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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/i2c/busses/i2c-rk3x.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-rk3x.c')
-rw-r--r--drivers/i2c/busses/i2c-rk3x.c1369
1 files changed, 1369 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
new file mode 100644
index 000000000..e76ad020a
--- /dev/null
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -0,0 +1,1369 @@
+/*
+ * Driver for I2C adapter in Rockchip RK3xxx SoC
+ *
+ * Max Schwarz <max.schwarz@online.de>
+ * based on the patches by Rockchip Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/wait.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/math64.h>
+
+
+/* Register Map */
+#define REG_CON 0x00 /* control register */
+#define REG_CLKDIV 0x04 /* clock divisor register */
+#define REG_MRXADDR 0x08 /* slave address for REGISTER_TX */
+#define REG_MRXRADDR 0x0c /* slave register address for REGISTER_TX */
+#define REG_MTXCNT 0x10 /* number of bytes to be transmitted */
+#define REG_MRXCNT 0x14 /* number of bytes to be received */
+#define REG_IEN 0x18 /* interrupt enable */
+#define REG_IPD 0x1c /* interrupt pending */
+#define REG_FCNT 0x20 /* finished count */
+
+/* Data buffer offsets */
+#define TXBUFFER_BASE 0x100
+#define RXBUFFER_BASE 0x200
+
+/* REG_CON bits */
+#define REG_CON_EN BIT(0)
+enum {
+ REG_CON_MOD_TX = 0, /* transmit data */
+ REG_CON_MOD_REGISTER_TX, /* select register and restart */
+ REG_CON_MOD_RX, /* receive data */
+ REG_CON_MOD_REGISTER_RX, /* broken: transmits read addr AND writes
+ * register addr */
+};
+#define REG_CON_MOD(mod) ((mod) << 1)
+#define REG_CON_MOD_MASK (BIT(1) | BIT(2))
+#define REG_CON_START BIT(3)
+#define REG_CON_STOP BIT(4)
+#define REG_CON_LASTACK BIT(5) /* 1: send NACK after last received byte */
+#define REG_CON_ACTACK BIT(6) /* 1: stop if NACK is received */
+
+#define REG_CON_TUNING_MASK GENMASK_ULL(15, 8)
+
+#define REG_CON_SDA_CFG(cfg) ((cfg) << 8)
+#define REG_CON_STA_CFG(cfg) ((cfg) << 12)
+#define REG_CON_STO_CFG(cfg) ((cfg) << 14)
+
+/* REG_MRXADDR bits */
+#define REG_MRXADDR_VALID(x) BIT(24 + (x)) /* [x*8+7:x*8] of MRX[R]ADDR valid */
+
+/* REG_IEN/REG_IPD bits */
+#define REG_INT_BTF BIT(0) /* a byte was transmitted */
+#define REG_INT_BRF BIT(1) /* a byte was received */
+#define REG_INT_MBTF BIT(2) /* master data transmit finished */
+#define REG_INT_MBRF BIT(3) /* master data receive finished */
+#define REG_INT_START BIT(4) /* START condition generated */
+#define REG_INT_STOP BIT(5) /* STOP condition generated */
+#define REG_INT_NAKRCV BIT(6) /* NACK received */
+#define REG_INT_ALL 0x7f
+
+/* Constants */
+#define WAIT_TIMEOUT 1000 /* ms */
+#define DEFAULT_SCL_RATE (100 * 1000) /* Hz */
+
+/**
+ * struct i2c_spec_values:
+ * @min_hold_start_ns: min hold time (repeated) START condition
+ * @min_low_ns: min LOW period of the SCL clock
+ * @min_high_ns: min HIGH period of the SCL cloc
+ * @min_setup_start_ns: min set-up time for a repeated START conditio
+ * @max_data_hold_ns: max data hold time
+ * @min_data_setup_ns: min data set-up time
+ * @min_setup_stop_ns: min set-up time for STOP condition
+ * @min_hold_buffer_ns: min bus free time between a STOP and
+ * START condition
+ */
+struct i2c_spec_values {
+ unsigned long min_hold_start_ns;
+ unsigned long min_low_ns;
+ unsigned long min_high_ns;
+ unsigned long min_setup_start_ns;
+ unsigned long max_data_hold_ns;
+ unsigned long min_data_setup_ns;
+ unsigned long min_setup_stop_ns;
+ unsigned long min_hold_buffer_ns;
+};
+
+static const struct i2c_spec_values standard_mode_spec = {
+ .min_hold_start_ns = 4000,
+ .min_low_ns = 4700,
+ .min_high_ns = 4000,
+ .min_setup_start_ns = 4700,
+ .max_data_hold_ns = 3450,
+ .min_data_setup_ns = 250,
+ .min_setup_stop_ns = 4000,
+ .min_hold_buffer_ns = 4700,
+};
+
+static const struct i2c_spec_values fast_mode_spec = {
+ .min_hold_start_ns = 600,
+ .min_low_ns = 1300,
+ .min_high_ns = 600,
+ .min_setup_start_ns = 600,
+ .max_data_hold_ns = 900,
+ .min_data_setup_ns = 100,
+ .min_setup_stop_ns = 600,
+ .min_hold_buffer_ns = 1300,
+};
+
+static const struct i2c_spec_values fast_mode_plus_spec = {
+ .min_hold_start_ns = 260,
+ .min_low_ns = 500,
+ .min_high_ns = 260,
+ .min_setup_start_ns = 260,
+ .max_data_hold_ns = 400,
+ .min_data_setup_ns = 50,
+ .min_setup_stop_ns = 260,
+ .min_hold_buffer_ns = 500,
+};
+
+/**
+ * struct rk3x_i2c_calced_timings:
+ * @div_low: Divider output for low
+ * @div_high: Divider output for high
+ * @tuning: Used to adjust setup/hold data time,
+ * setup/hold start time and setup stop time for
+ * v1's calc_timings, the tuning should all be 0
+ * for old hardware anyone using v0's calc_timings.
