diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-octeon.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-octeon.c | 1011 |
1 files changed, 833 insertions, 178 deletions
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c index 46fb6c429..30ae35146 100644 --- a/drivers/i2c/busses/i2c-octeon.c +++ b/drivers/i2c/busses/i2c-octeon.c @@ -11,6 +11,7 @@ * warranty of any kind, whether express or implied. */ +#include <linux/atomic.h> #include <linux/platform_device.h> #include <linux/interrupt.h> #include <linux/kernel.h> @@ -29,13 +30,23 @@ /* Register offsets */ #define SW_TWSI 0x00 #define TWSI_INT 0x10 +#define SW_TWSI_EXT 0x18 /* Controller command patterns */ #define SW_TWSI_V BIT_ULL(63) /* Valid bit */ +#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */ #define SW_TWSI_R BIT_ULL(56) /* Result or read bit */ +#define SW_TWSI_SOVR BIT_ULL(55) /* Size override */ +#define SW_TWSI_SIZE_SHIFT 52 +#define SW_TWSI_ADDR_SHIFT 40 +#define SW_TWSI_IA_SHIFT 32 /* Internal address */ /* Controller opcode word (bits 60:57) */ #define SW_TWSI_OP_SHIFT 57 +#define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT) +#define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT) +#define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT) +#define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT) #define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT) #define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */ @@ -48,46 +59,93 @@ #define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT) /* Controller command and status bits */ -#define TWSI_CTL_CE 0x80 +#define TWSI_CTL_CE 0x80 /* High level controller enable */ #define TWSI_CTL_ENAB 0x40 /* Bus enable */ #define TWSI_CTL_STA 0x20 /* Master-mode start, HW clears when done */ #define TWSI_CTL_STP 0x10 /* Master-mode stop, HW clears when done */ #define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */ #define TWSI_CTL_AAK 0x04 /* Assert ACK */ -/* Some status values */ +/* Status values */ +#define STAT_ERROR 0x00 #define STAT_START 0x08 -#define STAT_RSTART 0x10 +#define STAT_REP_START 0x10 #define STAT_TXADDR_ACK 0x18 +#define STAT_TXADDR_NAK 0x20 #define STAT_TXDATA_ACK 0x28 +#define STAT_TXDATA_NAK 0x30 +#define STAT_LOST_ARB_38 0x38 #define STAT_RXADDR_ACK 0x40 +#define STAT_RXADDR_NAK 0x48 #define STAT_RXDATA_ACK 0x50 +#define STAT_RXDATA_NAK 0x58 +#define STAT_SLAVE_60 0x60 +#define STAT_LOST_ARB_68 0x68 +#define STAT_SLAVE_70 0x70 +#define STAT_LOST_ARB_78 0x78 +#define STAT_SLAVE_80 0x80 +#define STAT_SLAVE_88 0x88 +#define STAT_GENDATA_ACK 0x90 +#define STAT_GENDATA_NAK 0x98 +#define STAT_SLAVE_A0 0xA0 +#define STAT_SLAVE_A8 0xA8 +#define STAT_LOST_ARB_B0 0xB0 +#define STAT_SLAVE_LOST 0xB8 +#define STAT_SLAVE_NAK 0xC0 +#define STAT_SLAVE_ACK 0xC8 +#define STAT_AD2W_ACK 0xD0 +#define STAT_AD2W_NAK 0xD8 #define STAT_IDLE 0xF8 /* TWSI_INT values */ +#define TWSI_INT_ST_INT BIT_ULL(0) +#define TWSI_INT_TS_INT BIT_ULL(1) +#define TWSI_INT_CORE_INT BIT_ULL(2) +#define TWSI_INT_ST_EN BIT_ULL(4) +#define TWSI_INT_TS_EN BIT_ULL(5) #define TWSI_INT_CORE_EN BIT_ULL(6) #define TWSI_INT_SDA_OVR BIT_ULL(8) #define TWSI_INT_SCL_OVR BIT_ULL(9) +#define TWSI_INT_SDA BIT_ULL(10) +#define TWSI_INT_SCL BIT_ULL(11) + +#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */ struct octeon_i2c { wait_queue_head_t queue; struct i2c_adapter adap; int irq; + int hlc_irq; /* For cn7890 only */ u32 twsi_freq; int sys_freq; void __iomem *twsi_base; struct device *dev; + bool hlc_enabled; + bool broken_irq_mode; + bool broken_irq_check; + void (*int_enable)(struct octeon_i2c *); + void (*int_disable)(struct octeon_i2c *); + void (*hlc_int_enable)(struct octeon_i2c *); + void (*hlc_int_disable)(struct octeon_i2c *); + atomic_t int_enable_cnt; + atomic_t hlc_int_enable_cnt; }; +static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr) +{ + __raw_writeq(val, addr); + __raw_readq(addr); /* wait for write to land */ +} + /** - * octeon_i2c_write_sw - write an I2C core register + * octeon_i2c_reg_write - write an I2C core register * @i2c: The struct octeon_i2c * @eop_reg: Register selector * @data: Value to be written * * The I2C core registers are accessed indirectly via the SW_TWSI CSR. */ -static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data) +static