c->base + SYNQUACER_I2C_REG_ADR); /* Set PCLK frequency */ writeb(SYNQUACER_I2C_BUS_CLK_FR(i2c->pclkrate), i2c->base + SYNQUACER_I2C_REG_FSR); switch (i2c->speed_khz) { case SYNQUACER_I2C_SPEED_FM: if (i2c->pclkrate <= SYNQUACER_I2C_CLK_RATE_18M) { ccr_cs = SYNQUACER_I2C_CCR_CS_FAST_MAX_18M(rt); csr_cs = SYNQUACER_I2C_CSR_CS_FAST_MAX_18M(rt); } else { ccr_cs = SYNQUACER_I2C_CCR_CS_FAST_MIN_18M(rt); csr_cs = SYNQUACER_I2C_CSR_CS_FAST_MIN_18M(rt); } /* Set Clock and enable, Set fast mode */ writeb(ccr_cs | SYNQUACER_I2C_CCR_FM | SYNQUACER_I2C_CCR_EN, i2c->base + SYNQUACER_I2C_REG_CCR); writeb(csr_cs, i2c->base + SYNQUACER_I2C_REG_CSR); break; case SYNQUACER_I2C_SPEED_SM: if (i2c->pclkrate <= SYNQUACER_I2C_CLK_RATE_18M) { ccr_cs = SYNQUACER_I2C_CCR_CS_STD_MAX_18M(rt); csr_cs = SYNQUACER_I2C_CSR_CS_STD_MAX_18M(rt); } else { ccr_cs = SYNQUACER_I2C_CCR_CS_STD_MIN_18M(rt); csr_cs = SYNQUACER_I2C_CSR_CS_STD_MIN_18M(rt); } /* Set Clock and enable, Set standard mode */ writeb(ccr_cs | SYNQUACER_I2C_CCR_EN, i2c->base + SYNQUACER_I2C_REG_CCR); writeb(csr_cs, i2c->base + SYNQUACER_I2C_REG_CSR); break; default: WARN_ON(1); } /* clear IRQ (INT=0, BER=0), Interrupt Disable */ writeb(0, i2c->base + SYNQUACER_I2C_REG_BCR); writeb(0, i2c->base + SYNQUACER_I2C_REG_BC2R); } static void synquacer_i2c_hw_reset(struct synquacer_i2c *i2c) { /* Disable clock */ writeb(0, i2c->base + SYNQUACER_I2C_REG_CCR); writeb(0, i2c->base + SYNQUACER_I2C_REG_CSR); WAIT_PCLK(100, i2c->pclkrate); } static int synquacer_i2c_master_start(struct synquacer_i2c *i2c, struct i2c_msg *pmsg) { unsigned char bsr, bcr; writeb(i2c_8bit_addr_from_msg(pmsg), i2c->base + SYNQUACER_I2C_REG_DAR); dev_dbg(i2c->dev, "slave:0x%02x\n", pmsg->addr); /* Generate Start Condition */ bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR); bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR); dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr); if ((bsr & SYNQUACER_I2C_BSR_BB) && !(bcr & SYNQUACER_I2C_BCR_MSS)) { dev_dbg(i2c->dev, "bus is busy"); return -EBUSY; } if (bsr & SYNQUACER_I2C_BSR_BB) { /* Bus is busy */ dev_dbg(i2c->dev, "Continuous Start"); writeb(bcr | SYNQUACER_I2C_BCR_SCC, i2c->base + SYNQUACER_I2C_REG_BCR); } else { if (bcr & SYNQUACER_I2C_BCR_MSS) { dev_dbg(i2c->dev, "not in master mode"); return -EAGAIN; } dev_dbg(i2c->dev, "Start Condition"); /* Start Condition + Enable Interrupts */ writeb(bcr | SYNQUACER_I2C_BCR_MSS | SYNQUACER_I2C_BCR_INTE | SYNQUACER_I2C_BCR_BEIE, i2c->base + SYNQUACER_I2C_REG_BCR); } WAIT_PCLK(10, i2c->pclkrate); /* get BSR & BCR registers */ bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR); bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR); dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr); if ((bsr & SYNQUACER_I2C_BSR_AL) || !(bcr & SYNQUACER_I2C_BCR_MSS)) { dev_dbg(i2c->dev, "arbitration lost\n"); return -EAGAIN; } return 0; } static int synquacer_i2c_doxfer(struct synquacer_i2c *i2c, struct i2c_msg *msgs, int num) { unsigned char bsr; unsigned long timeout; int ret; synquacer_i2c_hw_init(i2c); bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR); if (bsr & SYNQUACER_I2C_BSR_BB) { dev_err(i2c->dev, "cannot get bus (bus busy)\n"); return -EBUSY; } reinit_completion(&i2c->completion); i2c->msg = msgs; i2c->msg_num = num; i2c->msg_ptr = 0; i2c->msg_idx = 0; i2c->state = STATE_START; ret = synquacer_i2c_master_start(i2c, i2c->msg); if (ret < 0) { dev_dbg(i2c->dev, "Address failed: (%d)\n", ret); return ret; } timeout = wait_for_completion_timeout(&i2c->completion, msecs_to_jiffies(i2c->timeout_ms)); if (timeout == 