| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| James Hogan | 5197 | 87.91% | 2 | 10.00% |
| Ed Blake | 350 | 5.92% | 1 | 5.00% |
| Sifan Naeem | 329 | 5.56% | 11 | 55.00% |
| Kees Cook | 14 | 0.24% | 1 | 5.00% |
| Nicholas Mc Guire | 11 | 0.19% | 1 | 5.00% |
| Wolfram Sang | 4 | 0.07% | 1 | 5.00% |
| Geliang Tang | 3 | 0.05% | 1 | 5.00% |
| Andy Shevchenko | 2 | 0.03% | 1 | 5.00% |
| Thomas Gleixner | 2 | 0.03% | 1 | 5.00% |
| Total | 5912 | 20 |
// SPDX-License-Identifier: GPL-2.0-only /* * I2C adapter for the IMG Serial Control Bus (SCB) IP block. * * Copyright (C) 2009, 2010, 2012, 2014 Imagination Technologies Ltd. * * There are three ways that this I2C controller can be driven: * * - Raw control of the SDA and SCK signals. * * This corresponds to MODE_RAW, which takes control of the signals * directly for a certain number of clock cycles (the INT_TIMING * interrupt can be used for timing). * * - Atomic commands. A low level I2C symbol (such as generate * start/stop/ack/nack bit, generate byte, receive byte, and receive * ACK) is given to the hardware, with detection of completion by bits * in the LINESTAT register. * * This mode of operation is used by MODE_ATOMIC, which uses an I2C * state machine in the interrupt handler to compose/react to I2C * transactions using atomic mode commands, and also by MODE_SEQUENCE, * which emits a simple fixed sequence of atomic mode commands. * * Due to software control, the use of atomic commands usually results * in suboptimal use of the bus, with gaps between the I2C symbols while * the driver decides what to do next. * * - Automatic mode. A bus address, and whether to read/write is * specified, and the hardware takes care of the I2C state machine, * using a FIFO to send/receive bytes of data to an I2C slave. The * driver just has to keep the FIFO drained or filled in response to the * appropriate FIFO interrupts. * * This corresponds to MODE_AUTOMATIC, which manages the FIFOs and deals * with control of repeated start bits between I2C messages. * * Use of automatic mode and the FIFO can make much more efficient use * of the bus compared to individual atomic commands, with potentially * no wasted time between I2C symbols or I2C messages. * * In most cases MODE_AUTOMATIC is used, however if any of the messages in * a transaction are zero byte writes (e.g. used by i2cdetect for probing * the bus), MODE_ATOMIC must be used since automatic mode is normally * started by the writing of data into the FIFO. * * The other modes are used in specific circumstances where MODE_ATOMIC and * MODE_AUTOMATIC aren't appropriate. MODE_RAW is used to implement a bus * recovery routine. MODE_SEQUENCE is used to reset the bus and make sure * it is in a sane state. * * Notice that the driver implements a timer-based timeout mechanism. * The reason for this mechanism is to reduce the number of interrupts * received in automatic mode. * * The driver would get a slave event and transaction done interrupts for * each atomic mode command that gets completed. However, these events are * not needed in automatic mode, becase those atomic mode commands are * managed automatically by the hardware. * * In practice, normal I2C transactions will be complete well before you * get the timer interrupt, as the timer is re-scheduled during FIFO * maintenance and disabled after the transaction is complete. * * In this way normal automatic mode operation isn't impacted by * unnecessary interrupts, but the exceptional abort condition can still be * detected (with a slight delay). */ #include <linux/bitops.h> #include <linux/clk.h> #include <linux/completion.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/slab.h> #include <linux/timer.h> /* Register offsets */ #define SCB_STATUS_REG 0x00 #define SCB_OVERRIDE_REG 0x04 #define SCB_READ_ADDR_REG 0x08 #define SCB_READ_COUNT_REG 0x0c #define SCB_WRITE_ADDR_REG 0x10 #define SCB_READ_DATA_REG 0x14 #define SCB_WRITE_DATA_REG 0x18 #define SCB_FIFO_STATUS_REG 0x1c #define SCB_CONTROL_SOFT_RESET 0x1f #define SCB_CLK_SET_REG 0x3c #define SCB_INT_STATUS_REG 0x40 #define SCB_INT_CLEAR_REG 0x44 #define SCB_INT_MASK_REG 0x48 #define SCB_CONTROL_REG 0x4c #define SCB_TIME_TPL_REG 0x50 #define SCB_TIME_TPH_REG 0x54 #define SCB_TIME_TP2S_REG 0x58 #define SCB_TIME_TBI_REG 0x60 #define SCB_TIME_TSL_REG 0x64 #define SCB_TIME_TDL_REG 0x68 #define SCB_TIME_TSDL_REG 0x6c #define SCB_TIME_TSDH_REG 0x70 #define SCB_READ_XADDR_REG 0x74 #define SCB_WRITE_XADDR_REG 0x78 #define SCB_WRITE_COUNT_REG 0x7c #define SCB_CORE_REV_REG 0x80 #define SCB_TIME_TCKH_REG 0x84 #define SCB_TIME_TCKL_REG 0x88 #define SCB_FIFO_FLUSH_REG 0x8c #define SCB_READ_FIFO_REG 0x94 #define SCB_CLEAR_REG 0x98 /* SCB_CONTROL_REG bits */ #define SCB_CONTROL_CLK_ENABLE 0x1e0 #define SCB_CONTROL_TRANSACTION_HALT 0x200 #define FIFO_READ_FULL BIT(0) #define FIFO_READ_EMPTY BIT(1) #define FIFO_WRITE_FULL BIT(2) #define FIFO_WRITE_EMPTY BIT(3) /* SCB_CLK_SET_REG bits */ #define SCB_FILT_DISABLE BIT(31) #define