void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data) { u64 tmp; @@ -97,8 +155,13 @@ static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data) } while ((tmp & SW_TWSI_V) != 0); } +#define octeon_i2c_ctl_write(i2c, val) \ + octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val) +#define octeon_i2c_data_write(i2c, val) \ + octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val) + /** - * octeon_i2c_read_sw - read lower bits of an I2C core register + * octeon_i2c_reg_read - read lower bits of an I2C core register * @i2c: The struct octeon_i2c * @eop_reg: Register selector * @@ -106,7 +169,7 @@ static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data) * * The I2C core registers are accessed indirectly via the SW_TWSI CSR. */ -static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg) +static u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg) { u64 tmp; @@ -118,6 +181,24 @@ static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg) return tmp & 0xFF; } +#define octeon_i2c_ctl_read(i2c) \ + octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL) +#define octeon_i2c_data_read(i2c) \ + octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA) +#define octeon_i2c_stat_read(i2c) \ + octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT) + +/** + * octeon_i2c_read_int - read the TWSI_INT register + * @i2c: The struct octeon_i2c + * + * Returns the value of the register. + */ +static u64 octeon_i2c_read_int(struct octeon_i2c *i2c) +{ + return __raw_readq(i2c->twsi_base + TWSI_INT); +} + /** * octeon_i2c_write_int - write the TWSI_INT register * @i2c: The struct octeon_i2c @@ -125,8 +206,7 @@ static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg) */ static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data) { - __raw_writeq(data, i2c->twsi_base + TWSI_INT); - __raw_readq(i2c->twsi_base + TWSI_INT); + octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT); } /** @@ -149,30 +229,96 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c) } /** - * octeon_i2c_unblock - unblock the bus + * octeon_i2c_int_enable78 - enable the CORE interrupt + * @i2c: The struct octeon_i2c + * + * The interrupt will be asserted when there is non-STAT_IDLE state in the + * SW_TWSI_EOP_TWSI_STAT register. + */ +static void octeon_i2c_int_enable78(struct octeon_i2c *i2c) +{ + atomic_inc_return(&i2c->int_enable_cnt); + enable_irq(i2c->irq); +} + +static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq) +{ + int count; + + /* + * The interrupt can be disabled in two places, but we only + * want to make the disable_irq_nosync() call once, so keep + * track with the atomic variable. + */ + count = atomic_dec_if_positive(cnt); + if (count >= 0) + disable_irq_nosync(irq); +} + +/* disable the CORE interrupt */ +static void octeon_i2c_int_disable78(struct octeon_i2c *i2c) +{ + __octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq); +} + +/** + * octeon_i2c_hlc_int_enable78 - enable the ST interrupt * @i2c: The struct octeon_i2c * - * If there was a reset while a device was driving 0 to bus, bus is blocked. - * We toggle it free manually by some clock cycles and send a stop. + * The interrupt will be asserted when there is non-STAT_IDLE state in + * the SW_TWSI_EOP_TWSI_STAT register. + */ +static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c) +{ + atomic_inc_return(&i2c->hlc_int_enable_cnt); + enable_irq(i2c->hlc_irq); +} + +/* disable the ST interrupt */ +static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c) +{ + __octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq); +} + +/* + * Cleanup low-level state & enable high-level controller. */ -static void octeon_i2c_unblock(struct octeon_i2c *i2c) +static void octeon_i2c_hlc_enable(struct octeon_i2c *i2c) { - int i; + int try = 0; + u64 val; + + if (i2c->hlc_enabled) + return; + i2c->hlc_enabled = true; + + while (1) { + val = octeon_i2c_ctl_read(i2c); + if (!