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openwrt_NSS_ACW/target/linux/generic/backport-5.4/806-v5.8-i2c-pxa-re-arrange-functions-to-flow-better.patch
Hauke Mehrtens 68d9cb8214 kernel: Update kernel 5.4 to version 5.4.50 
Run tested: ath79, ipq40xx
Build tested: ath79, ipq40xx

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2020-07-04 21:12:42 +02:00

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From: Russell King <rmk+kernel@armlinux.org.uk>
Bcc: linux@mail.armlinux.org.uk
Cc: linux-i2c@vger.kernel.org
Subject: [PATCH 04/17] i2c: pxa: re-arrange functions to flow better
MIME-Version: 1.0
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset="utf-8"
Re-arrange the PXA I2C code to avoid forward declarations, and keep
similar functionality (e.g. the non-IRQ mode support) together. This
improves code readability.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
drivers/i2c/busses/i2c-pxa.c | 325 +++++++++++++++++------------------
1 file changed, 162 insertions(+), 163 deletions(-)
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -326,7 +326,6 @@ static void i2c_pxa_scream_blue_murder(s
#endif /* ifdef DEBUG / else */
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
-static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
{
@@ -697,34 +696,6 @@ static inline void i2c_pxa_stop_message(
writel(icr, _ICR(i2c));
}
-static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
-{
- /* make timeout the same as for interrupt based functions */
- long timeout = 2 * DEF_TIMEOUT;
-
- /*
- * Wait for the bus to become free.
- */
- while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
- udelay(1000);
- show_state(i2c);
- }
-
- if (timeout < 0) {
- show_state(i2c);
- dev_err(&i2c->adap.dev,
- "i2c_pxa: timeout waiting for bus free\n");
- return I2C_RETRY;
- }
-
- /*
- * Set master mode.
- */
- writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
-
- return 0;
-}
-
/*
* PXA I2C send master code
* 1. Load master code to IDBR and send it.
@@ -753,140 +724,6 @@ static int i2c_pxa_send_mastercode(struc
return (timeout == 0) ? I2C_RETRY : 0;
}
-static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
- struct i2c_msg *msg, int num)
-{
- unsigned long timeout = 500000; /* 5 seconds */
- int ret = 0;
-
- ret = i2c_pxa_pio_set_master(i2c);
- if (ret)
- goto out;
-
- i2c->msg = msg;
- i2c->msg_num = num;
- i2c->msg_idx = 0;
- i2c->msg_ptr = 0;
- i2c->irqlogidx = 0;
-
- i2c_pxa_start_message(i2c);
-
- while (i2c->msg_num > 0 && --timeout) {
- i2c_pxa_handler(0, i2c);
- udelay(10);
- }
-
- i2c_pxa_stop_message(i2c);
-
- /*
- * We place the return code in i2c->msg_idx.
- */
- ret = i2c->msg_idx;
-
-out:
- if (timeout == 0) {
- i2c_pxa_scream_blue_murder(i2c, "timeout");
- ret = I2C_RETRY;
- }
-
- return ret;
-}
-
-/*
- * We are protected by the adapter bus mutex.
- */
-static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
-{
- long timeout;
- int ret;
-
- /*
- * Wait for the bus to become free.
- */
- ret = i2c_pxa_wait_bus_not_busy(i2c);
- if (ret) {
- dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
- goto out;
- }
-
- /*
- * Set master mode.
- */
- ret = i2c_pxa_set_master(i2c);
- if (ret) {
- dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
- goto out;
- }
-
- if (i2c->high_mode) {
- ret = i2c_pxa_send_mastercode(i2c);
- if (ret) {
- dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
- goto out;
- }
- }
-
- spin_lock_irq(&i2c->lock);
-
- i2c->msg = msg;
- i2c->msg_num = num;
- i2c->msg_idx = 0;
- i2c->msg_ptr = 0;
- i2c->irqlogidx = 0;
-
- i2c_pxa_start_message(i2c);
-
- spin_unlock_irq(&i2c->lock);
-
- /*
- * The rest of the processing occurs in the interrupt handler.
- */
- timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
- i2c_pxa_stop_message(i2c);
-
- /*
- * We place the return code in i2c->msg_idx.
- */
- ret = i2c->msg_idx;
-
- if (!timeout && i2c->msg_num) {
- i2c_pxa_scream_blue_murder(i2c, "timeout");
- ret = I2C_RETRY;
- }
-
- out:
- return ret;
-}
-
-static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
- struct i2c_msg msgs[], int num)
-{
- struct pxa_i2c *i2c = adap->algo_data;
- int ret, i;
-
- /* If the I2C controller is disabled we need to reset it
- (probably due to a suspend/resume destroying state). We do
- this here as we can then avoid worrying about resuming the
- controller before its users. */
- if (!(readl(_ICR(i2c)) & ICR_IUE))
- i2c_pxa_reset(i2c);
-
- for (i = adap->retries; i >= 0; i--) {
- ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
- if (ret != I2C_RETRY)
- goto out;
-
- if (i2c_debug)
- dev_dbg(&adap->dev, "Retrying transmission\n");
- udelay(100);
- }
- i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
- ret = -EREMOTEIO;
- out:
- i2c_pxa_set_slave(i2c, ret);
- return ret;
-}
-
/*
* i2c_pxa_master_complete - complete the message and wake up.