+ */
+struct rk3x_i2c_calced_timings {
+ unsigned long div_low;
+ unsigned long div_high;
+ unsigned int tuning;
+};
+
+enum rk3x_i2c_state {
+ STATE_IDLE,
+ STATE_START,
+ STATE_READ,
+ STATE_WRITE,
+ STATE_STOP
+};
+
+/**
+ * struct rk3x_i2c_soc_data:
+ * @grf_offset: offset inside the grf regmap for setting the i2c type
+ * @calc_timings: Callback function for i2c timing information calculated
+ */
+struct rk3x_i2c_soc_data {
+ int grf_offset;
+ int (*calc_timings)(unsigned long, struct i2c_timings *,
+ struct rk3x_i2c_calced_timings *);
+};
+
+/**
+ * struct rk3x_i2c - private data of the controller
+ * @adap: corresponding I2C adapter
+ * @dev: device for this controller
+ * @soc_data: related soc data struct
+ * @regs: virtual memory area
+ * @clk: function clk for rk3399 or function & Bus clks for others
+ * @pclk: Bus clk for rk3399
+ * @clk_rate_nb: i2c clk rate change notify
+ * @t: I2C known timing information
+ * @lock: spinlock for the i2c bus
+ * @wait: the waitqueue to wait for i2c transfer
+ * @busy: the condition for the event to wait for
+ * @msg: current i2c message
+ * @addr: addr of i2c slave device
+ * @mode: mode of i2c transfer
+ * @is_last_msg: flag determines whether it is the last msg in this transfer
+ * @state: state of i2c transfer
+ * @processed: byte length which has been send or received
+ * @error: error code for i2c transfer
+ */
+struct rk3x_i2c {
+ struct i2c_adapter adap;
+ struct device *dev;
+ const struct rk3x_i2c_soc_data *soc_data;
+
+ /* Hardware resources */
+ void __iomem *regs;
+ struct clk *clk;
+ struct clk *pclk;
+ struct notifier_block clk_rate_nb;
+
+ /* Settings */
+ struct i2c_timings t;
+
+ /* Synchronization & notification */
+ spinlock_t lock;
+ wait_queue_head_t wait;
+ bool busy;
+
+ /* Current message */
+ struct i2c_msg *msg;
+ u8 addr;
+ unsigned int mode;
+ bool is_last_msg;
+
+ /* I2C state machine */
+ enum rk3x_i2c_state state;
+ unsigned int processed;
+ int error;
+};
+
+static inline void i2c_writel(struct rk3x_i2c *i2c, u32 value,
+ unsigned int offset)
+{
+ writel(value, i2c->regs + offset);
+}
+
+static inline u32 i2c_readl(struct rk3x_i2c *i2c, unsigned int offset)
+{
+ return readl(i2c->regs + offset);
+}
+
+/* Reset all interrupt pending bits */
+static inline void rk3x_i2c_clean_ipd(struct rk3x_i2c *i2c)
+{
+ i2c_writel(i2c, REG_INT_ALL, REG_IPD);
+}
+
+/**
+ * Generate a START condition, which triggers a REG_INT_START interrupt.
+ */
+static void rk3x_i2c_start(struct rk3x_i2c *i2c)
+{
+ u32 val = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK;
+
+ i2c_writel(i2c, REG_INT_START, REG_IEN);
+
+ /* enable adapter with correct mode, send START condition */
+ val |= REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START;
+
+ /* if we want to react to NACK, set ACTACK bit */
+ if (!(i2c->msg->flags & I2C_M_IGNORE_NAK))
+ val |= REG_CON_ACTACK;
+
+ i2c_writel(i2c, val, REG_CON);
+}
+
+/**
+ * Generate a STOP condition, which triggers a REG_INT_STOP interrupt.
+ *
+ * @error: Error code to return in rk3x_i2c_xfer
+ */
+static void rk3x_i2c_stop(struct rk3x_i2c *i2c, int error)
+{
+ unsigned int ctrl;
+
+ i2c->processed = 0;
+ i2c->msg = NULL;
+ i2c->error = error;
+
+ if (i2c->is_last_msg) {
+ /* Enable stop interrupt */
+ i2c_writel(i2c, REG_INT_STOP, REG_IEN);
+
+ i2c->state = STATE_STOP;
+
+ ctrl = i2c_readl(i2c, REG_CON);
+ ctrl |= REG_CON_STOP;
+ i2c_writel(i2c, ctrl, REG_CON);
+ } else {
+ /* Signal rk3x_i2c_xfer to start the next message. */
+ i2c->busy = false;
+ i2c->state = STATE_IDLE;
+
+ /*
+ * The HW is actually not capable of REPEATED START. But we can
+ * get the intended effect by resetting its internal state
+ * and issuing an ordinary START.
+ */
+ ctrl = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK;
+ i2c_writel(i2c, ctrl, REG_CON);
+
+ /* signal that we are finished with the current msg */
+ wake_up(&i2c->wait);
+ }
+}
+
+/**
+ * Setup a read according to i2c->msg
+ */
+static void rk3x_i2c_prepare_read(struct rk3x_i2c *i2c)
+{
+ unsigned int len = i2c->msg->len - i2c->processed;
+ u32 con;
+
+ con = i2c_readl(i2c, REG_CON);
+
+ /*
+ * The hw can read up to 32 bytes at a time. If we need more than one
+ * chunk, send an ACK after the last byte of the current chunk.
