Commit 89f845a6 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
Browse files

i2c: omap: Add the master_xfer_atomic hook 



Add the master_xfer_atomic hook to enable i2c transactions in irq
disabled contexts like the poweroff case.

Signed-off-by: default avatarTero Kristo <t-kristo@ti.com>
Signed-off-by: default avatarKeerthy <j-keerthy@ti.com>
[wsa: simplified code a little: 'timeout = !ret']
Reviewed-by: default avatarSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 77c1e1e0

drivers/i2c/busses/i2c-omap.c

+63 −13
Original line number Diff line number Diff line
@@ -269,6 +269,8 @@ static const u8 reg_map_ip_v2[] = { 
	[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,

};



static int omap_i2c_xfer_data(struct omap_i2c_dev *omap);



static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap,

				      int reg, u16 val)

{
@@ -648,15 +650,28 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx) 
			(1000 * omap->speed / 8);

}



static void omap_i2c_wait(struct omap_i2c_dev *omap)

{

	u16 stat;

	u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);

	int count = 0;



	do {

		stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);

		count++;

	} while (!(stat & mask) && count < 5);

}



/*

 * Low level master read/write transaction.

 */

static int omap_i2c_xfer_msg(struct i2c_adapter *adap,

			     struct i2c_msg *msg, int stop)

			     struct i2c_msg *msg, int stop, bool polling)

{

	struct omap_i2c_dev *omap = i2c_get_adapdata(adap);

	unsigned long timeout;

	u16 w;

	int ret;



	dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",

		msg->addr, msg->len, msg->flags, stop);
@@ -680,6 +695,7 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, 
	w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;

	omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);



	if (!polling)

		reinit_completion(&omap->cmd_complete);

	omap->cmd_err = 0;
@@ -732,8 +748,18 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, 
	 * REVISIT: We should abort the transfer on signals, but the bus goes

	 * into arbitration and we're currently unable to recover from it.

	 */

	if (!polling) {

		timeout = wait_for_completion_timeout(&omap->cmd_complete,

						      OMAP_I2C_TIMEOUT);

	} else {

		do {

			omap_i2c_wait(omap);

			ret = omap_i2c_xfer_data(omap);

		} while (ret == -EAGAIN);



		timeout = !ret;

	}



	if (timeout == 0) {

		dev_err(omap->dev, "controller timed out\n");

		omap_i2c_reset(omap);
@@ -772,7 +798,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, 
 * to do the work during IRQ processing.

 */

static int

omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num,

		     bool polling)

{

	struct omap_i2c_dev *omap = i2c_get_adapdata(adap);

	int i;
@@ -794,7 +821,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
		omap->set_mpu_wkup_lat(omap->dev, omap->latency);



	for (i = 0; i < num; i++) {

		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));

		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)),

				      polling);

		if (r != 0)

			break;

	}
@@ -813,6 +841,18 @@ out: 
	return r;

}



static int

omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

{

	return omap_i2c_xfer_common(adap, msgs, num, false);

}



static int

omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

{

	return omap_i2c_xfer_common(adap, msgs, num, true);

}



static u32

omap_i2c_func(struct i2c_adapter *adap)

{
@@ -1035,10 +1075,8 @@ omap_i2c_isr(int irq, void *dev_id) 
	return ret;

}



static irqreturn_t

omap_i2c_isr_thread(int this_irq, void *dev_id)

static int omap_i2c_xfer_data(struct omap_i2c_dev *omap)

{

	struct omap_i2c_dev *omap = dev_id;

	u16 bits;

	u16 stat;

	int err = 0, count = 0;
@@ -1056,7 +1094,8 @@ omap_i2c_isr_thread(int this_irq, void *dev_id) 


		if (!stat) {

			/* my work here is done */

			goto out;

			err = -EAGAIN;

			break;

		}



		dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat);
@@ -1165,14 +1204,25 @@ omap_i2c_isr_thread(int this_irq, void *dev_id) 
		}

	} while (stat);



	omap_i2c_complete_cmd(omap, err);

	return err;

}



static irqreturn_t

omap_i2c_isr_thread(int this_irq, void *dev_id)

{

	int ret;

	struct omap_i2c_dev *omap = dev_id;



	ret = omap_i2c_xfer_data(omap);

	if (ret != -EAGAIN)

		omap_i2c_complete_cmd(omap, ret);



out:

	return IRQ_HANDLED;

}



static const struct i2c_algorithm omap_i2c_algo = {

	.master_xfer	= omap_i2c_xfer,

	.master_xfer	= omap_i2c_xfer_irq,

	.master_xfer_atomic	= omap_i2c_xfer_polling,

	.functionality	= omap_i2c_func,

};

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