(val & (TWSI_CTL_STA | TWSI_CTL_STP))) + break; - dev_dbg(i2c->dev, "%s\n", __func__); + /* clear IFLG event */ + if (val & TWSI_CTL_IFLG) + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB); + + if (try++ > 100) { + pr_err("%s: giving up\n", __func__); + break; + } - for (i = 0; i < 9; i++) { - octeon_i2c_write_int(i2c, 0); - udelay(5); - octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR); - udelay(5); + /* spin until any start/stop has finished */ + udelay(10); } - /* hand-crank a STOP */ - octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR); - udelay(5); - octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR); - udelay(5); - octeon_i2c_write_int(i2c, 0); + octeon_i2c_ctl_write(i2c, TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB); +} + +static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c) +{ + if (!i2c->hlc_enabled) + return; + + i2c->hlc_enabled = false; + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB); } /* interrupt service routine */ @@ -180,16 +326,44 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id) { struct octeon_i2c *i2c = dev_id; - octeon_i2c_int_disable(i2c); + i2c->int_disable(i2c); + wake_up(&i2c->queue); + + return IRQ_HANDLED; +} + +/* HLC interrupt service routine */ +static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id) +{ + struct octeon_i2c *i2c = dev_id; + + i2c->hlc_int_disable(i2c); wake_up(&i2c->queue); return IRQ_HANDLED; } +static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c) +{ + return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG); +} -static int octeon_i2c_test_iflg(struct octeon_i2c *i2c) +static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first) { - return (octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_CTL) & TWSI_CTL_IFLG) != 0; + if (octeon_i2c_test_iflg(i2c)) + return true; + + if (*first) { + *first = false; + return false; + } + + /* + * IRQ has signaled an event but IFLG hasn't changed. + * Sleep and retry once. + */ + usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT); + return octeon_i2c_test_iflg(i2c); } /** @@ -201,64 +375,493 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c) static int octeon_i2c_wait(struct octeon_i2c *i2c) { long time_left; + bool first = 1; - octeon_i2c_int_enable(i2c); - time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c), + /* + * Some chip revisions don't assert the irq in the interrupt + * controller. So we must poll for the IFLG change. + */ + if (i2c->broken_irq_mode) { + u64 end = get_jiffies_64() + i2c->adap.timeout; + + while (!octeon_i2c_test_iflg(i2c) && + time_before64(get_jiffies_64(), end)) + usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT); + + return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT; + } + + i2c->int_enable(i2c); + time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first), i2c->adap.timeout); - octeon_i2c_int_disable(i2c); - if (!time_left) { - dev_dbg(i2c->dev, "%s: timeout\n", __func__); - return -ETIMEDOUT; + i2c->int_disable(i2c); + + if (i2c->broken_irq_check && !time_left && + octeon_i2c_test_iflg(i2c)) { + dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n"); + i2c->broken_irq_mode = true; + return 0; } + if (!time_left) + return -ETIMEDOUT; + return 0; } +static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read) +{ + u8 stat = octeon_i2c_stat_read(i2c); + + switch (stat) { + /* Everything is fine */ + case STAT_IDLE: + case STAT_AD2W_ACK: + case STAT_RXADDR_ACK: + case STAT_TXADDR_ACK: + case STAT_TXDATA_ACK: + return 0; + + /* ACK allowed on pre-terminal bytes only */ + case STAT_RXDATA_ACK: + if (!final_read) + return 0; + return -EIO; + + /* NAK allowed on terminal byte only */ + case STAT_RXDATA_NAK: + if (final_read) + return 0; + return -EIO; + + /* Arbitration lost */ + case STAT_LOST_ARB_38: + case STAT_LOST_ARB_68: + case STAT_LOST_ARB_78: + case STAT_LOST_ARB_B0: + return -EAGAIN; + + /* Being addressed as slave, should back off & listen */ + case STAT_SLAVE_60: + case STAT_SLAVE_70: + case STAT_GENDATA_ACK: + case STAT_GENDATA_NAK: + return -EOPNOTSUPP; + + /* Core busy as slave */ + case STAT_SLAVE_80: + case STAT_SLAVE_88: + case STAT_SLAVE_A0: + case STAT_SLAVE_A8: + case STAT_SLAVE_LOST: + case STAT_SLAVE_NAK: + case STAT_SLAVE_ACK: + return -EOPNOTSUPP; + + case STAT_TXDATA_NAK: + return -EIO; + case STAT_TXADDR_NAK: + case STAT_RXADDR_NAK: + case STAT_AD2W_NAK: + return -ENXIO; + default: + dev_err(i2c->dev, "unhandled state: %d\n", stat); + return -EIO; + } +} + +static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c) +{ + return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0; +} + +static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first) +{ + /* check if valid bit