+ */
+ if (len > 32) {
+ len = 32;
+ con &= ~REG_CON_LASTACK;
+ } else {
+ con |= REG_CON_LASTACK;
+ }
+
+ /* make sure we are in plain RX mode if we read a second chunk */
+ if (i2c->processed != 0) {
+ con &= ~REG_CON_MOD_MASK;
+ con |= REG_CON_MOD(REG_CON_MOD_RX);
+ }
+
+ i2c_writel(i2c, con, REG_CON);
+ i2c_writel(i2c, len, REG_MRXCNT);
+}
+
+/**
+ * Fill the transmit buffer with data from i2c->msg
+ */
+static void rk3x_i2c_fill_transmit_buf(struct rk3x_i2c *i2c)
+{
+ unsigned int i, j;
+ u32 cnt = 0;
+ u32 val;
+ u8 byte;
+
+ for (i = 0; i < 8; ++i) {
+ val = 0;
+ for (j = 0; j < 4; ++j) {
+ if ((i2c->processed == i2c->msg->len) && (cnt != 0))
+ break;
+
+ if (i2c->processed == 0 && cnt == 0)
+ byte = (i2c->addr & 0x7f) << 1;
+ else
+ byte = i2c->msg->buf[i2c->processed++];
+
+ val |= byte << (j * 8);
+ cnt++;
+ }
+
+ i2c_writel(i2c, val, TXBUFFER_BASE + 4 * i);
+
+ if (i2c->processed == i2c->msg->len)
+ break;
+ }
+
+ i2c_writel(i2c, cnt, REG_MTXCNT);
+}
+
+
+/* IRQ handlers for individual states */
+
+static void rk3x_i2c_handle_start(struct rk3x_i2c *i2c, unsigned int ipd)
+{
+ if (!(ipd & REG_INT_START)) {
+ rk3x_i2c_stop(i2c, -EIO);
+ dev_warn(i2c->dev, "unexpected irq in START: 0x%x\n", ipd);
+ rk3x_i2c_clean_ipd(i2c);
+ return;
+ }
+
+ /* ack interrupt */
+ i2c_writel(i2c, REG_INT_START, REG_IPD);
+
+ /* disable start bit */
+ i2c_writel(i2c, i2c_readl(i2c, REG_CON) & ~REG_CON_START, REG_CON);
+
+ /* enable appropriate interrupts and transition */
+ if (i2c->mode == REG_CON_MOD_TX) {
+ i2c_writel(i2c, REG_INT_MBTF | REG_INT_NAKRCV, REG_IEN);
+ i2c->state = STATE_WRITE;
+ rk3x_i2c_fill_transmit_buf(i2c);
+ } else {
+ /* in any other case, we are going to be reading. */
+ i2c_writel(i2c, REG_INT_MBRF | REG_INT_NAKRCV, REG_IEN);
+ i2c->state = STATE_READ;
+ rk3x_i2c_prepare_read(i2c);
+ }
+}
+
+static void rk3x_i2c_handle_write(struct rk3x_i2c *i2c, unsigned int ipd)
+{
+ if (!(ipd & REG_INT_MBTF)) {
+ rk3x_i2c_stop(i2c, -EIO);
+ dev_err(i2c->dev, "unexpected irq in WRITE: 0x%x\n", ipd);
+ rk3x_i2c_clean_ipd(i2c);
+ return;
+ }
+
+ /* ack interrupt */
+ i2c_writel(i2c, REG_INT_MBTF, REG_IPD);
+
+ /* are we finished? */
+ if (i2c->processed == i2c->msg->len)
+ rk3x_i2c_stop(i2c, i2c->error);
+ else
+ rk3x_i2c_fill_transmit_buf(i2c);
+}
+
+static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd)
+{
+ unsigned int i;
+ unsigned int len = i2c->msg->len - i2c->processed;
+ u32 uninitialized_var(val);
+ u8 byte;
+
+ /* we only care for MBRF here. */
+ if (!(ipd & REG_INT_MBRF))
+ return;
+
+ /* ack interrupt (read also produces a spurious START flag, clear it too) */
+ i2c_writel(i2c, REG_INT_MBRF | REG_INT_START, REG_IPD);
+
+ /* Can only handle a maximum of 32 bytes at a time */
+ if (len > 32)
+ len = 32;
+
+ /* read the data from receive buffer */
+ for (i = 0; i < len; ++i) {
+ if (i % 4 == 0)
+ val = i2c_readl(i2c, RXBUFFER_BASE + (i / 4) * 4);
+
+ byte = (val >> ((i % 4) * 8)) & 0xff;
+ i2c->msg->buf[i2c->processed++] = byte;
+ }
+
+ /* are we finished? */
+ if (i2c->processed == i2c->msg->len)
+ rk3x_i2c_stop(i2c, i2c->error);
+ else
+ rk3x_i2c_prepare_read(i2c);
+}
+
+static void rk3x_i2c_handle_stop(struct rk3x_i2c *i2c, unsigned int ipd)
+{
+ unsigned int con;
+
+ if (!(ipd & REG_INT_STOP)) {
+ rk3x_i2c_stop(i2c, -EIO);
+ dev_err(i2c->dev, "unexpected irq in STOP: 0x%x\n", ipd);
+ rk3x_i2c_clean_ipd(i2c);
+ return;
+ }
+
+ /* ack interrupt */
+ i2c_writel(i2c, REG_INT_STOP, REG_IPD);
+
+ /* disable STOP bit */
+ con = i2c_readl(i2c, REG_CON);
+ con &= ~REG_CON_STOP;
+ i2c_writel(i2c, con, REG_CON);
+
+ i2c->busy = false;
+ i2c->state = STATE_IDLE;
+
+ /* signal rk3x_i2c_xfer that we are finished */
+ wake_up(&i2c->wait);
+}
+
+static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id)
+{
+ struct rk3x_i2c *i2c = dev_id;
+ unsigned int ipd;
+
+ spin_lock(&i2c->lock);
+
+ ipd = i2c_readl(i2c, REG_IPD);
+ if (i2c->state == STATE_IDLE) {
+ dev_warn(i2c->dev, "irq in STATE_IDLE, ipd = 0x%x\n", ipd);
+ rk3x_i2c_clean_ipd(i2c);
+ goto out;
+ }
+
+ dev_dbg(i2c->dev, "IRQ: state %d, ipd: %x\n", i2c->state, ipd);
+
+ /* Clean interrupt bits we don't care about */
+ ipd &= ~(REG_INT_BRF | REG_INT_BTF);
+
+ if (ipd & REG_INT_NAKRCV) {
+ /*
+ * We got a NACK in the last operation. Depending on whether
+ * IGNORE_NAK is set, we have to stop the operation and report
+ * an error.
