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i2c: sh_mobile: implement atomic transfers
Implements atomic transfers to fix reboot/shutdown on r8a7790 Lager and similar boards. Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> [wsa: some whitespace fixing] Signed-off-by: Wolfram Sang <wsa@kernel.org>
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aafced673c
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a49cc1fe9d
1 changed files with 65 additions and 19 deletions
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@ -129,6 +129,7 @@ struct sh_mobile_i2c_data {
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int sr;
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bool send_stop;
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bool stop_after_dma;
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bool atomic_xfer;
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struct resource *res;
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struct dma_chan *dma_tx;
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@ -330,13 +331,15 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, enum sh_mobile_i2c_op
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ret = iic_rd(pd, ICDR);
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break;
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case OP_RX_STOP: /* enable DTE interrupt, issue stop */
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iic_wr(pd, ICIC,
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ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
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if (!pd->atomic_xfer)
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iic_wr(pd, ICIC,
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ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
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iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
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break;
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case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
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iic_wr(pd, ICIC,
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ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
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if (!pd->atomic_xfer)
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iic_wr(pd, ICIC,
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ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
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ret = iic_rd(pd, ICDR);
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iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
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break;
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@ -429,7 +432,8 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
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if (wakeup) {
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pd->sr |= SW_DONE;
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wake_up(&pd->wait);
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if (!pd->atomic_xfer)
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wake_up(&pd->wait);
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}
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/* defeat write posting to avoid spurious WAIT interrupts */
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@ -581,6 +585,9 @@ static void start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
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pd->pos = -1;
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pd->sr = 0;
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if (pd->atomic_xfer)
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return;
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pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
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if (pd->dma_buf)
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sh_mobile_i2c_xfer_dma(pd);
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@ -637,15 +644,13 @@ static int poll_busy(struct sh_mobile_i2c_data *pd)
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return i ? 0 : -ETIMEDOUT;
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}
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static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
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struct i2c_msg *msgs,
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int num)
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static int sh_mobile_xfer(struct sh_mobile_i2c_data *pd,
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struct i2c_msg *msgs, int num)
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{
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struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
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struct i2c_msg *msg;
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int err = 0;
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int i;
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long timeout;
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long time_left;
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/* Wake up device and enable clock */
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pm_runtime_get_sync(pd->dev);
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@ -662,15 +667,35 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
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if (do_start)
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i2c_op(pd, OP_START);
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/* The interrupt handler takes care of the rest... */
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timeout = wait_event_timeout(pd->wait,
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pd->sr & (ICSR_TACK | SW_DONE),
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adapter->timeout);
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if (pd->atomic_xfer) {
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unsigned long j = jiffies + pd->adap.timeout;
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/* 'stop_after_dma' tells if DMA transfer was complete */
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i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg, pd->stop_after_dma);
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time_left = time_before_eq(jiffies, j);
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while (time_left &&
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!(pd->sr & (ICSR_TACK | SW_DONE))) {
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unsigned char sr = iic_rd(pd, ICSR);
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if (!timeout) {
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if (sr & (ICSR_AL | ICSR_TACK |
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ICSR_WAIT | ICSR_DTE)) {
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sh_mobile_i2c_isr(0, pd);
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udelay(150);
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} else {
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cpu_relax();
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}
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time_left = time_before_eq(jiffies, j);
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}
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} else {
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/* The interrupt handler takes care of the rest... */
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time_left = wait_event_timeout(pd->wait,
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pd->sr & (ICSR_TACK | SW_DONE),
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pd->adap.timeout);
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/* 'stop_after_dma' tells if DMA xfer was complete */
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i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg,
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pd->stop_after_dma);
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}
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if (!time_left) {
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dev_err(pd->dev, "Transfer request timed out\n");
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if (pd->dma_direction != DMA_NONE)
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sh_mobile_i2c_cleanup_dma(pd);
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@ -696,14 +721,35 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
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return err ?: num;
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}
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static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
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struct i2c_msg *msgs,
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int num)
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{
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struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
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pd->atomic_xfer = false;
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return sh_mobile_xfer(pd, msgs, num);
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}
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static int sh_mobile_i2c_xfer_atomic(struct i2c_adapter *adapter,
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struct i2c_msg *msgs,
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int num)
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{
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struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
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pd->atomic_xfer = true;
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return sh_mobile_xfer(pd, msgs, num);
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}
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static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
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}
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static const struct i2c_algorithm sh_mobile_i2c_algorithm = {
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.functionality = sh_mobile_i2c_func,
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.master_xfer = sh_mobile_i2c_xfer,
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.functionality = sh_mobile_i2c_func,
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.master_xfer = sh_mobile_i2c_xfer,
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.master_xfer_atomic = sh_mobile_i2c_xfer_atomic,
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};
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static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
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