is cleared */ + if (octeon_i2c_hlc_test_valid(i2c)) + return true; + + if (*first) { + *first = false; + return false; + } + + /* + * IRQ has signaled an event but valid bit isn't cleared. + * Sleep and retry once. + */ + usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT); + return octeon_i2c_hlc_test_valid(i2c); +} + +static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c) +{ + octeon_i2c_write_int(i2c, TWSI_INT_ST_EN); +} + +static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c) +{ + /* clear ST/TS events, listen for neither */ + octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT); +} + /** - * octeon_i2c_start - send START to the bus + * octeon_i2c_hlc_wait - wait for an HLC operation to complete * @i2c: The struct octeon_i2c * - * Returns 0 on success, otherwise a negative errno. + * Returns 0 on success, otherwise -ETIMEDOUT. */ -static int octeon_i2c_start(struct octeon_i2c *i2c) +static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c) { - int result; - u8 data; + bool first = 1; + int time_left; - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, - TWSI_CTL_ENAB | TWSI_CTL_STA); + /* + * Some cn38xx boards don't assert the irq in the interrupt + * controller. So we must poll for the valid bit change. + */ + if (i2c->broken_irq_mode) { + u64 end = get_jiffies_64() + i2c->adap.timeout; - result = octeon_i2c_wait(i2c); - if (result) { - if (octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT) == STAT_IDLE) { + while (!octeon_i2c_hlc_test_valid(i2c) && + time_before64(get_jiffies_64(), end)) + usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT); + + return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT; + } + + i2c->hlc_int_enable(i2c); + time_left = wait_event_timeout(i2c->queue, + octeon_i2c_hlc_test_ready(i2c, &first), + i2c->adap.timeout); + i2c->hlc_int_disable(i2c); + if (!time_left) + octeon_i2c_hlc_int_clear(i2c); + + if (i2c->broken_irq_check && !time_left && + octeon_i2c_hlc_test_valid(i2c)) { + dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n"); + i2c->broken_irq_mode = true; + return 0; + } + + if (!time_left) + return -ETIMEDOUT; + return 0; +} + +/* high-level-controller pure read of up to 8 bytes */ +static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs) +{ + int i, j, ret = 0; + u64 cmd; + + octeon_i2c_hlc_enable(i2c); + octeon_i2c_hlc_int_clear(i2c); + + cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR; + /* SIZE */ + cmd |= (u64)(msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT; + /* A */ + cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT; + + if (msgs[0].flags & I2C_M_TEN) + cmd |= SW_TWSI_OP_10; + else + cmd |= SW_TWSI_OP_7; + + octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI); + ret = octeon_i2c_hlc_wait(i2c); + if (ret) + goto err; + + cmd = __raw_readq(i2c->twsi_base + SW_TWSI); + if ((cmd & SW_TWSI_R) == 0) + return -EAGAIN; + + for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--) + msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff; + + if (msgs[0].len > 4) { + cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT); + for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--) + msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff; + } + +err: + return ret; +} + +/* high-level-controller pure write of up to 8 bytes */ +static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs) +{ + int i, j, ret = 0; + u64 cmd; + + octeon_i2c_hlc_enable(i2c); + octeon_i2c_hlc_int_clear(i2c); + + cmd = SW_TWSI_V | SW_TWSI_SOVR; + /* SIZE */ + cmd |= (u64)(msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT; + /* A */ + cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT; + + if (msgs[0].flags & I2C_M_TEN) + cmd |= SW_TWSI_OP_10; + else + cmd |= SW_TWSI_OP_7; + + for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--) + cmd |= (u64)msgs[0].buf[j] << (8 * i); + + if (msgs[0].len > 4) { + u64 ext = 0; + + for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--) + ext |= (u64)msgs[0].buf[j] << (8 * i); + octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT); + } + + octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI); + ret = octeon_i2c_hlc_wait(i2c); + if (ret) + goto err; + + cmd = __raw_readq(i2c->twsi_base + SW_TWSI); + if ((cmd & SW_TWSI_R) == 0) + return -EAGAIN; + + ret = octeon_i2c_check_status(i2c, false); + +err: + return ret; +} + +/* high-level-controller composite write+read, msg0=addr, msg1=data */ +static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs) +{ + int i, j, ret = 0; + u64 cmd; + + octeon_i2c_hlc_enable(i2c); + + cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR; + /* SIZE */ + cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT; + /* A */ + cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT; + + if (msgs[0].flags & I2C_M_TEN) + cmd |= SW_TWSI_OP_10_IA; + else + cmd |= SW_TWSI_OP_7_IA; + + if (msgs[0].len == 2) { + u64 ext = 0; + + cmd |= SW_TWSI_EIA; + ext = (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT; + cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT; + octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT); + } else { + cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT; + } + + octeon_i2c_hlc_int_clear(i2c); + octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI); + + ret = octeon_i2c_hlc_wait(i2c); + if (ret) + goto err; + + cmd = __raw_readq(i2c->twsi_base + SW_TWSI); + if ((cmd & SW_TWSI_R) == 0) + return -EAGAIN; + + for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--) + msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff; + + if (msgs[1].len > 4) { + cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT); + for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--) + msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff; + } + +err: + return ret; +} + +/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */ +static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs) +{ + bool set_ext = false; + int i, j, ret = 0; + u64 cmd, ext = 0; + + octeon_i2c_hlc_enable(i2c); + + cmd = SW_TWSI_V | SW_TWSI_SOVR; + /* SIZE */ + cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT; + /* A */ + cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT; + + if (msgs[0].flags & I2C_M_TEN) + cmd |= SW_TWSI_OP_10_IA; + else + cmd |= SW_TWSI_OP_7_IA; + + if (msgs[0].len == 2) { + cmd |= SW_TWSI_EIA; + ext |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT; + set_ext = true; + cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT; + } else { + cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT; + } + + for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--) + cmd |= (u64)msgs[1].buf[j] << (8 * i); + + if (msgs[1].len > 4) { + for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--) + ext |= (u64)msgs[1].buf[j] << (8 * i); + set_ext = true; + } + if (set_ext) + octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT); + + octeon_i2c_hlc_int_clear(i2c); + octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI); + + ret = octeon_i2c_hlc_wait(i2c); + if (ret) + goto err; + + cmd = __raw_readq(i2c->twsi_base + SW_TWSI); + if ((cmd & SW_TWSI_R) == 0) + return -EAGAIN; + + ret = octeon_i2c_check_status(i2c, false); + +err: + return ret; +} + +/* calculate and set clock divisors */ +static void octeon_i2c_set_clock(struct octeon_i2c *i2c) +{ + int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff; + int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000; + + for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) { + /* + * An mdiv value of less than 2 seems to not work well + * with ds1337 RTCs, so we constrain it to larger values. + */ + for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) { /* - * Controller refused to send start flag May - * be a client is holding SDA low - let's try - * to free it. + * For given ndiv and mdiv values check the + * two closest thp values. */ - octeon_i2c_unblock(i2c); - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, - TWSI_CTL_ENAB | TWSI_CTL_STA); - result = octeon_i2c_wait(i2c); + tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10; + tclk *= (1 << ndiv_idx); + thp_base = (i2c->sys_freq / (tclk * 2)) - 1; + + for (inc = 0; inc <= 1; inc++) { + thp_idx = thp_base + inc; + if (thp_idx < 5 || thp_idx > 0xff) + continue; + + foscl = i2c->sys_freq / (2 * (thp_idx + 1)); + foscl = foscl / (1 << ndiv_idx); + foscl = foscl / (mdiv_idx + 1) / 10; + diff = abs(foscl - i2c->twsi_freq); + if (diff < delta_hz) { + delta_hz = diff; + thp = thp_idx; + mdiv = mdiv_idx; + ndiv = ndiv_idx; + } + } } - if (result) - return