+ */
+ i2c_writel(i2c, REG_INT_NAKRCV, REG_IPD);
+
+ ipd &= ~REG_INT_NAKRCV;
+
+ if (!(i2c->msg->flags & I2C_M_IGNORE_NAK))
+ rk3x_i2c_stop(i2c, -ENXIO);
+ }
+
+ /* is there anything left to handle? */
+ if ((ipd & REG_INT_ALL) == 0)
+ goto out;
+
+ switch (i2c->state) {
+ case STATE_START:
+ rk3x_i2c_handle_start(i2c, ipd);
+ break;
+ case STATE_WRITE:
+ rk3x_i2c_handle_write(i2c, ipd);
+ break;
+ case STATE_READ:
+ rk3x_i2c_handle_read(i2c, ipd);
+ break;
+ case STATE_STOP:
+ rk3x_i2c_handle_stop(i2c, ipd);
+ break;
+ case STATE_IDLE:
+ break;
+ }
+
+out:
+ spin_unlock(&i2c->lock);
+ return IRQ_HANDLED;
+}
+
+/**
+ * Get timing values of I2C specification
+ *
+ * @speed: Desired SCL frequency
+ *
+ * Returns: Matched i2c spec values.
+ */
+static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed)
+{
+ if (speed <= 100000)
+ return &standard_mode_spec;
+ else if (speed <= 400000)
+ return &fast_mode_spec;
+ else
+ return &fast_mode_plus_spec;
+}
+
+/**
+ * Calculate divider values for desired SCL frequency
+ *
+ * @clk_rate: I2C input clock rate
+ * @t: Known I2C timing information
+ * @t_calc: Caculated rk3x private timings that would be written into regs
+ *
+ * Returns: 0 on success, -EINVAL if the goal SCL rate is too slow. In that case
+ * a best-effort divider value is returned in divs. If the target rate is
+ * too high, we silently use the highest possible rate.
+ */
+static int rk3x_i2c_v0_calc_timings(unsigned long clk_rate,
+ struct i2c_timings *t,
+ struct rk3x_i2c_calced_timings *t_calc)
+{
+ unsigned long min_low_ns, min_high_ns;
+ unsigned long max_low_ns, min_total_ns;
+
+ unsigned long clk_rate_khz, scl_rate_khz;
+
+ unsigned long min_low_div, min_high_div;
+ unsigned long max_low_div;
+
+ unsigned long min_div_for_hold, min_total_div;
+ unsigned long extra_div, extra_low_div, ideal_low_div;
+
+ unsigned long data_hold_buffer_ns = 50;
+ const struct i2c_spec_values *spec;
+ int ret = 0;
+
+ /* Only support standard-mode and fast-mode */
+ if (WARN_ON(t->bus_freq_hz > 400000))
+ t->bus_freq_hz = 400000;
+
+ /* prevent scl_rate_khz from becoming 0 */
+ if (WARN_ON(t->bus_freq_hz < 1000))
+ t->bus_freq_hz = 1000;
+
+ /*
+ * min_low_ns: The minimum number of ns we need to hold low to
+ * meet I2C specification, should include fall time.
+ * min_high_ns: The minimum number of ns we need to hold high to
+ * meet I2C specification, should include rise time.
+ * max_low_ns: The maximum number of ns we can hold low to meet
+ * I2C specification.
+ *
+ * Note: max_low_ns should be (maximum data hold time * 2 - buffer)
+ * This is because the i2c host on Rockchip holds the data line
+ * for half the low time.
+ */
+ spec = rk3x_i2c_get_spec(t->bus_freq_hz);
+ min_high_ns = t->scl_rise_ns + spec->min_high_ns;
+
+ /*
+ * Timings for repeated start:
+ * - controller appears to drop SDA at .875x (7/8) programmed clk high.
+ * - controller appears to keep SCL high for 2x programmed clk high.
+ *
+ * We need to account for those rules in picking our "high" time so
+ * we meet tSU;STA and tHD;STA times.
+ */
+ min_high_ns = max(min_high_ns, DIV_ROUND_UP(
+ (t->scl_rise_ns + spec->min_setup_start_ns) * 1000, 875));
+ min_high_ns = max(min_high_ns, DIV_ROUND_UP(
+ (t->scl_rise_ns + spec->min_setup_start_ns + t->sda_fall_ns +
+ spec->min_high_ns), 2));
+
+ min_low_ns = t->scl_fall_ns + spec->min_low_ns;
+ max_low_ns = spec->max_data_hold_ns * 2 - data_hold_buffer_ns;
+ min_total_ns = min_low_ns + min_high_ns;
+
+ /* Adjust to avoid overflow */
+ clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000);
+ scl_rate_khz = t->bus_freq_hz / 1000;
+
+ /*
+ * We need the total div to be >= this number
+ * so we don't clock too fast.
+ */
+ min_total_div = DIV_ROUND_UP(clk_rate_khz, scl_rate_khz * 8);
+
+ /* These are the min dividers needed for min hold times. */
+ min_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns, 8 * 1000000);
+ min_high_div = DIV_ROUND_UP(clk_rate_khz * min_high_ns, 8 * 1000000);
+ min_div_for_hold = (min_low_div + min_high_div);
+
+ /*
+ * This is the maximum divider so we don't go over the maximum.
+ * We don't round up here (we round down) since this is a maximum.
