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Commit 63cab195 authored by Anurag Kumar Vulisha's avatar Anurag Kumar Vulisha Committed by Wolfram Sang
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i2c: removed work arounds in i2c driver for Zynq Ultrascale+ MPSoC 



Cadence 1.0 version has bugs which have been fixed in the cadence 1.4 version.
This patch removes the quirks present in the driver for cadence 1.4 version.

Signed-off-by: default avatarAnurag Kumar Vulisha <anuragku@xilinx.com>
[wsa: fixed indentation issues in r1p10_i2c_def]
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent d57f5ded

Documentation/devicetree/bindings/i2c/i2c-cadence.txt

+5 −1
Original line number Diff line number Diff line
@@ -2,7 +2,11 @@ Binding for the Cadence I2C controller 


Required properties:

  - reg: Physical base address and size of the controller's register area.

  - compatible: Compatibility string. Must be 'cdns,i2c-r1p10'.

  - compatible: Should contain one of:

		* "cdns,i2c-r1p10"

		Note:	Use this when cadence i2c controller version 1.0 is used.

		* "cdns,i2c-r1p14"

		Note:	Use this when cadence i2c controller version 1.4 is used.

  - clocks: Input clock specifier. Refer to common clock bindings.

  - interrupts: Interrupt specifier. Refer to interrupt bindings.

  - #address-cells: Should be 1.

drivers/i2c/busses/i2c-cadence.c

+57 −11
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/io.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/of.h>



/* Register offsets for the I2C device. */

#define CDNS_I2C_CR_OFFSET		0x00 /* Control Register, RW */
@@ -113,6 +114,8 @@ 


#define CDNS_I2C_TIMEOUT_MAX	0xFF



#define CDNS_I2C_BROKEN_HOLD_BIT	BIT(0)



#define cdns_i2c_readreg(offset)       readl_relaxed(id->membase + offset)

#define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset)
@@ -135,6 +138,7 @@ 
 * @bus_hold_flag:	Flag used in repeated start for clearing HOLD bit

 * @clk:		Pointer to struct clk

 * @clk_rate_change_nb:	Notifier block for clock rate changes

 * @quirks:		flag for broken hold bit usage in r1p10

 */

struct cdns_i2c {

	void __iomem *membase;
@@ -154,6 +158,11 @@ struct cdns_i2c { 
	unsigned int bus_hold_flag;

	struct clk *clk;

	struct notifier_block clk_rate_change_nb;

	u32 quirks;

};



struct cdns_platform_data {

	u32 quirks;

};



#define to_cdns_i2c(_nb)	container_of(_nb, struct cdns_i2c, \
@@ -172,6 +181,12 @@ static void cdns_i2c_clear_bus_hold(struct cdns_i2c *id) 
		cdns_i2c_writereg(reg & ~CDNS_I2C_CR_HOLD, CDNS_I2C_CR_OFFSET);

}



static inline bool cdns_is_holdquirk(struct cdns_i2c *id, bool hold_wrkaround)

{

	return (hold_wrkaround &&

		(id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1));

}



/**

 * cdns_i2c_isr - Interrupt handler for the I2C device

 * @irq:	irq number for the I2C device
@@ -186,6 +201,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) 
{

	unsigned int isr_status, avail_bytes, updatetx;

	unsigned int bytes_to_send;

	bool hold_quirk;

	struct cdns_i2c *id = ptr;

	/* Signal completion only after everything is updated */

	int done_flag = 0;
@@ -208,6 +224,8 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) 
	if (id->recv_count > id->curr_recv_count)

		updatetx = 1;



	hold_quirk = (id->quirks & CDNS_I2C_BROKEN_HOLD_BIT) && updatetx;



	/* When receiving, handle data interrupt and completion interrupt */

	if (id->p_recv_buf &&

	    ((isr_status & CDNS_I2C_IXR_COMP) ||
@@ -229,8 +247,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) 
			id->recv_count--;

			id->curr_recv_count--;



			if (updatetx &&

			    (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1))

			if (cdns_is_holdquirk(id, hold_quirk))

				break;

		}
@@ -241,8 +258,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) 
		 * maintain transfer size non-zero while performing a large

		 * receive operation.