0) { dev_dbg(i2c->dev, "timeout\n"); return -EAGAIN; } ret = i2c->msg_idx; if (ret != num) { dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); return -EAGAIN; } /* wait 2 clock periods to ensure the stop has been through the bus */ udelay(DIV_ROUND_UP(2 * 1000, i2c->speed_khz)); return 0; } static irqreturn_t synquacer_i2c_isr(int irq, void *dev_id) { struct synquacer_i2c *i2c = dev_id; unsigned char byte; unsigned char bsr, bcr; int ret; bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR); bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR); dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr); if (bcr & SYNQUACER_I2C_BCR_BER) { dev_err(i2c->dev, "bus error\n"); synquacer_i2c_stop(i2c, -EAGAIN); goto out; } if ((bsr & SYNQUACER_I2C_BSR_AL) || !(bcr & SYNQUACER_I2C_BCR_MSS)) { dev_dbg(i2c->dev, "arbitration lost\n"); synquacer_i2c_stop(i2c, -EAGAIN); goto out; } switch (i2c->state) { case STATE_START: if (bsr & SYNQUACER_I2C_BSR_LRB) { dev_dbg(i2c->dev, "ack was not received\n"); synquacer_i2c_stop(i2c, -EAGAIN); goto out; } if (i2c->msg->flags & I2C_M_RD) i2c->state = STATE_READ; else i2c->state = STATE_WRITE; if (is_lastmsg(i2c) && i2c->msg->len == 0) { synquacer_i2c_stop(i2c, 0); goto out; } if (i2c->state == STATE_READ) goto prepare_read; /* fall through */ case STATE_WRITE: if (bsr & SYNQUACER_I2C_BSR_LRB) { dev_dbg(i2c->dev, "WRITE: No Ack\n"); synquacer_i2c_stop(i2c, -EAGAIN); goto out; } if (!is_msgend(i2c)) { writeb(i2c->msg->buf[i2c->msg_ptr++], i2c->base + SYNQUACER_I2C_REG_DAR); /* clear IRQ, and continue */ writeb(SYNQUACER_I2C_BCR_BEIE | SYNQUACER_I2C_BCR_MSS | SYNQUACER_I2C_BCR_INTE, i2c->base + SYNQUACER_I2C_REG_BCR); break; } if (is_lastmsg(i2c)) { synquacer_i2c_stop(i2c, 0); break; } dev_dbg(i2c->dev, "WRITE: Next Message\n"); i2c->msg_ptr = 0; i2c->msg_idx++; i2c->msg++; /* send the new start */ ret = synquacer_i2c_master_start(i2c, i2c->msg); if (ret < 0) { dev_dbg(i2c->dev, "restart error (%d)\n", ret); synquacer_i2c_stop(i2c, -EAGAIN); break; } i2c->state = STATE_START; break; case STATE_READ: byte = readb(i2c->base + SYNQUACER_I2C_REG_DAR); if (!(bsr & SYNQUACER_I2C_BSR_FBT)) /* data */ i2c->msg->buf[i2c->msg_ptr++] = byte; else /* address */ dev_dbg(i2c->dev, "address:0x%02x. ignore it.\n", byte); prepare_read: if (is_msglast(i2c)) { writeb(SYNQUACER_I2C_BCR_MSS | SYNQUACER_I2C_BCR_BEIE | SYNQUACER_I2C_BCR_INTE, i2c->base + SYNQUACER_I2C_REG_BCR); break; } if (!is_msgend(i2c)) { writeb(SYNQUACER_I2C_BCR_MSS | SYNQUACER_I2C_BCR_BEIE | SYNQUACER_I2C_BCR_INTE | SYNQUACER_I2C_BCR_ACK, i2c->base + SYNQUACER_I2C_REG_BCR); break; } if (is_lastmsg(i2c)) { /* last message, send stop and complete */ dev_dbg(i2c->dev, "READ: Send Stop\n"); synquacer_i2c_stop(i2c, 0); break; } dev_dbg(i2c->dev, "READ: Next Transfer\n"); i2c->msg_ptr = 0; i2c->msg_idx++; i2c->msg++; ret = synquacer_i2c_master_start(i2c, i2c->msg); if (ret < 0) { dev_dbg(i2c->dev, "restart error (%d)\n", ret); synquacer_i2c_stop(i2c, -EAGAIN); } else { i2c->state = STATE_START; } break; default: dev_err(i2c->dev, "called in err STATE (%d)\n", i2c->state); break; } out: WAIT_PCLK(10, i2c->pclkrate); return IRQ_HANDLED; } static int synquacer_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct synquacer_i2c *i2c; int retry; int ret; i2c = i2c_get_adapdata(adap); i2c->timeout_ms = calc_timeout_ms(i2c, msgs, num); dev_dbg(i2c->dev, "calculated timeout %d ms\n", i2c->timeout_ms); for (retry = 0; retry <= adap->retries; retry++) { ret = synquacer_i2c_doxfer(i2c, msgs, num); if (ret != -EAGAIN) return ret; dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); synquacer_i2c_hw_reset(i2c); } return -EIO; } static u32 synquacer_i2c_functionality(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static const struct i2c_algorithm synquacer_i2c_algo = { .master_xfer = synquacer_i2c_xfer, .functionality = synquacer_i2c_functionality, }; static struct i2c_adapter synquacer_i2c_ops = { .owner = THIS_MODULE, .name = "synquacer_i2c-adapter", .algo = &synquacer_i2c_algo, .retries = 5, }; static int synquacer_i2c_probe(struct platform_device *pdev) { struct synquacer_i2c *i2c; struct resource *r; u32 bus_speed; int ret; i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; bus_speed = i2c_acpi_find_bus_speed(&pdev->dev); if (!bus_speed) device_property_read_u32(&pdev->dev, "clock-frequency", &bus_speed); device_property_read_u32(&pdev->dev, "socionext,pclk-rate", &i2c->pclkrate); i2c->pclk = devm_clk_get(&pdev->dev, "pclk"); if (IS_ERR(i2c->pclk) && PTR_ERR(i2c->pclk) == -EPROBE_DEFER) return -EPROBE_DEFER; if (!IS_ERR_OR_NULL(i2c->pclk)) { dev_dbg(&pdev->dev, "clock source %p\n", i2c->pclk); ret = clk_prepare_enable(i2c->pclk); if (ret) { dev_err(&pdev->dev, "failed to enable clock (%d)\n", ret); return ret; } i2c->pclkrate = clk_get_rate(i2c->pclk); } if (i2c->pclkrate < SYNQUACER_I2C_MIN_CLK_RATE || i2c->pclkrate > SYNQUACER_I2C_MAX_CLK_RATE) { dev_err(&pdev->dev, "PCLK missing or out of range (%d)\n", i2c->pclkrate); return -EINVAL; } r = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c->base = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(i2c->base)) return PTR_ERR(i2c->base); i2c->irq = platform_get_irq(pdev, 0); if (i2c->irq < 0) { dev_err(&pdev->dev, "no IRQ resource found\n"); return -ENODEV; } ret = devm_request_irq(&pdev->dev, i2c->irq, synquacer_i2c_isr, 0, dev_name(&pdev->dev), i2c); if (ret < 0) { dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); return ret; } i2c->state = STATE_IDLE; i2c->dev = &pdev->dev; i2c->adapter = synquacer_i2c_ops; i2c_set_adapdata(&i2c->adapter, i2c); i2c->adapter.dev.parent = &pdev->dev; i2c->adapter.dev.of_node = pdev->dev.of_node; ACPI_COMPANION_SET(&i2c->adapter.dev, ACPI_COMPANION(&pdev->dev)); i2c->adapter.nr = pdev->id; init_completion(&i2c->completion); if (bus_speed < 400000) i2c->speed_khz = SYNQUACER_I2C_SPEED_SM; else i2c->speed_khz = SYNQUACER_I2C_SPEED_FM; synquacer_i2c_hw_init(i2c); ret = i2c_add_numbered_adapter(&i2c->adapter); if (ret) { dev_err(&pdev->dev, "failed to add bus to i2c core\n"); return ret; } platform_set_drvdata(pdev, i2c); dev_info(&pdev->dev, "%s: synquacer_i2c adapter\n", dev_name(&i2c->adapter.dev)); return 0; } static int synquacer_i2c_remove(struct platform_device *pdev) { struct synquacer_i2c *i2c = platform_get_drvdata(pdev); i2c_del_adapter(&i2c->adapter); if (!IS_ERR(i2c->pclk)) clk_disable_unprepare(i2c->pclk); return 0; }; static const struct of_device_id synquacer_i2c_dt_ids[] = { { .compatible = "socionext,synquacer-i2c" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, synquacer_i2c_dt_ids); #ifdef CONFIG_ACPI static const struct acpi_device_id synquacer_i2c_acpi_ids[] = { { "SCX0003" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(acpi, synquacer_i2c_acpi_ids); #endif static struct platform_driver synquacer_i2c_driver = { .probe = synquacer_i2c_probe, .remove = synquacer_i2c_remove, .driver = { .name = "synquacer_i2c", .of_match_table = of_match_ptr(synquacer_i2c_dt_ids), .acpi_match_table = ACPI_PTR(synquacer_i2c_acpi_ids), }, }; module_platform_driver(synquacer_i2c_driver); MODULE_AUTHOR("Fujitsu Semiconductor Ltd"); MODULE_DESCRIPTION("Socionext SynQuacer I2C Driver"); MODULE_LICENSE("GPL v2");