result; + } + octeon_i2c_reg_write(i2c, SW_TWSI_OP_TWSI_CLK, thp); + octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv); +} + +static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c) +{ + u8 status = 0; + int tries; + + /* reset controller */ + octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0); + + for (tries = 10; tries && status != STAT_IDLE; tries--) { + udelay(1); + status = octeon_i2c_stat_read(i2c); + if (status == STAT_IDLE) + break; } - data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); - if ((data != STAT_START) && (data != STAT_RSTART)) { - dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data); + if (status != STAT_IDLE) { + dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", + __func__, status); return -EIO; } + /* toggle twice to force both teardowns */ + octeon_i2c_hlc_enable(i2c); + octeon_i2c_hlc_disable(i2c); return 0; } +static int octeon_i2c_recovery(struct octeon_i2c *i2c) +{ + int ret; + + ret = i2c_recover_bus(&i2c->adap); + if (ret) + /* recover failed, try hardware re-init */ + ret = octeon_i2c_init_lowlevel(i2c); + return ret; +} + +/** + * octeon_i2c_start - send START to the bus + * @i2c: The struct octeon_i2c + * + * Returns 0 on success, otherwise a negative errno. + */ +static int octeon_i2c_start(struct octeon_i2c *i2c) +{ + int ret; + u8 stat; + + octeon_i2c_hlc_disable(i2c); + + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA); + ret = octeon_i2c_wait(i2c); + if (ret) + goto error; + + stat = octeon_i2c_stat_read(i2c); + if (stat == STAT_START || stat == STAT_REP_START) + /* START successful, bail out */ + return 0; + +error: + /* START failed, try to recover */ + ret = octeon_i2c_recovery(i2c); + return (ret) ? ret : -EAGAIN; +} + /* send STOP to the bus */ static void octeon_i2c_stop(struct octeon_i2c *i2c) { - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, - TWSI_CTL_ENAB | TWSI_CTL_STP); + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STP); } /** @@ -276,31 +879,21 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target, const u8 *data, int length) { int i, result; - u8 tmp; - - result = octeon_i2c_start(i2c); - if (result) - return result; - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1); - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); + octeon_i2c_data_write(i2c, target << 1); + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB); result = octeon_i2c_wait(i2c); if (result) return result; for (i = 0; i < length; i++) { - tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); - - if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) { - dev_err(i2c->dev, - "%s: bad status before write (0x%x)\n", - __func__, tmp); - return -EIO; - } + result = octeon_i2c_check_status(i2c, false); + if (result) + return result; - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]); - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); + octeon_i2c_data_write(i2c, data[i]); + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB); result = octeon_i2c_wait(i2c); if (result) @@ -326,53 +919,52 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target, u8 *data, u16 *rlength, bool recv_len) { int i, result, length = *rlength; - u8 tmp; + bool final_read = false; - if (length < 1) - return -EINVAL; + octeon_i2c_data_write(i2c, (target << 1) | 1); + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB); - result = octeon_i2c_start(i2c); + result = octeon_i2c_wait(i2c); if (result) return result; - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1); - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); - - result = octeon_i2c_wait(i2c); + /* address OK ? */ + result = octeon_i2c_check_status(i2c, false); if (result) return result; for (i = 0; i < length; i++) { - tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); - - if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) { - dev_err(i2c->dev, - "%s: bad status before read (0x%x)\n", - __func__, tmp); - return -EIO; - } + /* + * For the last byte to receive TWSI_CTL_AAK must not be set. + * + * A special case is I2C_M_RECV_LEN where we don't know the + * additional length yet. If recv_len is set we assume we're + * not reading the final byte and therefore need to set + * TWSI_CTL_AAK. + */ + if ((i + 1 == length) && !