+ */
+ max_low_div = clk_rate_khz * max_low_ns / (8 * 1000000);
+
+ if (min_low_div > max_low_div) {
+ WARN_ONCE(true,
+ "Conflicting, min_low_div %lu, max_low_div %lu\n",
+ min_low_div, max_low_div);
+ max_low_div = min_low_div;
+ }
+
+ if (min_div_for_hold > min_total_div) {
+ /*
+ * Time needed to meet hold requirements is important.
+ * Just use that.
+ */
+ t_calc->div_low = min_low_div;
+ t_calc->div_high = min_high_div;
+ } else {
+ /*
+ * We've got to distribute some time among the low and high
+ * so we don't run too fast.
+ */
+ extra_div = min_total_div - min_div_for_hold;
+
+ /*
+ * We'll try to split things up perfectly evenly,
+ * biasing slightly towards having a higher div
+ * for low (spend more time low).
+ */
+ ideal_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns,
+ scl_rate_khz * 8 * min_total_ns);
+
+ /* Don't allow it to go over the maximum */
+ if (ideal_low_div > max_low_div)
+ ideal_low_div = max_low_div;
+
+ /*
+ * Handle when the ideal low div is going to take up
+ * more than we have.
+ */
+ if (ideal_low_div > min_low_div + extra_div)
+ ideal_low_div = min_low_div + extra_div;
+
+ /* Give low the "ideal" and give high whatever extra is left */
+ extra_low_div = ideal_low_div - min_low_div;
+ t_calc->div_low = ideal_low_div;
+ t_calc->div_high = min_high_div + (extra_div - extra_low_div);
+ }
+
+ /*
+ * Adjust to the fact that the hardware has an implicit "+1".
+ * NOTE: Above calculations always produce div_low > 0 and div_high > 0.
+ */
+ t_calc->div_low--;
+ t_calc->div_high--;
+
+ /* Give the tuning value 0, that would not update con register */
+ t_calc->tuning = 0;
+ /* Maximum divider supported by hw is 0xffff */
+ if (t_calc->div_low > 0xffff) {
+ t_calc->div_low = 0xffff;
+ ret = -EINVAL;
+ }
+
+ if (t_calc->div_high > 0xffff) {
+ t_calc->div_high = 0xffff;
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+/**
+ * Calculate timing values for desired SCL frequency
+ *
+ * @clk_rate: I2C input clock rate
+ * @t: Known I2C timing information
+ * @t_calc: Caculated rk3x private timings that would be written into regs
+ *
+ * Returns: 0 on success, -EINVAL if the goal SCL rate is too slow. In that case
+ * a best-effort divider value is returned in divs. If the target rate is
+ * too high, we silently use the highest possible rate.
+ * The following formulas are v1's method to calculate timings.
+ *
+ * l = divl + 1;
+ * h = divh + 1;
+ * s = sda_update_config + 1;
+ * u = start_setup_config + 1;
+ * p = stop_setup_config + 1;
+ * T = Tclk_i2c;
+ *
+ * tHigh = 8 * h * T;
+ * tLow = 8 * l * T;
+ *
+ * tHD;sda = (l * s + 1) * T;
+ * tSU;sda = [(8 - s) * l + 1] * T;
+ * tI2C = 8 * (l + h) * T;
+ *
+ * tSU;sta = (8h * u + 1) * T;
+ * tHD;sta = [8h * (u + 1) - 1] * T;
+ * tSU;sto = (8h * p + 1) * T;
+ */
+static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate,
+ struct i2c_timings *t,
+ struct rk3x_i2c_calced_timings *t_calc)
+{
+ unsigned long min_low_ns, min_high_ns;
+ unsigned long min_setup_start_ns, min_setup_data_ns;
+ unsigned long min_setup_stop_ns, max_hold_data_ns;
+
+ unsigned long clk_rate_khz, scl_rate_khz;
+
+ unsigned long min_low_div, min_high_div;
+
+ unsigned long min_div_for_hold, min_total_div;
+ unsigned long extra_div, extra_low_div;
+ unsigned long sda_update_cfg, stp_sta_cfg, stp_sto_cfg;
+
+ const struct i2c_spec_values *spec;
+ int ret = 0;
+
+ /* Support standard-mode, fast-mode and fast-mode plus */
+ if (WARN_ON(t->bus_freq_hz > 1000000))
+ t->bus_freq_hz = 1000000;
+
+ /* prevent scl_rate_khz from becoming 0 */
+ if (WARN_ON(t->bus_freq_hz < 1000))
+ t->bus_freq_hz = 1000;
+
+ /*
+ * min_low_ns: The minimum number of ns we need to hold low to
+ * meet I2C specification, should include fall time.
+ * min_high_ns: The minimum number of ns we need to hold high to
+ * meet I2C specification, should include rise time.
+ */
+ spec = rk3x_i2c_get_spec(t->bus_freq_hz);
+
+ /* calculate min-divh and min-divl */
+ clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000);
+ scl_rate_khz = t->bus_freq_hz / 1000;
+ min_total_div = DIV_ROUND_UP(clk_rate_khz, scl_rate_khz * 8);
+
+ min_high_ns = t->scl_rise_ns + spec->min_high_ns;
+ min_high_div = DIV_ROUND_UP(clk_rate_khz * min_high_ns, 8 * 1000000);
+
+ min_low_ns = t->scl_fall_ns + spec->min_low_ns;
+ min_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns, 8 * 1000000);
+
+ /*
+ * Final divh and divl must be greater than 0, otherwise the
+ * hardware would not output the i2c clk.
+ */
+ min_high_div = (min_high_div < 1) ? 2 : min_high_div;
+ min_low_div = (min_low_div < 1) ? 2 : min_low_div;
+
+ /* These are the min dividers needed for min hold times. */
+ min_div_for_hold = (min_low_div + min_high_div);
+
+ /*
+ * This is the maximum divider so we don't go over the maximum.
+ * We don't round up here (we round down) since this is a maximum.
+ */
+ if (min_div_for_hold >= min_total_div) {
+ /*
+ * Time needed to meet hold requirements is important.
+ * Just use that.