SCB_FILT_BYPASS BIT(30) #define SCB_FILT_INC_MASK 0x7f #define SCB_FILT_INC_SHIFT 16 #define SCB_INC_MASK 0x7f #define SCB_INC_SHIFT 8 /* SCB_INT_*_REG bits */ #define INT_BUS_INACTIVE BIT(0) #define INT_UNEXPECTED_START BIT(1) #define INT_SCLK_LOW_TIMEOUT BIT(2) #define INT_SDAT_LOW_TIMEOUT BIT(3) #define INT_WRITE_ACK_ERR BIT(4) #define INT_ADDR_ACK_ERR BIT(5) #define INT_FIFO_FULL BIT(9) #define INT_FIFO_FILLING BIT(10) #define INT_FIFO_EMPTY BIT(11) #define INT_FIFO_EMPTYING BIT(12) #define INT_TRANSACTION_DONE BIT(15) #define INT_SLAVE_EVENT BIT(16) #define INT_MASTER_HALTED BIT(17) #define INT_TIMING BIT(18) #define INT_STOP_DETECTED BIT(19) #define INT_FIFO_FULL_FILLING (INT_FIFO_FULL | INT_FIFO_FILLING) /* Level interrupts need clearing after handling instead of before */ #define INT_LEVEL 0x01e00 /* Don't allow any interrupts while the clock may be off */ #define INT_ENABLE_MASK_INACTIVE 0x00000 /* Interrupt masks for the different driver modes */ #define INT_ENABLE_MASK_RAW INT_TIMING #define INT_ENABLE_MASK_ATOMIC (INT_TRANSACTION_DONE | \ INT_SLAVE_EVENT | \ INT_ADDR_ACK_ERR | \ INT_WRITE_ACK_ERR) #define INT_ENABLE_MASK_AUTOMATIC (INT_SCLK_LOW_TIMEOUT | \ INT_ADDR_ACK_ERR | \ INT_WRITE_ACK_ERR | \ INT_FIFO_FULL | \ INT_FIFO_FILLING | \ INT_FIFO_EMPTY | \ INT_MASTER_HALTED | \ INT_STOP_DETECTED) #define INT_ENABLE_MASK_WAITSTOP (INT_SLAVE_EVENT | \ INT_ADDR_ACK_ERR | \ INT_WRITE_ACK_ERR) /* SCB_STATUS_REG fields */ #define LINESTAT_SCLK_LINE_STATUS BIT(0) #define LINESTAT_SCLK_EN BIT(1) #define LINESTAT_SDAT_LINE_STATUS BIT(2) #define LINESTAT_SDAT_EN BIT(3) #define LINESTAT_DET_START_STATUS BIT(4) #define LINESTAT_DET_STOP_STATUS BIT(5) #define LINESTAT_DET_ACK_STATUS BIT(6) #define LINESTAT_DET_NACK_STATUS BIT(7) #define LINESTAT_BUS_IDLE BIT(8) #define LINESTAT_T_DONE_STATUS BIT(9) #define LINESTAT_SCLK_OUT_STATUS BIT(10) #define LINESTAT_SDAT_OUT_STATUS BIT(11) #define LINESTAT_GEN_LINE_MASK_STATUS BIT(12) #define LINESTAT_START_BIT_DET BIT(13) #define LINESTAT_STOP_BIT_DET BIT(14) #define LINESTAT_ACK_DET BIT(15) #define LINESTAT_NACK_DET BIT(16) #define LINESTAT_INPUT_HELD_V BIT(17) #define LINESTAT_ABORT_DET BIT(18) #define LINESTAT_ACK_OR_NACK_DET (LINESTAT_ACK_DET | LINESTAT_NACK_DET) #define LINESTAT_INPUT_DATA 0xff000000 #define LINESTAT_INPUT_DATA_SHIFT 24 #define LINESTAT_CLEAR_SHIFT 13 #define LINESTAT_LATCHED (0x3f << LINESTAT_CLEAR_SHIFT) /* SCB_OVERRIDE_REG fields */ #define OVERRIDE_SCLK_OVR BIT(0) #define OVERRIDE_SCLKEN_OVR BIT(1) #define OVERRIDE_SDAT_OVR BIT(2) #define OVERRIDE_SDATEN_OVR BIT(3) #define OVERRIDE_MASTER BIT(9) #define OVERRIDE_LINE_OVR_EN BIT(10) #define OVERRIDE_DIRECT BIT(11) #define OVERRIDE_CMD_SHIFT 4 #define OVERRIDE_CMD_MASK 0x1f #define OVERRIDE_DATA_SHIFT 24 #define OVERRIDE_SCLK_DOWN (OVERRIDE_LINE_OVR_EN | \ OVERRIDE_SCLKEN_OVR) #define OVERRIDE_SCLK_UP (OVERRIDE_LINE_OVR_EN | \ OVERRIDE_SCLKEN_OVR | \ OVERRIDE_SCLK_OVR) #define OVERRIDE_SDAT_DOWN (OVERRIDE_LINE_OVR_EN | \ OVERRIDE_SDATEN_OVR) #define OVERRIDE_SDAT_UP (OVERRIDE_LINE_OVR_EN | \ OVERRIDE_SDATEN_OVR | \ OVERRIDE_SDAT_OVR) /* OVERRIDE_CMD values */ #define CMD_PAUSE 0x00 #define CMD_GEN_DATA 0x01 #define CMD_GEN_START 0x02 #define CMD_GEN_STOP 0x03 #define CMD_GEN_ACK 0x04 #define CMD_GEN_NACK 0x05 #define CMD_RET_DATA 0x08 #define CMD_RET_ACK 0x09 /* Fixed timing values */ #define TIMEOUT_TBI 0x0 #define TIMEOUT_TSL 0xffff #define TIMEOUT_TDL 0x0 /* Transaction timeout */ #define IMG_I2C_TIMEOUT (msecs_to_jiffies(1000)) /* * Worst incs are 1 (innacurate) and 16*256 (irregular). * So a sensible inc is the logarithmic mean: 64 (2^6), which is * in the middle of the valid range (0-127). */ #define SCB_OPT_INC 64 /* Setup the clock enable filtering for 25 ns */ #define SCB_FILT_GLITCH 25 /* * Bits to return from interrupt handler functions for different modes. * This delays completion until we've finished with the registers, so that the * function waiting for completion can safely disable the clock to save power. */ #define ISR_COMPLETE_M BIT(31) #define ISR_FATAL_M BIT(30) #define ISR_WAITSTOP BIT(29) #define ISR_STATUS_M 0x0000ffff /* contains +ve errno */ #define ISR_COMPLETE(err) (ISR_COMPLETE_M | (ISR_STATUS_M & (err))) #define ISR_FATAL(err) (ISR_COMPLETE(err) | ISR_FATAL_M) #define IMG_I2C_PM_TIMEOUT 1000 /* ms */ enum img_i2c_mode { MODE_INACTIVE, MODE_RAW, MODE_ATOMIC, MODE_AUTOMATIC, MODE_SEQUENCE, MODE_FATAL, MODE_WAITSTOP, MODE_SUSPEND, }; /* Timing parameters for i2c modes (in ns) */ struct img_i2c_timings { const char *name; unsigned int max_bitrate; unsigned int tckh, tckl, tsdh, tsdl; unsigned int tp2s, tpl, tph; }; /* The timings array must be ordered from slower to faster */ static struct img_i2c_timings timings[] = { /* Standard mode */ { .name = "standard", .max_bitrate = I2C_MAX_STANDARD_MODE_FREQ, .tckh = 4000, .tckl = 4700, .tsdh = 4700, .tsdl = 8700, .tp2s = 4700, .tpl = 4700, .tph = 4000, }, /* Fast mode */ { .name = "fast", .max_bitrate = I2C_MAX_FAST_MODE_FREQ, .tckh = 600, .tckl = 1300, .tsdh = 600, .tsdl = 1200, .tp2s = 1300, .tpl = 600, .tph = 600, }, }; /* Reset dance */ static u8 img_i2c_reset_seq[] = { CMD_GEN_START, CMD_GEN_DATA, 0xff, CMD_RET_ACK, CMD_GEN_START, CMD_GEN_STOP, 0 }; /* Just issue a stop (after an abort condition) */ static u8 img_i2c_stop_seq[] = { CMD_GEN_STOP, 0 }; /* We're interested in different interrupts depending on the mode */ static unsigned int img_i2c_int_enable_by_mode[] = { [MODE_INACTIVE] = INT_ENABLE_MASK_INACTIVE, [MODE_RAW] = INT_ENABLE_MASK_RAW, [MODE_ATOMIC] = INT_ENABLE_MASK_ATOMIC, [MODE_AUTOMATIC] = INT_ENABLE_MASK_AUTOMATIC, [MODE_SEQUENCE] = INT_ENABLE_MASK_ATOMIC, [MODE_FATAL] = 0, [MODE_WAITSTOP] = INT_ENABLE_MASK_WAITSTOP, [MODE_SUSPEND] = 0, }; /* Atomic command names */ static const char * const img_i2c_atomic_cmd_names[] = { [CMD_PAUSE] = "PAUSE", [CMD_GEN_DATA] = "GEN_DATA", [CMD_GEN_START] = "GEN_START", [CMD_GEN_STOP] = "GEN_STOP", [CMD_GEN_ACK] = "GEN_ACK", [CMD_GEN_NACK] = "GEN_NACK", [CMD_RET_DATA] = "RET_DATA", [CMD_RET_ACK] = "RET_ACK", }; struct img_i2c { struct i2c_adapter adap; void __iomem *base; /* * The scb core clock is used to get the input frequency, and to disable * it after every set of transactions to save some power. */ struct clk *scb_clk, *sys_clk; unsigned int bitrate; bool need_wr_rd_fence; /* state */ struct completion msg_complete; spinlock_t lock; /* lock before doing anything with the state */ struct i2c_msg msg; /* After the last transaction, wait for a stop bit */ bool last_msg; int msg_status; enum img_i2c_mode mode; u32 int_enable; /* depends on mode */ u32 line_status; /* line status over command */ /* * To avoid slave event interrupts in automatic mode, use a timer to * poll the abort condition if we don't get an interrupt for too long. */ struct timer_list check_timer; bool t_halt; /* atomic mode state */ bool at_t_done; bool at_slave_event; int at_cur_cmd; u8 at_cur_data; /* Sequence: either reset or stop. See img_i2c_sequence. */ u8 *seq; /* raw mode */ unsigned int raw_timeout; }; static int img_i2c_runtime_suspend(struct device *dev); static int img_i2c_runtime_resume(struct device *dev); static void img_i2c_writel(struct img_i2c *i2c, u32 offset, u32 value) { writel(value, i2c->base + offset); } static u32 img_i2c_readl(struct img_i2c *i2c, u32 offset) { return readl(i2c->base + offset); } /* * The code to read from the master read fifo, and write to the master * write fifo, checks a bit in an SCB register before every byte to * ensure that the fifo is not full (write fifo) or empty (read fifo). * Due to clock domain crossing inside the SCB block the updated value * of this bit is only visible after 2 cycles. * * The scb_wr_rd_fence() function does 2 dummy writes (to the read-only * revision register), and it's called after reading from or writing to the * fifos to ensure that subsequent reads of the fifo status bits do not read * stale values. */ static void img_i2c_wr_rd_fence(struct img_i2c *i2c) { if (i2c->need_wr_rd_fence) { img_i2c_writel(i2c, SCB_CORE_REV_REG, 0); img_i2c_writel(i2c, SCB_CORE_REV_REG, 0); } } static void img_i2c_switch_mode(struct img_i2c *i2c, enum img_i2c_mode mode) { i2c->mode = mode; i2c->int_enable = img_i2c_int_enable_by_mode[mode]; i2c->line_status = 0; } static void img_i2c_raw_op(struct img_i2c *i2c) { i2c->raw_timeout = 0; img_i2c_writel(i2c, SCB_OVERRIDE_REG, OVERRIDE_SCLKEN_OVR | OVERRIDE_SDATEN_OVR | OVERRIDE_MASTER | OVERRIDE_LINE_OVR_EN | OVERRIDE_DIRECT | ((i2c->at_cur_cmd & OVERRIDE_CMD_MASK) << OVERRIDE_CMD_SHIFT) | (i2c->at_cur_data << OVERRIDE_DATA_SHIFT)); } static const char *img_i2c_atomic_op_name(unsigned int cmd) { if (unlikely(cmd >= ARRAY_SIZE(img_i2c_atomic_cmd_names))) return "UNKNOWN"; return img_i2c_atomic_cmd_names[cmd]; } /* Send a single atomic mode command to the hardware */ static void img_i2c_atomic_op(struct img_i2c *i2c, int cmd, u8 data) { i2c->at_cur_cmd = cmd; i2c->at_cur_data = data; /* work around lack of data setup time when generating data */ if (cmd == CMD_GEN_DATA && i2c->mode == MODE_ATOMIC) { u32 line_status = img_i2c_readl(i2c, SCB_STATUS_REG); if (line_status & LINESTAT_SDAT_LINE_STATUS && !(data & 0x80)) { /* hold the data line down for a moment */ img_i2c_switch_mode(i2c, MODE_RAW); img_i2c_raw_op(i2c); return; } } dev_dbg(i2c->adap.dev.parent, "atomic cmd=%s (%d) data=%#x\n", img_i2c_atomic_op_name(cmd), cmd, data); i2c->at_t_done = (cmd == CMD_RET_DATA || cmd == CMD_RET_ACK); i2c->at_slave_event = false; i2c->line_status = 0; img_i2c_writel(i2c, SCB_OVERRIDE_REG, ((cmd & OVERRIDE_CMD_MASK) << OVERRIDE_CMD_SHIFT) | OVERRIDE_MASTER | OVERRIDE_DIRECT | (data << OVERRIDE_DATA_SHIFT)); } /* Start a transaction in atomic mode */ static void img_i2c_atomic_start(struct img_i2c *i2c) { img_i2c_switch_mode(i2c, MODE_ATOMIC); img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); img_i2c_atomic_op(i2c, CMD_GEN_START, 0x00); } static void img_i2c_soft_reset(struct img_i2c *i2c) { i2c->t_halt = false; img_i2c_writel(i2c, SCB_CONTROL_REG, 0); img_i2c_writel(i2c, SCB_CONTROL_REG, SCB_CONTROL_CLK_ENABLE | SCB_CONTROL_SOFT_RESET); } /* * Enable or release transaction halt for control of repeated starts. * In version 3.3 of the IP when transaction halt is set, an interrupt * will be generated after each byte of a transfer instead of after * every transfer but before the stop bit. * Due to this behaviour we have to be careful that every time we * release the transaction halt we have to re-enable it straight away * so that we only process a single byte, not doing so will result in * all remaining bytes been processed and a stop bit being issued, * which will prevent us having a repeated start. */ static void img_i2c_transaction_halt(struct img_i2c *i2c, bool t_halt) { u32 val; if (i2c->t_halt == t_halt) return; i2c->t_halt = t_halt; val = img_i2c_readl(i2c, SCB_CONTROL_REG); if (t_halt) val |= SCB_CONTROL_TRANSACTION_HALT; else val &= ~SCB_CONTROL_TRANSACTION_HALT; img_i2c_writel(i2c, SCB_CONTROL_REG, val); } /* Drain data from the FIFO into the buffer (automatic mode) */ static void img_i2c_read_fifo(struct img_i2c *i2c) { while (i2c->msg.len) { u32 fifo_status; u8 data; img_i2c_wr_rd_fence(i2c); fifo_status = img_i2c_readl(i2c, SCB_FIFO_STATUS_REG); if (fifo_status & FIFO_READ_EMPTY) break; data = img_i2c_readl(i2c, SCB_READ_DATA_REG); *i2c->msg.buf = data; img_i2c_writel(i2c, SCB_READ_FIFO_REG, 0xff); i2c->msg.len--; i2c->msg.buf++; } } /* Fill the FIFO with data from the buffer (automatic mode) */ static void img_i2c_write_fifo(struct img_i2c *i2c) { while (i2c->msg.len) { u32 fifo_status; img_i2c_wr_rd_fence(i2c); fifo_status = img_i2c_readl(i2c, SCB_FIFO_STATUS_REG); if (fifo_status & FIFO_WRITE_FULL) break; img_i2c_writel(i2c, SCB_WRITE_DATA_REG, *i2c->msg.buf); i2c->msg.len--; i2c->msg.buf++; } /* Disable fifo emptying interrupt if nothing more to write */ if (!i2c->msg.len) i2c->int_enable &= ~INT_FIFO_EMPTYING; } /* Start a read transaction in automatic mode */ static void img_i2c_read(struct img_i2c *i2c) { img_i2c_switch_mode(i2c, MODE_AUTOMATIC); if (!i2c->last_msg) i2c->int_enable |= INT_SLAVE_EVENT; img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); img_i2c_writel(i2c, SCB_READ_ADDR_REG, i2c->msg.addr); img_i2c_writel(i2c, SCB_READ_COUNT_REG, i2c->msg.len); mod_timer(&i2c->check_timer, jiffies + msecs_to_jiffies(1)); } /* Start a write transaction in automatic mode */ static void img_i2c_write(struct img_i2c *i2c) { img_i2c_switch_mode(i2c, MODE_AUTOMATIC); if (!i2c->last_msg) i2c->int_enable |= INT_SLAVE_EVENT; img_i2c_writel(i2c, SCB_WRITE_ADDR_REG, i2c->msg.addr); img_i2c_writel(i2c, SCB_WRITE_COUNT_REG, i2c->msg.len); mod_timer(&i2c->check_timer, jiffies + msecs_to_jiffies(1)); img_i2c_write_fifo(i2c); /* img_i2c_write_fifo() may modify int_enable */ img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); } /* * Indicate that the transaction is complete. This is called from the * ISR to wake up the waiting thread, after which the ISR must not * access any more SCB registers. */ static void img_i2c_complete_transaction(struct img_i2c *i2c, int status) { img_i2c_switch_mode(i2c, MODE_INACTIVE); if (status) { i2c->msg_status = status; img_i2c_transaction_halt(i2c, false); } complete(&i2c->msg_complete); } static unsigned int img_i2c_raw_atomic_delay_handler(struct img_i2c *i2c, u32 int_status, u32 line_status) { /* Stay in raw mode for this, so we don't just loop infinitely */ img_i2c_atomic_op(i2c, i2c->at_cur_cmd, i2c->at_cur_data); img_i2c_switch_mode(i2c, MODE_ATOMIC); return 0; } static unsigned int img_i2c_raw(struct img_i2c *i2c, u32 int_status, u32 line_status) { if (int_status & INT_TIMING) { if (i2c->raw_timeout == 0) return img_i2c_raw_atomic_delay_handler(i2c, int_status, line_status); --i2c->raw_timeout; } return 0; } static unsigned int img_i2c_sequence(struct img_i2c *i2c, u32 int_status) { static const unsigned int continue_bits[] = { [CMD_GEN_START] = LINESTAT_START_BIT_DET, [CMD_GEN_DATA] = LINESTAT_INPUT_HELD_V, [CMD_RET_ACK] = LINESTAT_ACK_DET | LINESTAT_NACK_DET, [CMD_RET_DATA] = LINESTAT_INPUT_HELD_V, [CMD_GEN_STOP] = LINESTAT_STOP_BIT_DET, }; int next_cmd = -1; u8 next_data = 0x00; if (int_status & INT_SLAVE_EVENT) i2c->at_slave_event = true; if (int_status & INT_TRANSACTION_DONE) i2c->at_t_done = true; if (!i2c->at_slave_event || !i2c->at_t_done) return 0; /* wait if no continue bits are set */ if (i2c->at_cur_cmd >= 0 && i2c->at_cur_cmd < ARRAY_SIZE(continue_bits)) { unsigned int cont_bits = continue_bits[i2c->at_cur_cmd]; if (cont_bits) { cont_bits |= LINESTAT_ABORT_DET; if (!