		 */

		if (updatetx &&

		    (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1)) {

		if (cdns_is_holdquirk(id, hold_quirk)) {

			/* wait while fifo is full */

			while (cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) !=

			       (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH))
@@ -264,6 +280,22 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) 
						  CDNS_I2C_XFER_SIZE_OFFSET);

				id->curr_recv_count = id->recv_count;

			}

		} else if (id->recv_count && !hold_quirk &&

						!id->curr_recv_count) {



			/* Set the slave address in address register*/

			cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,

						CDNS_I2C_ADDR_OFFSET);



			if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) {

				cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE,

						CDNS_I2C_XFER_SIZE_OFFSET);

				id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE;

			} else {

				cdns_i2c_writereg(id->recv_count,

						CDNS_I2C_XFER_SIZE_OFFSET);

				id->curr_recv_count = id->recv_count;

			}

		}



		/* Clear hold (if not repeated start) and signal completion */
@@ -535,11 +567,13 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 
	int ret, count;

	u32 reg;

	struct cdns_i2c *id = adap->algo_data;

	bool hold_quirk;



	/* Check if the bus is free */

	if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA)

		return -EAGAIN;



	hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);

	/*

	 * Set the flag to one when multiple messages are to be

	 * processed with a repeated start.
@@ -552,7 +586,7 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 
		 * followed by any other message, an error is returned

		 * indicating that this sequence is not supported.

		 */

		for (count = 0; count < num - 1; count++) {

		for (count = 0; (count < num - 1 && hold_quirk); count++) {

			if (msgs[count].flags & I2C_M_RD) {

				dev_warn(adap->dev.parent,

					 "Can't do repeated start after a receive message\n");
@@ -815,6 +849,17 @@ static int __maybe_unused cdns_i2c_resume(struct device *_dev) 
static SIMPLE_DEV_PM_OPS(cdns_i2c_dev_pm_ops, cdns_i2c_suspend,

			 cdns_i2c_resume);



static const struct cdns_platform_data r1p10_i2c_def = {

	.quirks = CDNS_I2C_BROKEN_HOLD_BIT,

};



static const struct of_device_id cdns_i2c_of_match[] = {

	{ .compatible = "cdns,i2c-r1p10", .data = &r1p10_i2c_def },

	{ .compatible = "cdns,i2c-r1p14",},

	{ /* end of table */ }

};

MODULE_DEVICE_TABLE(of, cdns_i2c_of_match);



/**

 * cdns_i2c_probe - Platform registration call

 * @pdev:	Handle to the platform device structure
@@ -830,6 +875,7 @@ static int cdns_i2c_probe(struct platform_device *pdev) 
	struct resource *r_mem;

	struct cdns_i2c *id;

	int ret;

	const struct of_device_id *match;



	id = devm_kzalloc(&pdev->dev, sizeof(*id), GFP_KERNEL);

	if (!id)
@@ -837,6 +883,12 @@ static int cdns_i2c_probe(struct platform_device *pdev) 


	platform_set_drvdata(pdev, id);



	match = of_match_node(cdns_i2c_of_match, pdev->dev.of_node);

	if (match && match->data) {

		const struct cdns_platform_data *data = match->data;

		id->quirks = data->quirks;

	}



	r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	id->membase = devm_ioremap_resource(&pdev->dev, r_mem);

	if (IS_ERR(id->membase))
@@ -935,12 +987,6 @@ static int cdns_i2c_remove(struct platform_device *pdev) 
	return 0;

}



static const struct of_device_id cdns_i2c_of_match[] = {

	{ .compatible = "cdns,i2c-r1p10", },

	{ /* end of table */ }

};

MODULE_DEVICE_TABLE(of, cdns_i2c_of_match);



static struct platform_driver cdns_i2c_drv = {

	.driver = {

		.name  = DRIVER_NAME,