+ */
+ t_calc->div_low = min_low_div;
+ t_calc->div_high = min_high_div;
+ } else {
+ /*
+ * We've got to distribute some time among the low and high
+ * so we don't run too fast.
+ * We'll try to split things up by the scale of min_low_div and
+ * min_high_div, biasing slightly towards having a higher div
+ * for low (spend more time low).
+ */
+ extra_div = min_total_div - min_div_for_hold;
+ extra_low_div = DIV_ROUND_UP(min_low_div * extra_div,
+ min_div_for_hold);
+
+ t_calc->div_low = min_low_div + extra_low_div;
+ t_calc->div_high = min_high_div + (extra_div - extra_low_div);
+ }
+
+ /*
+ * calculate sda data hold count by the rules, data_upd_st:3
+ * is a appropriate value to reduce calculated times.
+ */
+ for (sda_update_cfg = 3; sda_update_cfg > 0; sda_update_cfg--) {
+ max_hold_data_ns = DIV_ROUND_UP((sda_update_cfg
+ * (t_calc->div_low) + 1)
+ * 1000000, clk_rate_khz);
+ min_setup_data_ns = DIV_ROUND_UP(((8 - sda_update_cfg)
+ * (t_calc->div_low) + 1)
+ * 1000000, clk_rate_khz);
+ if ((max_hold_data_ns < spec->max_data_hold_ns) &&
+ (min_setup_data_ns > spec->min_data_setup_ns))
+ break;
+ }
+
+ /* calculate setup start config */
+ min_setup_start_ns = t->scl_rise_ns + spec->min_setup_start_ns;
+ stp_sta_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_start_ns
+ - 1000000, 8 * 1000000 * (t_calc->div_high));
+
+ /* calculate setup stop config */
+ min_setup_stop_ns = t->scl_rise_ns + spec->min_setup_stop_ns;
+ stp_sto_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_stop_ns
+ - 1000000, 8 * 1000000 * (t_calc->div_high));
+
+ t_calc->tuning = REG_CON_SDA_CFG(--sda_update_cfg) |
+ REG_CON_STA_CFG(--stp_sta_cfg) |
+ REG_CON_STO_CFG(--stp_sto_cfg);
+
+ t_calc->div_low--;
+ t_calc->div_high--;
+
+ /* Maximum divider supported by hw is 0xffff */
+ if (t_calc->div_low > 0xffff) {
+ t_calc->div_low = 0xffff;
+ ret = -EINVAL;
+ }
+
+ if (t_calc->div_high > 0xffff) {
+ t_calc->div_high = 0xffff;
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
+{
+ struct i2c_timings *t = &i2c->t;
+ struct rk3x_i2c_calced_timings calc;
+ u64 t_low_ns, t_high_ns;
+ unsigned long flags;
+ u32 val;
+ int ret;
+
+ ret = i2c->soc_data->calc_timings(clk_rate, t, &calc);
+ WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz);
+
+ clk_enable(i2c->pclk);
+
+ spin_lock_irqsave(&i2c->lock, flags);
+ val = i2c_readl(i2c, REG_CON);
+ val &= ~REG_CON_TUNING_MASK;
+ val |= calc.tuning;
+ i2c_writel(i2c, val, REG_CON);
+ i2c_writel(i2c, (calc.div_high << 16) | (calc.div_low & 0xffff),
+ REG_CLKDIV);
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ clk_disable(i2c->pclk);
+
+ t_low_ns = div_u64(((u64)calc.div_low + 1) * 8 * 1000000000, clk_rate);
+ t_high_ns = div_u64(((u64)calc.div_high + 1) * 8 * 1000000000,
+ clk_rate);
+ dev_dbg(i2c->dev,
+ "CLK %lukhz, Req %uns, Act low %lluns high %lluns\n",
+ clk_rate / 1000,
+ 1000000000 / t->bus_freq_hz,
+ t_low_ns, t_high_ns);
+}
+
+/**
+ * rk3x_i2c_clk_notifier_cb - Clock rate change callback
+ * @nb: Pointer to notifier block
+ * @event: Notification reason
+ * @data: Pointer to notification data object
+ *
+ * The callback checks whether a valid bus frequency can be generated after the
+ * change. If so, the change is acknowledged, otherwise the change is aborted.
+ * New dividers are written to the HW in the pre- or post change notification
+ * depending on the scaling direction.
+ *
+ * Code adapted from i2c-cadence.c.
+ *
+ * Return: NOTIFY_STOP if the rate change should be aborted, NOTIFY_OK
+ * to acknowledge the change, NOTIFY_DONE if the notification is
+ * considered irrelevant.
+ */
+static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
+ event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct rk3x_i2c *i2c = container_of(nb, struct rk3x_i2c, clk_rate_nb);
+ struct rk3x_i2c_calced_timings calc;
+
+ switch (event) {
+ case PRE_RATE_CHANGE:
+ /*
+ * Try the calculation (but don't store the result) ahead of
+ * time to see if we need to block the clock change. Timings
+ * shouldn't actually take effect until rk3x_i2c_adapt_div().
+ */
+ if (i2c->soc_data->calc_timings(ndata->new_rate, &i2c->t,
+ &calc) != 0)
+ return NOTIFY_STOP;
+
+ /* scale up */
+ if (ndata->new_rate > ndata->old_rate)
+ rk3x_i2c_adapt_div(i2c, ndata->new_rate);
+
+ return NOTIFY_OK;
+ case POST_RATE_CHANGE:
+ /* scale down */
+ if (ndata->new_rate < ndata->old_rate)
+ rk3x_i2c_adapt_div(i2c, ndata->new_rate);
+ return NOTIFY_OK;
+ case ABORT_RATE_CHANGE:
+ /* scale up */
+ if (ndata->new_rate > ndata->old_rate)
+ rk3x_i2c_adapt_div(i2c, ndata->old_rate);
+ return NOTIFY_OK;
+ default:
+ return NOTIFY_DONE;
+ }
+}
+
+/**
+ * Setup I2C registers for an I2C operation specified by msgs, num.