(i2c->line_status & cont_bits)) return 0; } } /* follow the sequence of commands in i2c->seq */ next_cmd = *i2c->seq; /* stop on a nil */ if (!next_cmd) { img_i2c_writel(i2c, SCB_OVERRIDE_REG, 0); return ISR_COMPLETE(0); } /* when generating data, the next byte is the data */ if (next_cmd == CMD_GEN_DATA) { ++i2c->seq; next_data = *i2c->seq; } ++i2c->seq; img_i2c_atomic_op(i2c, next_cmd, next_data); return 0; } static void img_i2c_reset_start(struct img_i2c *i2c) { /* Initiate the magic dance */ img_i2c_switch_mode(i2c, MODE_SEQUENCE); img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); i2c->seq = img_i2c_reset_seq; i2c->at_slave_event = true; i2c->at_t_done = true; i2c->at_cur_cmd = -1; /* img_i2c_reset_seq isn't empty so the following won't fail */ img_i2c_sequence(i2c, 0); } static void img_i2c_stop_start(struct img_i2c *i2c) { /* Initiate a stop bit sequence */ img_i2c_switch_mode(i2c, MODE_SEQUENCE); img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); i2c->seq = img_i2c_stop_seq; i2c->at_slave_event = true; i2c->at_t_done = true; i2c->at_cur_cmd = -1; /* img_i2c_stop_seq isn't empty so the following won't fail */ img_i2c_sequence(i2c, 0); } static unsigned int img_i2c_atomic(struct img_i2c *i2c, u32 int_status, u32 line_status) { int next_cmd = -1; u8 next_data = 0x00; if (int_status & INT_SLAVE_EVENT) i2c->at_slave_event = true; if (int_status & INT_TRANSACTION_DONE) i2c->at_t_done = true; if (!i2c->at_slave_event || !i2c->at_t_done) goto next_atomic_cmd; if (i2c->line_status & LINESTAT_ABORT_DET) { dev_dbg(i2c->adap.dev.parent, "abort condition detected\n"); next_cmd = CMD_GEN_STOP; i2c->msg_status = -EIO; goto next_atomic_cmd; } /* i2c->at_cur_cmd may have completed */ switch (i2c->at_cur_cmd) { case CMD_GEN_START: next_cmd = CMD_GEN_DATA; next_data = i2c_8bit_addr_from_msg(&i2c->msg); break; case CMD_GEN_DATA: if (i2c->line_status & LINESTAT_INPUT_HELD_V) next_cmd = CMD_RET_ACK; break; case CMD_RET_ACK: if (i2c->line_status & LINESTAT_ACK_DET || (i2c->line_status & LINESTAT_NACK_DET && i2c->msg.flags & I2C_M_IGNORE_NAK)) { if (i2c->msg.len == 0) { next_cmd = CMD_GEN_STOP; } else if (i2c->msg.flags & I2C_M_RD) { next_cmd = CMD_RET_DATA; } else { next_cmd = CMD_GEN_DATA; next_data = *i2c->msg.buf; --i2c->msg.len; ++i2c->msg.buf; } } else if (i2c->line_status & LINESTAT_NACK_DET) { i2c->msg_status = -EIO; next_cmd = CMD_GEN_STOP; } break; case CMD_RET_DATA: if (i2c->line_status & LINESTAT_INPUT_HELD_V) { *i2c->msg.buf = (i2c->line_status & LINESTAT_INPUT_DATA) >> LINESTAT_INPUT_DATA_SHIFT; --i2c->msg.len; ++i2c->msg.buf; if (i2c->msg.len) next_cmd = CMD_GEN_ACK; else next_cmd = CMD_GEN_NACK; } break; case CMD_GEN_ACK: if (i2c->line_status & LINESTAT_ACK_DET) { next_cmd = CMD_RET_DATA; } else { i2c->msg_status = -EIO; next_cmd = CMD_GEN_STOP; } break; case CMD_GEN_NACK: next_cmd = CMD_GEN_STOP; break; case CMD_GEN_STOP: img_i2c_writel(i2c, SCB_OVERRIDE_REG, 0); return ISR_COMPLETE(0); default: dev_err(i2c->adap.dev.parent, "bad atomic command %d\n", i2c->at_cur_cmd); i2c->msg_status = -EIO; next_cmd = CMD_GEN_STOP; break; } next_atomic_cmd: if (next_cmd != -1) { /* don't actually stop unless we're the last transaction */ if (next_cmd == CMD_GEN_STOP && !i2c->msg_status && !i2c->last_msg) return ISR_COMPLETE(0); img_i2c_atomic_op(i2c, next_cmd, next_data); } return 0; } /* * Timer function to check if something has gone wrong in automatic mode (so we * don't have to handle so many interrupts just to catch an exception). */ static void img_i2c_check_timer(struct timer_list *t) { struct img_i2c *i2c = from_timer(i2c, t, check_timer); unsigned long flags; unsigned int line_status; spin_lock_irqsave(&i2c->lock, flags); line_status = img_i2c_readl(i2c, SCB_STATUS_REG); /* check for an abort condition */ if (line_status & LINESTAT_ABORT_DET) { dev_dbg(i2c->adap.dev.parent, "abort condition detected by check timer\n"); /* enable slave event interrupt mask to trigger irq */ img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable | INT_SLAVE_EVENT); } spin_unlock_irqrestore(&i2c->lock, flags); } static unsigned int img_i2c_auto(struct img_i2c *i2c, unsigned int int_status, unsigned int line_status) { if (int_status & (INT_WRITE_ACK_ERR | INT_ADDR_ACK_ERR)) return ISR_COMPLETE(EIO); if (line_status & LINESTAT_ABORT_DET) { dev_dbg(i2c->adap.dev.parent, "abort condition detected\n"); /* empty the read fifo */ if ((i2c->msg.flags & I2C_M_RD) && (int_status & INT_FIFO_FULL_FILLING)) img_i2c_read_fifo(i2c); /* use atomic mode and try to force a stop bit */ i2c->msg_status = -EIO; img_i2c_stop_start(i2c); return 0; } /* Enable transaction halt on start bit */ if (!i2c->last_msg && line_status & LINESTAT_START_BIT_DET) { img_i2c_transaction_halt(i2c, !i2c->last_msg); /* we're no longer interested in the slave event */ i2c->int_enable &= ~INT_SLAVE_EVENT; } mod_timer(&i2c->check_timer, jiffies + msecs_to_jiffies(1)); if (int_status & INT_STOP_DETECTED) { /* Drain remaining data in FIFO and complete transaction */ if (i2c->msg.flags & I2C_M_RD) img_i2c_read_fifo(i2c); return ISR_COMPLETE(0); } if (i2c->msg.flags & I2C_M_RD) { if (int_status & (INT_FIFO_FULL_FILLING | INT_MASTER_HALTED)) { img_i2c_read_fifo(i2c); if (i2c->msg.len == 0) return ISR_WAITSTOP; } } else { if (int_status & (INT_FIFO_EMPTY | INT_MASTER_HALTED)) { if ((int_status & INT_FIFO_EMPTY) && i2c->msg.len == 0) return ISR_WAITSTOP; img_i2c_write_fifo(i2c); } } if (int_status & INT_MASTER_HALTED) { /* * Release and then enable transaction halt, to * allow only a single byte to proceed. */ img_i2c_transaction_halt(i2c, false); img_i2c_transaction_halt(i2c, !i2c->last_msg); } return 0; } static irqreturn_t img_i2c_isr(int irq, void *dev_id) { struct img_i2c *i2c = (struct img_i2c *)dev_id; u32 int_status, line_status; /* We handle transaction completion AFTER accessing registers */ unsigned int hret; /* Read interrupt status register. */ int_status = img_i2c_readl(i2c, SCB_INT_STATUS_REG); /* Clear detected interrupts. */ img_i2c_writel(i2c, SCB_INT_CLEAR_REG, int_status); /* * Read line status and clear it until it actually is clear. We have * to be careful not to lose any line status bits that get latched. */ line_status = img_i2c_readl(i2c, SCB_STATUS_REG); if (line_status & LINESTAT_LATCHED) { img_i2c_writel(i2c, SCB_CLEAR_REG, (line_status & LINESTAT_LATCHED) >> LINESTAT_CLEAR_SHIFT); img_i2c_wr_rd_fence(i2c); } spin_lock(&i2c->lock); /* Keep track of line status bits received */ i2c->line_status &= ~LINESTAT_INPUT_DATA; i2c->line_status |= line_status; /* * Certain interrupts indicate that sclk low timeout is not * a problem. If any of these are set, just continue. */ if ((int_status & INT_SCLK_LOW_TIMEOUT) && !(int_status & (INT_SLAVE_EVENT | INT_FIFO_EMPTY | INT_FIFO_FULL))) { dev_crit(i2c->adap.dev.parent, "fatal: clock low timeout occurred %s addr 0x%02x\n", (i2c->msg.flags & I2C_M_RD) ? "reading" : "writing", i2c->msg.addr); hret = ISR_FATAL(EIO); goto out; } if (i2c->mode == MODE_ATOMIC) hret = img_i2c_atomic(i2c, int_status, line_status); else if (i2c->mode == MODE_AUTOMATIC) hret = img_i2c_auto(i2c, int_status, line_status); else if (i2c->mode == MODE_SEQUENCE) hret = img_i2c_sequence(i2c, int_status); else if (i2c->mode == MODE_WAITSTOP && (int_status & INT_SLAVE_EVENT) && (line_status & LINESTAT_STOP_BIT_DET)) hret = ISR_COMPLETE(0); else if (i2c->mode == MODE_RAW) hret = img_i2c_raw(i2c, int_status, line_status); else hret = 0; /* Clear detected level interrupts. */ img_i2c_writel(i2c, SCB_INT_CLEAR_REG, int_status & INT_LEVEL); out: if (hret & ISR_WAITSTOP) { /* * Only wait for stop on last message. * Also we may already have detected the stop bit. */ if (!i2c->last_msg || i2c->line_status & LINESTAT_STOP_BIT_DET) hret = ISR_COMPLETE(0); else img_i2c_switch_mode(i2c, MODE_WAITSTOP); } /* now we've finished using regs, handle transaction completion */ if (hret & ISR_COMPLETE_M) { int status = -(hret & ISR_STATUS_M); img_i2c_complete_transaction(i2c, status); if (hret & ISR_FATAL_M) img_i2c_switch_mode(i2c, MODE_FATAL); } /* Enable interrupts (int_enable may be altered by changing mode) */ img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); spin_unlock(&i2c->lock); return IRQ_HANDLED; } /* Force a bus reset sequence and wait for it to complete */ static int img_i2c_reset_bus(struct img_i2c *i2c) { unsigned long flags; unsigned long time_left; spin_lock_irqsave(&i2c->lock, flags); reinit_completion(&i2c->msg_complete); img_i2c_reset_start(i2c); spin_unlock_irqrestore(&i2c->lock, flags); time_left = wait_for_completion_timeout(&i2c->msg_complete, IMG_I2C_TIMEOUT); if (time_left == 0) return -ETIMEDOUT; return 0; } static int img_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct img_i2c *i2c = i2c_get_adapdata(adap); bool atomic = false; int i, ret; unsigned long time_left; if (i2c->mode == MODE_SUSPEND) { WARN(1, "refusing to service transaction in suspended state\n"); return -EIO; } if (i2c->mode == MODE_FATAL) return -EIO; for (i = 0; i < num; i++) { /* * 0 byte reads are not possible because the slave could try * and pull the data line low, preventing a stop bit. */ if (!msgs[i].len && msgs[i].flags & I2C_M_RD) return -EIO; /* * 0 byte writes are possible and used for probing, but we * cannot do them in automatic mode, so use atomic mode * instead. * * Also, the I2C_M_IGNORE_NAK mode can only be implemented * in atomic mode. */ if (!msgs[i].len || (msgs[i].flags & I2C_M_IGNORE_NAK)) atomic = true; } ret = pm_runtime_get_sync(adap->dev.parent); if (ret < 0) return ret; for (i = 0; i < num; i++) { struct i2c_msg *msg = &msgs[i]; unsigned long flags; spin_lock_irqsave(&i2c->lock, flags); /* * Make a copy of the message struct. We mustn't modify the * original or we'll confuse drivers and i2c-dev. */ i2c->msg = *msg; i2c->msg_status = 0; /* * After the last message we must have waited for a stop bit. * Not waiting can cause problems when the clock is disabled * before the stop bit is sent, and the linux I2C interface * requires separate transfers not to joined with repeated * start. */ i2c->last_msg = (i == num - 1); reinit_completion(&i2c->msg_complete); /* * Clear line status and all interrupts before starting a * transfer, as we may have unserviced interrupts from * previous transfers that might be handled in the context * of the new transfer. */ img_i2c_writel(i2c, SCB_INT_CLEAR_REG, ~0); img_i2c_writel(i2c, SCB_CLEAR_REG, ~0); if (atomic) { img_i2c_atomic_start(i2c); } else { /* * Enable transaction halt if not the last message in * the queue so that we can control repeated starts. */ img_i2c_transaction_halt(i2c, !i2c->last_msg); if (msg->flags & I2C_M_RD) img_i2c_read(i2c); else img_i2c_write(i2c); /* * Release and then enable transaction halt, to * allow only a single byte to proceed. * This doesn't have an effect on the initial transfer * but will allow the following transfers to start * processing if the previous transfer was marked as * complete while the i2c block was halted. */ img_i2c_transaction_halt(i2c, false); img_i2c_transaction_halt(i2c, !i2c->last_msg); } spin_unlock_irqrestore(&i2c->lock, flags); time_left = wait_for_completion_timeout(&i2c->msg_complete, IMG_I2C_TIMEOUT); del_timer_sync(&i2c->check_timer); if (time_left == 0) { dev_err(adap->dev.parent, "i2c transfer timed out\n"); i2c->msg_status = -ETIMEDOUT; break; } if (i2c->msg_status) break; } pm_runtime_mark_last_busy(adap->dev.parent); pm_runtime_put_autosuspend(adap->dev.parent); return i2c->msg_status ? i2c->msg_status : num; } static u32 img_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static const struct i2c_algorithm img_i2c_algo = { .master_xfer = img_i2c_xfer, .functionality = img_i2c_func, }; static int img_i2c_init(struct img_i2c *i2c) { unsigned int clk_khz, bitrate_khz, clk_period, tckh, tckl, tsdh; unsigned int i, data, prescale, inc, int_bitrate, filt; struct img_i2c_timings timing; u32 rev; int ret; ret = pm_runtime_get_sync(i2c->adap.dev.parent); if (ret < 0) return ret; rev = img_i2c_readl(i2c, SCB_CORE_REV_REG); if ((rev & 0x00ffffff) < 0x00020200) { dev_info(i2c->adap.dev.parent, "Unknown hardware revision (%d.%d.%d.%d)\n", (rev >> 24) & 0xff, (rev >> 16) & 0xff, (rev >> 8) & 0xff, rev & 0xff); pm_runtime_mark_last_busy(i2c->adap.dev.parent); pm_runtime_put_autosuspend(i2c->adap.dev.parent); return -EINVAL; } /* Fencing enabled by default. */ i2c->need_wr_rd_fence = true; /* Determine what mode we're in from the bitrate */ timing = timings[0]; for (i = 0; i < ARRAY_SIZE(timings); i++) { if (i2c->bitrate <= timings[i].max_bitrate) { timing = timings[i]; break; } } if (i2c->bitrate > timings[ARRAY_SIZE(timings) - 1].max_bitrate) { dev_warn(i2c->adap.dev.parent, "requested bitrate (%u) is higher than the max bitrate supported (%u)\n", i2c->bitrate, timings[ARRAY_SIZE(timings) - 1].max_bitrate); timing = timings[ARRAY_SIZE(timings) - 1]; i2c->bitrate = timing.max_bitrate; } bitrate_khz = i2c->bitrate / 1000; clk_khz = clk_get_rate(i2c->scb_clk) / 1000; /* Find the prescale that would give us that inc (approx delay = 0) */ prescale = SCB_OPT_INC * clk_khz / (256 * 16 * bitrate_khz); prescale = clamp_t(unsigned int, prescale, 1, 8); clk_khz /= prescale; /* Setup the clock increment value */ inc = (256 * 16 * bitrate_khz) / clk_khz; /* * The clock generation logic allows to filter glitches on the bus. * This filter is able to remove bus glitches shorter than 50ns. * If the clock enable rate is greater than 20 MHz, no filtering * is required, so we need to disable it. * If it's between the 20-40 MHz range, there's no need to divide * the clock to get a filter. */ if (clk_khz < 20000) { filt = SCB_FILT_DISABLE; } else if (clk_khz < 40000) { filt = SCB_FILT_BYPASS; } else { /* Calculate filter clock */ filt = (64000 / ((clk_khz / 1000) * SCB_FILT_GLITCH)); /* Scale up if needed */ if (64000 % ((clk_khz / 1000) * SCB_FILT_GLITCH)) inc++; if (filt > SCB_FILT_INC_MASK) filt = SCB_FILT_INC_MASK; filt = (filt & SCB_FILT_INC_MASK) << SCB_FILT_INC_SHIFT; } data = filt | ((inc & SCB_INC_MASK) << SCB_INC_SHIFT) | (prescale - 1); img_i2c_writel(i2c, SCB_CLK_SET_REG, data); /* Obtain the clock period of the fx16 clock in ns */ clk_period = (256 * 1000000) / (clk_khz * inc); /* Calculate the bitrate in terms of internal clock pulses */ int_bitrate = 1000000 / (bitrate_khz * clk_period); if ((1000000 % (bitrate_khz * clk_period)) >= ((bitrate_khz * clk_period) / 2)) int_bitrate++; /* * Setup clock duty cycle, start with 50% and adjust TCKH and TCKL * values from there if they don't meet minimum timing requirements */ tckh = int_bitrate / 2; tckl = int_bitrate - tckh; /* Adjust TCKH and TCKL values */ data = DIV_ROUND_UP(timing.tckl, clk_period); if (tckl < data) { tckl = data; tckh = int_bitrate - tckl; } if (tckh > 0) --tckh; if (tckl > 0) --tckl; img_i2c_writel(i2c, SCB_TIME_TCKH_REG, tckh); img_i2c_writel(i2c, SCB_TIME_TCKL_REG, tckl); /* Setup TSDH value */ tsdh = DIV_ROUND_UP(timing.tsdh, clk_period); if (tsdh > 1) data = tsdh - 1; else data = 0x01; img_i2c_writel(i2c, SCB_TIME_TSDH_REG, data); /* This value is used later */ tsdh = data; /* Setup TPL value */ data = timing.tpl / clk_period; if (data > 0) --data; img_i2c_writel(i2c, SCB_TIME_TPL_REG, data); /* Setup TPH value */ data = timing.tph / clk_period; if (data > 0) --data; img_i2c_writel(i2c, SCB_TIME_TPH_REG, data); /* Setup