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Commit e2e5a2c6 authored by Kamal Dasu's avatar Kamal Dasu Committed by Wolfram Sang
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i2c: brcmstb: Adding support for CM and DSL SoCs 



Broadcoms DSL, CM (cable modem)and STB I2C core implementation have
8 data in/out registers that can transfer 8 bytes or 32 bytes max.
Cable and DSL "Peripheral" i2c cores use single byte per data
register and the STB can use 4 byte per data register transfer.
Adding support to take care of this difference. Accordingly added
the compatible string for SoCs using the "Peripheral" I2C block.

Signed-off-by: default avatarKamal Dasu <kdasu.kdev@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 8378d01f

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

+1 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ Broadcom stb bsc iic master controller 


Required properties:



- compatible: should be "brcm,brcmstb-i2c"

- compatible: should be "brcm,brcmstb-i2c" or "brcm,brcmper-i2c"

- clock-frequency: 32-bit decimal value of iic master clock freqency in Hz

		   valid values are 375000, 390000, 187500, 200000

		   93750, 97500, 46875 and 50000

drivers/i2c/busses/i2c-brcmstb.c

+56 −24
Original line number Diff line number Diff line
@@ -25,13 +25,16 @@ 
#include <linux/version.h>



#define N_DATA_REGS					8

#define N_DATA_BYTES					(N_DATA_REGS * 4)



/* BSC count register field definitions */

#define BSC_CNT_REG1_MASK				0x0000003f

/*

 * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register

 * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per

 * data register whereas STB SoCs use 4 byte per data register transfer,

 * account for this difference in total count per transaction and mask to

 * use.

 */

#define BSC_CNT_REG1_MASK(nb)	(nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0))

#define BSC_CNT_REG1_SHIFT	0

#define BSC_CNT_REG2_MASK				0x00000fc0

#define BSC_CNT_REG2_SHIFT				6



/* BSC CTL register field definitions */

#define BSC_CTL_REG_DTF_MASK				0x00000003
@@ -41,7 +44,7 @@ 
#define BSC_CTL_REG_INT_EN_SHIFT			6

#define BSC_CTL_REG_DIV_CLK_MASK			0x00000080



/* BSC_IIC_ENABLE r/w enable and interrupt field defintions */

/* BSC_IIC_ENABLE r/w enable and interrupt field definitions */

#define BSC_IIC_EN_RESTART_MASK				0x00000040

#define BSC_IIC_EN_NOSTART_MASK				0x00000020

#define BSC_IIC_EN_NOSTOP_MASK				0x00000010
@@ -169,6 +172,7 @@ struct brcmstb_i2c_dev { 
	struct completion done;

	bool is_suspended;

	u32 clk_freq_hz;

	int data_regsz;

};



/* register accessors for both be and le cpu arch */
@@ -186,6 +190,16 @@ struct brcmstb_i2c_dev { 
#define bsc_writel(_dev, _val, _reg)					\

	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))



static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)

{

	return (N_DATA_REGS * dev->data_regsz);

}



static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)

{

	return dev->data_regsz;

}



static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,

					   bool int_en)

{
@@ -323,14 +337,16 @@ static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev, 
				     u8 *buf, unsigned int len,

				     struct i2c_msg *pmsg)

{

	int cnt, byte, rc;

	int cnt, byte, i, rc;

	enum bsc_xfer_cmd cmd;

	u32 ctl_reg;

	struct bsc_regs *pi2creg = dev->bsc_regmap;

	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;

	int data_regsz = brcmstb_i2c_get_data_regsz(dev);

	int xfersz = brcmstb_i2c_get_xfersz(dev);



	/* see if the transaction needs to check NACK conditions */

	if (no_ack || len <= N_DATA_BYTES) {

	if (no_ack || len <= xfersz) {

		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK

			: CMD_WR_NOACK;

		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
@@ -348,20 +364,22 @@ static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev, 
		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;



	/* set the read/write length */

	bsc_writel(dev, BSC_CNT_REG1_MASK & (len << BSC_CNT_REG1_SHIFT),

		   cnt_reg);

	bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &

		   (len << BSC_CNT_REG1_SHIFT), cnt_reg);



	/* Write data into data_in register */



	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {

		for (cnt = 0; cnt < len; cnt += 4) {

		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {

			u32 word = 0;



			for (byte = 0; byte < 4; byte++) {

				word >>= 8;

			for (byte = 0; byte < data_regsz; byte++) {

				word >>= BITS_PER_BYTE;

				if ((cnt + byte) < len)

					word |= buf[cnt + byte] << 24;

					word |= buf[cnt + byte] <<

					(BITS_PER_BYTE * (data_regsz - 1));

			}

			bsc_writel(dev, word, data_in[cnt >> 2]);

			bsc_writel(dev, word, data_in[i]);

		}

	}
@@ -373,14 +391,15 @@ static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev, 
		return rc;

	}



	/* Read data from data_out register */

	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {

		for (cnt = 0; cnt < len; cnt += 4) {

			u32 data = bsc_readl(dev, data_out[cnt >> 2]);

		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {

			u32 data = bsc_readl(dev, data_out[i]);



			for (byte = 0; byte < 4 &&

			for (byte = 0; byte < data_regsz &&

				     (byte + cnt) < len; byte++) {

				buf[cnt + byte] = data & 0xff;

				data >>= 8;

				data >>= BITS_PER_BYTE;

			}

		}

	}
@@ -448,6 +467,7 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter, 
	int bytes_to_xfer;

	u8 *tmp_buf;

	int len = 0;

	int xfersz = brcmstb_i2c_get_xfersz(dev);



	if (dev->is_suspended)

		return -EBUSY;
@@ -482,9 +502,9 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter, 


		/* Perform data transfer */

		while (len) {

			bytes_to_xfer = min(len, N_DATA_BYTES);

			bytes_to_xfer = min(len, xfersz);



			if (len <= N_DATA_BYTES && i == (num - 1))

			if (len <= xfersz && i == (num - 1))

				brcmstb_set_i2c_start_stop(dev,

							   ~(COND_START_STOP));
@@ -542,8 +562,12 @@ static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev) 


static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)

{

	/* 4 byte data register */

	if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))

		/* set 4 byte data in/out xfers  */

		dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;

	else

		dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;



	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);

	/* set bus speed */

	brcmstb_i2c_set_bus_speed(dev);
@@ -608,6 +632,13 @@ static int brcmstb_i2c_probe(struct platform_device *pdev) 
		dev->clk_freq_hz = bsc_clk[0].hz;

	}



	/* set the data in/out register size for compatible SoCs */

	if (of_device_is_compatible(dev->device->of_node,

				    "brcmstb,brcmper-i2c"))

		dev->data_regsz = sizeof(u8);

	else

		dev->data_regsz = sizeof(u32);



	brcmstb_i2c_set_bsc_reg_defaults(dev);



	/* Add the i2c adapter */
@@ -674,6 +705,7 @@ static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend, 


static const struct of_device_id brcmstb_i2c_of_match[] = {

	{.compatible = "brcm,brcmstb-i2c"},

	{.compatible = "brcm,brcmper-i2c"},

	{},

};

MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);