+ *
+ * Must be called with i2c->lock held.
+ *
+ * @msgs: I2C msgs to process
+ * @num: Number of msgs
+ *
+ * returns: Number of I2C msgs processed or negative in case of error
+ */
+static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, int num)
+{
+ u32 addr = (msgs[0].addr & 0x7f) << 1;
+ int ret = 0;
+
+ /*
+ * The I2C adapter can issue a small (len < 4) write packet before
+ * reading. This speeds up SMBus-style register reads.
+ * The MRXADDR/MRXRADDR hold the slave address and the slave register
+ * address in this case.
+ */
+
+ if (num >= 2 && msgs[0].len < 4 &&
+ !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
+ u32 reg_addr = 0;
+ int i;
+
+ dev_dbg(i2c->dev, "Combined write/read from addr 0x%x\n",
+ addr >> 1);
+
+ /* Fill MRXRADDR with the register address(es) */
+ for (i = 0; i < msgs[0].len; ++i) {
+ reg_addr |= msgs[0].buf[i] << (i * 8);
+ reg_addr |= REG_MRXADDR_VALID(i);
+ }
+
+ /* msgs[0] is handled by hw. */
+ i2c->msg = &msgs[1];
+
+ i2c->mode = REG_CON_MOD_REGISTER_TX;
+
+ i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), REG_MRXADDR);
+ i2c_writel(i2c, reg_addr, REG_MRXRADDR);
+
+ ret = 2;
+ } else {
+ /*
+ * We'll have to do it the boring way and process the msgs
+ * one-by-one.
+ */
+
+ if (msgs[0].flags & I2C_M_RD) {
+ addr |= 1; /* set read bit */
+
+ /*
+ * We have to transmit the slave addr first. Use
+ * MOD_REGISTER_TX for that purpose.
+ */
+ i2c->mode = REG_CON_MOD_REGISTER_TX;
+ i2c_writel(i2c, addr | REG_MRXADDR_VALID(0),
+ REG_MRXADDR);
+ i2c_writel(i2c, 0, REG_MRXRADDR);
+ } else {
+ i2c->mode = REG_CON_MOD_TX;
+ }
+
+ i2c->msg = &msgs[0];
+
+ ret = 1;
+ }
+
+ i2c->addr = msgs[0].addr;
+ i2c->busy = true;
+ i2c->state = STATE_START;
+ i2c->processed = 0;
+ i2c->error = 0;
+
+ rk3x_i2c_clean_ipd(i2c);
+
+ return ret;
+}
+
+static int rk3x_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data;
+ unsigned long timeout, flags;
+ u32 val;
+ int ret = 0;
+ int i;
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ clk_enable(i2c->clk);
+ clk_enable(i2c->pclk);
+
+ i2c->is_last_msg = false;
+
+ /*
+ * Process msgs. We can handle more than one message at once (see
+ * rk3x_i2c_setup()).
+ */
+ for (i = 0; i < num; i += ret) {
+ ret = rk3x_i2c_setup(i2c, msgs + i, num - i);
+
+ if (ret < 0) {
+ dev_err(i2c->dev, "rk3x_i2c_setup() failed\n");
+ break;
+ }
+
+ if (i + ret >= num)
+ i2c->is_last_msg = true;
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ rk3x_i2c_start(i2c);
+
+ timeout = wait_event_timeout(i2c->wait, !i2c->busy,
+ msecs_to_jiffies(WAIT_TIMEOUT));
+
+ spin_lock_irqsave(&i2c->lock, flags);
+
+ if (timeout == 0) {
+ dev_err(i2c->dev, "timeout, ipd: 0x%02x, state: %d\n",
+ i2c_readl(i2c, REG_IPD), i2c->state);
+
+ /* Force a STOP condition without interrupt */
+ i2c_writel(i2c, 0, REG_IEN);
+ val = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK;
+ val |= REG_CON_EN | REG_CON_STOP;
+ i2c_writel(i2c, val, REG_CON);
+
+ i2c->state = STATE_IDLE;
+
+ ret = -ETIMEDOUT;
+ break;
+ }
+
+ if (i2c->error) {
+ ret = i2c->error;
+ break;
+ }
+ }
+
+ clk_disable(i2c->pclk);
+ clk_disable(i2c->clk);
+
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ return ret < 0 ? ret : num;
+}
+
+static __maybe_unused int rk3x_i2c_resume(struct device *dev)
+{
+ struct rk3x_i2c *i2c = dev_get_drvdata(dev);
+
+ rk3x_i2c_adapt_div(i2c, clk_get_rate(i2c->clk));
+
+ return 0;
+}
+
+static u32 rk3x_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static const struct i2c_algorithm rk3x_i2c_algorithm = {
+ .master_xfer = rk3x_i2c_xfer,
+ .functionality = rk3x_i2c_func,
+};
+
+static const struct rk3x_i2c_soc_data rv1108_soc_data = {
+ .grf_offset = -1,
+ .calc_timings = rk3x_i2c_v1_calc_timings,
+};
+
+static const struct rk3x_i2c_soc_data rk3066_soc_data = {
+ .grf_offset = 0x154,
+ .calc_timings = rk3x_i2c_v0_calc_timings,
+};
+
+static const struct rk3x_i2c_soc_data rk3188_soc_data = {
+ .grf_offset = 0x0a4,
+ .calc_timings = rk3x_i2c_v0_calc_timings,
+};
+
+static const struct rk3x_i2c_soc_data rk3228_soc_data = {
+ .grf_offset = -1,
+ .calc_timings = rk3x_i2c_v0_calc_timings,
+};
+
+static const struct rk3x_i2c_soc_data rk3288_soc_data = {
+ .grf_offset = -1,
+ .calc_timings = rk3x_i2c_v0_calc_timings,
+};
+
+static const struct rk3x_i2c_soc_data rk3399_soc_data = {
+ .grf_offset = -1,
+ .calc_timings = rk3x_i2c_v1_calc_timings,
+};
+
+static const struct of_device_id rk3x_i2c_match[] = {
+ {
+ .compatible = "rockchip,rv1108-i2c",
+ .data = &rv1108_soc_data
+ },
+ {
+ .compatible = "rockchip,rk3066-i2c",
+ .data = &rk3066_soc_data
+ },
+ {
+ .compatible = "rockchip,rk3188-i2c",
+ .data = &rk3188_soc_data