TSDL value to TPL + TSDH + 2 */ img_i2c_writel(i2c, SCB_TIME_TSDL_REG, data + tsdh + 2); /* Setup TP2S value */ data = timing.tp2s / clk_period; if (data > 0) --data; img_i2c_writel(i2c, SCB_TIME_TP2S_REG, data); img_i2c_writel(i2c, SCB_TIME_TBI_REG, TIMEOUT_TBI); img_i2c_writel(i2c, SCB_TIME_TSL_REG, TIMEOUT_TSL); img_i2c_writel(i2c, SCB_TIME_TDL_REG, TIMEOUT_TDL); /* Take module out of soft reset and enable clocks */ img_i2c_soft_reset(i2c); /* Disable all interrupts */ img_i2c_writel(i2c, SCB_INT_MASK_REG, 0); /* Clear all interrupts */ img_i2c_writel(i2c, SCB_INT_CLEAR_REG, ~0); /* Clear the scb_line_status events */ img_i2c_writel(i2c, SCB_CLEAR_REG, ~0); /* Enable interrupts */ img_i2c_writel(i2c, SCB_INT_MASK_REG, i2c->int_enable); /* Perform a synchronous sequence to reset the bus */ ret = img_i2c_reset_bus(i2c); pm_runtime_mark_last_busy(i2c->adap.dev.parent); pm_runtime_put_autosuspend(i2c->adap.dev.parent); return ret; } static int img_i2c_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; struct img_i2c *i2c; struct resource *res; int irq, ret; u32 val; i2c = devm_kzalloc(&pdev->dev, sizeof(struct img_i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c->base)) return PTR_ERR(i2c->base); irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "can't get irq number\n"); return irq; } i2c->sys_clk = devm_clk_get(&pdev->dev, "sys"); if (IS_ERR(i2c->sys_clk)) { dev_err(&pdev->dev, "can't get system clock\n"); return PTR_ERR(i2c->sys_clk); } i2c->scb_clk = devm_clk_get(&pdev->dev, "scb"); if (IS_ERR(i2c->scb_clk)) { dev_err(&pdev->dev, "can't get core clock\n"); return PTR_ERR(i2c->scb_clk); } ret = devm_request_irq(&pdev->dev, irq, img_i2c_isr, 0, pdev->name, i2c); if (ret) { dev_err(&pdev->dev, "can't request irq %d\n", irq); return ret; } /* Set up the exception check timer */ timer_setup(&i2c->check_timer, img_i2c_check_timer, 0); i2c->bitrate = timings[0].max_bitrate; if (!of_property_read_u32(node, "clock-frequency", &val)) i2c->bitrate = val; i2c_set_adapdata(&i2c->adap, i2c); i2c->adap.dev.parent = &pdev->dev; i2c->adap.dev.of_node = node; i2c->adap.owner = THIS_MODULE; i2c->adap.algo = &img_i2c_algo; i2c->adap.retries = 5; i2c->adap.nr = pdev->id; snprintf(i2c->adap.name, sizeof(i2c->adap.name), "IMG SCB I2C"); img_i2c_switch_mode(i2c, MODE_INACTIVE); spin_lock_init(&i2c->lock); init_completion(&i2c->msg_complete); platform_set_drvdata(pdev, i2c); pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_I2C_PM_TIMEOUT); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_enable(&pdev->dev); if (!pm_runtime_enabled(&pdev->dev)) { ret = img_i2c_runtime_resume(&pdev->dev); if (ret) return ret; } ret = img_i2c_init(i2c); if (ret) goto rpm_disable; ret = i2c_add_numbered_adapter(&i2c->adap); if (ret < 0) goto rpm_disable; return 0; rpm_disable: if (!pm_runtime_enabled(&pdev->dev)) img_i2c_runtime_suspend(&pdev->dev); pm_runtime_disable(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); return ret; } static int img_i2c_remove(struct platform_device *dev) { struct img_i2c *i2c = platform_get_drvdata(dev); i2c_del_adapter(&i2c->adap); pm_runtime_disable(&dev->dev); if (!pm_runtime_status_suspended(&dev->dev)) img_i2c_runtime_suspend(&dev->dev); return 0; } static int img_i2c_runtime_suspend(struct device *dev) { struct img_i2c *i2c = dev_get_drvdata(dev); clk_disable_unprepare(i2c->scb_clk); clk_disable_unprepare(i2c->sys_clk); return 0; } static int img_i2c_runtime_resume(struct device *dev) { struct img_i2c *i2c = dev_get_drvdata(dev); int ret; ret = clk_prepare_enable(i2c->sys_clk); if (ret) { dev_err(dev, "Unable to enable sys clock\n"); return ret; } ret = clk_prepare_enable(i2c->scb_clk); if (ret) { dev_err(dev, "Unable to enable scb clock\n"); clk_disable_unprepare(i2c->sys_clk); return ret; } return 0; } #ifdef CONFIG_PM_SLEEP static int img_i2c_suspend(struct device *dev) { struct img_i2c *i2c = dev_get_drvdata(dev); int ret; ret = pm_runtime_force_suspend(dev); if (ret) return ret; img_i2c_switch_mode(i2c, MODE_SUSPEND); return 0; } static int img_i2c_resume(struct device *dev) { struct img_i2c *i2c = dev_get_drvdata(dev); int ret; ret = pm_runtime_force_resume(dev); if (ret) return ret; img_i2c_init(i2c); return 0; } #endif /* CONFIG_PM_SLEEP */ static const struct dev_pm_ops img_i2c_pm = { SET_RUNTIME_PM_OPS(img_i2c_runtime_suspend, img_i2c_runtime_resume, NULL) SET_SYSTEM_SLEEP_PM_OPS(img_i2c_suspend, img_i2c_resume) }; static const struct of_device_id img_scb_i2c_match[] = { { .compatible = "img,scb-i2c" }, { } }; MODULE_DEVICE_TABLE(of, img_scb_i2c_match); static struct platform_driver img_scb_i2c_driver = { .driver = { .name = "img-i2c-scb", .of_match_table = img_scb_i2c_match, .pm = &img_i2c_pm, }, .probe = img_i2c_probe, .remove = img_i2c_remove, }; module_platform_driver(img_scb_i2c_driver); MODULE_AUTHOR("James Hogan <jhogan@kernel.org>"); MODULE_DESCRIPTION("IMG host I2C driver"); MODULE_LICENSE("GPL v2");
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