(recv_len && i == 0)) + final_read = true; - if (i + 1 < length) - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, - TWSI_CTL_ENAB | TWSI_CTL_AAK); + /* clear iflg to allow next event */ + if (final_read) + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB); else - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, - TWSI_CTL_ENAB); + octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK); result = octeon_i2c_wait(i2c); if (result) return result; - data[i] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA); + data[i] = octeon_i2c_data_read(i2c); if (recv_len && i == 0) { - if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) { - dev_err(i2c->dev, - "%s: read len > I2C_SMBUS_BLOCK_MAX %d\n", - __func__, data[i]); + if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) return -EPROTO; - } length += data[i]; } + + result = octeon_i2c_check_status(i2c, final_read); + if (result) + return result; } *rlength = length; return 0; @@ -392,13 +984,41 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, struct octeon_i2c *i2c = i2c_get_adapdata(adap); int i, ret = 0; + if (num == 1) { + if (msgs[0].len > 0 && msgs[0].len <= 8) { + if (msgs[0].flags & I2C_M_RD) + ret = octeon_i2c_hlc_read(i2c, msgs); + else + ret = octeon_i2c_hlc_write(i2c, msgs); + goto out; + } + } else if (num == 2) { + if ((msgs[0].flags & I2C_M_RD) == 0 && + (msgs[1].flags & I2C_M_RECV_LEN) == 0 && + msgs[0].len > 0 && msgs[0].len <= 2 && + msgs[1].len > 0 && msgs[1].len <= 8 && + msgs[0].addr == msgs[1].addr) { + if (msgs[1].flags & I2C_M_RD) + ret = octeon_i2c_hlc_comp_read(i2c, msgs); + else + ret = octeon_i2c_hlc_comp_write(i2c, msgs); + goto out; + } + } + for (i = 0; ret == 0 && i < num; i++) { struct i2c_msg *pmsg = &msgs[i]; - dev_dbg(i2c->dev, - "Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n", - pmsg->flags & I2C_M_RD ? "read" : "write", - pmsg->len, pmsg->addr, i + 1, num); + /* zero-length messages are not supported */ + if (!pmsg->len) { + ret = -EOPNOTSUPP; + break; + } + + ret = octeon_i2c_start(i2c); + if (ret) + return ret; + if (pmsg->flags & I2C_M_RD) ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf, &pmsg->len, pmsg->flags & I2C_M_RECV_LEN); @@ -407,102 +1027,105 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, pmsg->len); } octeon_i2c_stop(i2c); - +out: return (ret != 0) ? ret : num; } -static u32 octeon_i2c_functionality(struct i2c_adapter *adap) +static int octeon_i2c_get_scl(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | - I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL; + struct octeon_i2c *i2c = i2c_get_adapdata(adap); + u64 state; + + state = octeon_i2c_read_int(i2c); + return state & TWSI_INT_SCL; } -static const struct i2c_algorithm octeon_i2c_algo = { - .master_xfer = octeon_i2c_xfer, - .functionality = octeon_i2c_functionality, -}; +static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct octeon_i2c *i2c = i2c_get_adapdata(adap); -static struct i2c_adapter octeon_i2c_ops = { - .owner = THIS_MODULE, - .name = "OCTEON adapter", - .algo = &octeon_i2c_algo, - .timeout = HZ / 50, -}; + octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR); +} -/* calculate and set clock divisors */ -static void octeon_i2c_set_clock(struct octeon_i2c *i2c) +static int octeon_i2c_get_sda(struct i2c_adapter *adap) { - int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff; - int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000; + struct octeon_i2c *i2c = i2c_get_adapdata(adap); + u64 state; - for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) { - /* - * An mdiv value of less than 2 seems to not work well - * with ds1337 RTCs, so we constrain it to larger values. - */ - for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) { - /* - * For given ndiv and mdiv values check the - * two closest thp values. - */ - tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10; - tclk *= (1 << ndiv_idx); - thp_base = (i2c->sys_freq / (tclk * 2)) - 1; + state = octeon_i2c_read_int(i2c); + return state & TWSI_INT_SDA; +} - for (inc = 0; inc <= 1; inc++) { - thp_idx = thp_base + inc; - if (thp_idx < 5 || thp_idx > 0xff) - continue; +static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct octeon_i2c *i2c = i2c_get_adapdata(adap); - foscl = i2c->sys_freq / (2 * (thp_idx + 1)); - foscl = foscl / (1 << ndiv_idx); - foscl = foscl / (mdiv_idx + 1) / 10; - diff = abs(foscl - i2c->twsi_freq); - if (diff < delta_hz) { - delta_hz = diff; - thp = thp_idx; - mdiv = mdiv_idx; - ndiv = ndiv_idx; - } - } - } - } - octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp); - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv); + /* + * The stop resets the state machine, does not _transmit_ STOP unless + * engine was active. + */ + octeon_i2c_stop(i2c); + + octeon_i2c_hlc_disable(i2c); + octeon_i2c_write_int(i2c, 0); } -static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c) +static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap) { - u8 status; - int tries; + struct octeon_i2c *i2c = i2c_get_adapdata(adap); - /* disable high level controller, enable bus access */ - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB); + octeon_i2c_write_int(i2c, 0); +} - /* reset controller */ - octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0); +static struct i2c_bus_recovery_info octeon_i2c_recovery_info = { + .recover_bus = i2c_generic_scl_recovery, + .get_scl = octeon_i2c_get_scl, + .set_scl = octeon_i2c_set_scl, + .get_sda = octeon_i2c_get_sda, + .prepare_recovery = octeon_i2c_prepare_recovery, + .unprepare_recovery = octeon_i2c_unprepare_recovery, +}; - for (tries = 10; tries; tries--) { - udelay(1); - status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT); - if (status == STAT_IDLE) - return 0; - } - dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status); - return -EIO; +static u32 octeon_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL; } +static const struct i2c_algorithm octeon_i2c_algo = { + .master_xfer = octeon_i2c_xfer, + .functionality = octeon_i2c_functionality, +}; + +static struct i2c_adapter octeon_i2c_ops = { + .owner = THIS_MODULE, + .name = "OCTEON adapter", + .algo = &octeon_i2c_algo, +}; + static int octeon_i2c_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; + int irq, result = 0, hlc_irq = 0; struct resource *res_mem; struct octeon_i2c *i2c; - int irq, result = 0; - - /* All adaptors have an irq. */ - irq = platform_get_irq(pdev, 0); - if (irq < 0) - return irq; + bool cn78xx_style; + + cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi"); + if (cn78xx_style) { + hlc_irq = platform_get_irq(pdev, 0); + if (hlc_irq < 0) + return hlc_irq; + + irq = platform_get_irq(pdev, 2); + if (irq < 0) + return irq; + } else { + /* All adaptors have an irq. */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + } i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); if (!i2c) { @@ -537,6 +1160,31 @@ static int octeon_i2c_probe(struct platform_device *pdev) i2c->irq = irq; + if (cn78xx_style) { + i2c->hlc_irq = hlc_irq; + + i2c->int_enable = octeon_i2c_int_enable78; + i2c->int_disable = octeon_i2c_int_disable78; + i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78; + i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78; + + irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN); + irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN); + + result = devm_request_irq(&pdev->dev, i2c->hlc_irq, + octeon_i2c_hlc_isr78, 0, + DRV_NAME, i2c); + if (result < 0) { + dev_err(i2c->dev, "failed to attach interrupt\n"); + goto out; + } + } else { + i2c->int_enable = octeon_i2c_int_enable; + i2c->int_disable = octeon_i2c_int_disable; + i2c->hlc_int_enable = octeon_i2c_hlc_int_enable; + i2c->hlc_int_disable = octeon_i2c_int_disable; + } + result = devm_request_irq(&pdev->dev, i2c->irq, octeon_i2c_isr, 0, DRV_NAME, i2c); if (result < 0) { @@ -544,6 +1192,9 @@ static int octeon_i2c_probe(struct platform_device *pdev) goto out; } + if (OCTEON_IS_MODEL(OCTEON_CN38XX)) + i2c->broken_irq_check = true; + result = octeon_i2c_init_lowlevel(i2c); if (result) { dev_err(i2c->dev, "init low level failed\n"); @@ -553,6 +1204,9 @@ static int octeon_i2c_probe(struct platform_device *pdev) octeon_i2c_set_clock(i2c); i2c->adap = octeon_i2c_ops; + i2c->adap.timeout = msecs_to_jiffies(2); + i2c->adap.retries = 5; + i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info; i2c->adap.dev.parent = &pdev->dev; i2c->adap.dev.of_node = node; i2c_set_adapdata(&i2c->adap, i2c); @@ -580,6 +1234,7 @@ static int octeon_i2c_remove(struct platform_device *pdev) static const struct of_device_id octeon_i2c_match[] = { { .compatible = "cavium,octeon-3860-twsi", }, + { .compatible = "cavium,octeon-7890-twsi", }, {}, }; MODULE_DEVICE_TABLE(of, octeon_i2c_match); |