*/
@@ -1093,6 +930,71 @@ static irqreturn_t i2c_pxa_handler(int t
return IRQ_HANDLED;
}
+/*
+ * We are protected by the adapter bus mutex.
+ */
+static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
+{
+ long timeout;
+ int ret;
+
+ /*
+ * Wait for the bus to become free.
+ */
+ ret = i2c_pxa_wait_bus_not_busy(i2c);
+ if (ret) {
+ dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
+ goto out;
+ }
+
+ /*
+ * Set master mode.
+ */
+ ret = i2c_pxa_set_master(i2c);
+ if (ret) {
+ dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
+ goto out;
+ }
+
+ if (i2c->high_mode) {
+ ret = i2c_pxa_send_mastercode(i2c);
+ if (ret) {
+ dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
+ goto out;
+ }
+ }
+
+ spin_lock_irq(&i2c->lock);
+
+ i2c->msg = msg;
+ i2c->msg_num = num;
+ i2c->msg_idx = 0;
+ i2c->msg_ptr = 0;
+ i2c->irqlogidx = 0;
+
+ i2c_pxa_start_message(i2c);
+
+ spin_unlock_irq(&i2c->lock);
+
+ /*
+ * The rest of the processing occurs in the interrupt handler.
+ */
+ timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+ i2c_pxa_stop_message(i2c);
+
+ /*
+ * We place the return code in i2c->msg_idx.
+ */
+ ret = i2c->msg_idx;
+
+ if (!timeout && i2c->msg_num) {
+ i2c_pxa_scream_blue_murder(i2c, "timeout");
+ ret = I2C_RETRY;
+ }
+
+ out:
+ return ret;
+}
static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
@@ -1126,6 +1028,103 @@ static const struct i2c_algorithm i2c_px
.functionality = i2c_pxa_functionality,
};
+/* Non-interrupt mode support */
+static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
+{
+ /* make timeout the same as for interrupt based functions */
+ long timeout = 2 * DEF_TIMEOUT;
+
+ /*
+ * Wait for the bus to become free.
+ */
+ while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
+ udelay(1000);
+ show_state(i2c);
+ }
+
+ if (timeout < 0) {
+ show_state(i2c);
+ dev_err(&i2c->adap.dev,
+ "i2c_pxa: timeout waiting for bus free\n");
+ return I2C_RETRY;
+ }
+
+ /*
+ * Set master mode.
+ */
+ writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
+
+ return 0;
+}
+
+static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
+ struct i2c_msg *msg, int num)
+{
+ unsigned long timeout = 500000; /* 5 seconds */
+ int ret = 0;
+
+ ret = i2c_pxa_pio_set_master(i2c);
+ if (ret)
+ goto out;
+
+ i2c->msg = msg;
+ i2c->msg_num = num;
+ i2c->msg_idx = 0;
+ i2c->msg_ptr = 0;
+ i2c->irqlogidx = 0;
+
+ i2c_pxa_start_message(i2c);
+
+ while (i2c->msg_num > 0 && --timeout) {
+ i2c_pxa_handler(0, i2c);
+ udelay(10);
+ }
+
+ i2c_pxa_stop_message(i2c);
+
+ /*
+ * We place the return code in i2c->msg_idx.
+ */
+ ret = i2c->msg_idx;
+
+out:
+ if (timeout == 0) {
+ i2c_pxa_scream_blue_murder(i2c, "timeout");
+ ret = I2C_RETRY;
+ }
+
+ return ret;
+}
+
+static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
+ struct i2c_msg msgs[], int num)
+{
+ struct pxa_i2c *i2c = adap->algo_data;
+ int ret, i;
+
+ /* If the I2C controller is disabled we need to reset it
+ (probably due to a suspend/resume destroying state). We do
+ this here as we can then avoid worrying about resuming the
+ controller before its users. */
+ if (!(readl(_ICR(i2c)) & ICR_IUE))
+ i2c_pxa_reset(i2c);
+
+ for (i = adap->retries; i >= 0; i--) {
+ ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
+ if (ret != I2C_RETRY)
+ goto out;
+
+ if (i2c_debug)
+ dev_dbg(&adap->dev, "Retrying transmission\n");
+ udelay(100);
+ }
+ i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
+ ret = -EREMOTEIO;
+ out:
+ i2c_pxa_set_slave(i2c, ret);
+ return ret;
+}
+
static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
.master_xfer = i2c_pxa_pio_xfer,
.functionality = i2c_pxa_functionality,
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