+ },
+ {
+ .compatible = "rockchip,rk3228-i2c",
+ .data = &rk3228_soc_data
+ },
+ {
+ .compatible = "rockchip,rk3288-i2c",
+ .data = &rk3288_soc_data
+ },
+ {
+ .compatible = "rockchip,rk3399-i2c",
+ .data = &rk3399_soc_data
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rk3x_i2c_match);
+
+static int rk3x_i2c_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ const struct of_device_id *match;
+ struct rk3x_i2c *i2c;
+ struct resource *mem;
+ int ret = 0;
+ int bus_nr;
+ u32 value;
+ int irq;
+ unsigned long clk_rate;
+
+ i2c = devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ match = of_match_node(rk3x_i2c_match, np);
+ i2c->soc_data = match->data;
+
+ /* use common interface to get I2C timing properties */
+ i2c_parse_fw_timings(&pdev->dev, &i2c->t, true);
+
+ strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name));
+ i2c->adap.owner = THIS_MODULE;
+ i2c->adap.algo = &rk3x_i2c_algorithm;
+ i2c->adap.retries = 3;
+ i2c->adap.dev.of_node = np;
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = &pdev->dev;
+
+ i2c->dev = &pdev->dev;
+
+ spin_lock_init(&i2c->lock);
+ init_waitqueue_head(&i2c->wait);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(i2c->regs))
+ return PTR_ERR(i2c->regs);
+
+ /* Try to set the I2C adapter number from dt */
+ bus_nr = of_alias_get_id(np, "i2c");
+
+ /*
+ * Switch to new interface if the SoC also offers the old one.
+ * The control bit is located in the GRF register space.
+ */
+ if (i2c->soc_data->grf_offset >= 0) {
+ struct regmap *grf;
+
+ grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
+ if (IS_ERR(grf)) {
+ dev_err(&pdev->dev,
+ "rk3x-i2c needs 'rockchip,grf' property\n");
+ return PTR_ERR(grf);
+ }
+
+ if (bus_nr < 0) {
+ dev_err(&pdev->dev, "rk3x-i2c needs i2cX alias");
+ return -EINVAL;
+ }
+
+ /* 27+i: write mask, 11+i: value */
+ value = BIT(27 + bus_nr) | BIT(11 + bus_nr);
+
+ ret = regmap_write(grf, i2c->soc_data->grf_offset, value);
+ if (ret != 0) {
+ dev_err(i2c->dev, "Could not write to GRF: %d\n", ret);
+ return ret;
+ }
+ }
+
+ /* IRQ setup */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "cannot find rk3x IRQ\n");
+ return irq;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, rk3x_i2c_irq,
+ 0, dev_name(&pdev->dev), i2c);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cannot request IRQ\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, i2c);
+
+ if (i2c->soc_data->calc_timings == rk3x_i2c_v0_calc_timings) {
+ /* Only one clock to use for bus clock and peripheral clock */
+ i2c->clk = devm_clk_get(&pdev->dev, NULL);
+ i2c->pclk = i2c->clk;
+ } else {
+ i2c->clk = devm_clk_get(&pdev->dev, "i2c");
+ i2c->pclk = devm_clk_get(&pdev->dev, "pclk");
+ }
+
+ if (IS_ERR(i2c->clk)) {
+ ret = PTR_ERR(i2c->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Can't get bus clk: %d\n", ret);
+ return ret;
+ }
+ if (IS_ERR(i2c->pclk)) {
+ ret = PTR_ERR(i2c->pclk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Can't get periph clk: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare(i2c->clk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Can't prepare bus clk: %d\n", ret);
+ return ret;
+ }
+ ret = clk_prepare(i2c->pclk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Can't prepare periph clock: %d\n", ret);
+ goto err_clk;
+ }
+
+ i2c->clk_rate_nb.notifier_call = rk3x_i2c_clk_notifier_cb;
+ ret = clk_notifier_register(i2c->clk, &i2c->clk_rate_nb);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "Unable to register clock notifier\n");
+ goto err_pclk;
+ }
+
+ clk_rate = clk_get_rate(i2c->clk);
+ rk3x_i2c_adapt_div(i2c, clk_rate);
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret < 0)
+ goto err_clk_notifier;
+
+ return 0;
+
+err_clk_notifier:
+ clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb);
+err_pclk:
+ clk_unprepare(i2c->pclk);
+err_clk:
+ clk_unprepare(i2c->clk);
+ return ret;
+}
+
+static int rk3x_i2c_remove(struct platform_device *pdev)
+{
+ struct rk3x_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adap);
+
+ clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb);
+ clk_unprepare(i2c->pclk);
+ clk_unprepare(i2c->clk);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rk3x_i2c_pm_ops, NULL, rk3x_i2c_resume);
+
+static struct platform_driver rk3x_i2c_driver = {
+ .probe = rk3x_i2c_probe,
+ .remove = rk3x_i2c_remove,
+ .driver = {
+ .name = "rk3x-i2c",
+ .of_match_table = rk3x_i2c_match,
+ .pm = &rk3x_i2c_pm_ops,
+ },
+};
+
+module_platform_driver(rk3x_i2c_driver);
+
+MODULE_DESCRIPTION("Rockchip RK3xxx I2C Bus driver");
+MODULE_AUTHOR("Max Schwarz <max.schwarz@online.de>");
+MODULE_LICENSE("GPL v2");