Commit b03cfc5b authored by Mario Huettel's avatar Mario Huettel Committed by Marc Kleine-Budde
Browse files

can: m_can: Enable M_CAN version dependent initialization 



This patch adapts the initialization of the M_CAN. So it can be used
with all versions >= 3.0.x.

Changes:
* Added version element to m_can_priv structure to hold M_CAN version.
* Renamed bittiming structs for version 3.0.x
* Added new bittiming structs for version >= 3.1.x
* Function alloc_m_can_dev takes 2 new arguments. The TX FIFO size and the
  base address of the module.
* Chip configuration for CAN_CTRLMODE_LOOPBACK is changed: Enabled
  CCCR_MON bit. In combination with TEST_LBCK it activates the internal
  loopback mode. Leaving CCCR_MON '0' results in external loopback mode.
* Clocks are temporarily enabled by platform_propbe function in order to
  allow read access to the Core Release register and the Control Register.
  Registers are used to detect M_CAN version and optional Non-ISO Feature.

Initialization of M_CAN for version >= 3.1.x:
* TX FIFO of M_CAN is used to transmit frames. The driver does not need to
  stop the tx queue after each frame sent.
* Initialization of TX Event FIFO is added.
* NON-ISO is fixed for all M_CAN versions < 3.2.x. Version 3.2.x _can_ have
  the NISO (Non-ISO) bit which can switch the mode of the M_CAN to Non-ISO
  mode. This bit does not have to be writeable. Therefore it is checked.
  If it is writable Non-ISO support is added to the controllers supported
  CAN modes.

New Functions:
* Function to check the Core Release version. The read value determines the
  behaviour of the driver.
* Function to check if the NISO bit for version >= 3.2.x is implemented.

Signed-off-by: default avatarMario Huettel <mario.huettel@gmx.net>
Reviewed-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: default avatarQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 5e1bd15a

drivers/net/can/m_can/m_can.c

+269 −71
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ 
#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>



#include <linux/iopoll.h>

#include <linux/can/dev.h>



/* napi related */
@@ -107,6 +107,14 @@ enum m_can_mram_cfg { 
	MRAM_CFG_NUM,

};



/* Core Release Register (CREL) */

#define CREL_REL_SHIFT		28

#define CREL_REL_MASK		(0xF << CREL_REL_SHIFT)

#define CREL_STEP_SHIFT		24

#define CREL_STEP_MASK		(0xF << CREL_STEP_SHIFT)

#define CREL_SUBSTEP_SHIFT	20

#define CREL_SUBSTEP_MASK	(0xF << CREL_SUBSTEP_SHIFT)



/* Data Bit Timing & Prescaler Register (DBTP) */

#define DBTP_TDC		BIT(23)

#define DBTP_DBRP_SHIFT		16
@@ -342,6 +350,7 @@ struct m_can_priv { 
	struct clk *cclk;

	void __iomem *base;

	u32 irqstatus;

	int version;



	/* message ram configuration */

	void __iomem *mram_base;
@@ -833,7 +842,7 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static const struct can_bittiming_const m_can_bittiming_const = {

static const struct can_bittiming_const m_can_bittiming_const_30X = {

	.name = KBUILD_MODNAME,

	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */

	.tseg1_max = 64,
@@ -845,7 +854,7 @@ static const struct can_bittiming_const m_can_bittiming_const = { 
	.brp_inc = 1,

};



static const struct can_bittiming_const m_can_data_bittiming_const = {

static const struct can_bittiming_const m_can_data_bittiming_const_30X = {

	.name = KBUILD_MODNAME,

	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */

	.tseg1_max = 16,
@@ -857,6 +866,30 @@ static const struct can_bittiming_const m_can_data_bittiming_const = { 
	.brp_inc = 1,

};



static const struct can_bittiming_const m_can_bittiming_const_31X = {

	.name = KBUILD_MODNAME,

	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */

	.tseg1_max = 256,

	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */

	.tseg2_max = 128,

	.sjw_max = 128,

	.brp_min = 1,

	.brp_max = 512,

	.brp_inc = 1,

};



static const struct can_bittiming_const m_can_data_bittiming_const_31X = {

	.name = KBUILD_MODNAME,

	.tseg1_min = 1,		/* Time segment 1 = prop_seg + phase_seg1 */

	.tseg1_max = 32,

	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */

	.tseg2_max = 16,

	.sjw_max = 16,

	.brp_min = 1,

	.brp_max = 32,

	.brp_inc = 1,

};



static int m_can_set_bittiming(struct net_device *dev)

{

	struct m_can_priv *priv = netdev_priv(dev);
@@ -928,29 +961,53 @@ static void m_can_chip_config(struct net_device *dev) 
		     priv->mcfg[MRAM_RXF1].off);



	cccr = m_can_read(priv, M_CAN_CCCR);

	cccr &= ~(CCCR_TEST | CCCR_MON | (CCCR_CMR_MASK << CCCR_CMR_SHIFT) |

		(CCCR_CME_MASK << CCCR_CME_SHIFT));

	test = m_can_read(priv, M_CAN_TEST);

	test &= ~TEST_LBCK;

	if (priv->version == 30) {

	/* Version 3.0.x */



	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)

		cccr |= CCCR_MON;

		cccr &= ~(CCCR_TEST | CCCR_MON |

			(CCCR_CMR_MASK << CCCR_CMR_SHIFT) |

			(CCCR_CME_MASK << CCCR_CME_SHIFT));



		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)

			cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;



	} else {

	/* Version 3.1.x or 3.2.x */

		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE);



		/* Only 3.2.x has NISO Bit implemented */

		if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)

			cccr |= CCCR_NISO;



		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)

			cccr |= (CCCR_BRSE | CCCR_FDOE);

	}



	/* Loopback Mode */

	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {

		cccr |= CCCR_TEST;

		cccr |= CCCR_TEST | CCCR_MON;

		test |= TEST_LBCK;

	}



	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)

		cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;

	/* Enable Monitoring (all versions) */

	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)

		cccr |= CCCR_MON;



	/* Write config */

	m_can_write(priv, M_CAN_CCCR, cccr);

	m_can_write(priv, M_CAN_TEST, test);



	/* enable interrupts */

	/* Enable interrupts */

	m_can_write(priv, M_CAN_IR, IR_ALL_INT);

	if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))

		m_can_write(priv, M_CAN_IE, IR_ALL_INT & ~IR_ERR_LEC_30X);

		if (priv->version == 30)

			m_can_write(priv, M_CAN_IE, IR_ALL_INT &

				    ~(IR_ERR_LEC_30X));

		else

			m_can_write(priv, M_CAN_IE, IR_ALL_INT &

				    ~(IR_ERR_LEC_31X));

	else

		m_can_write(priv, M_CAN_IE, IR_ALL_INT);
@@ -994,33 +1051,140 @@ static void free_m_can_dev(struct net_device *dev) 
	free_candev(dev);

}



static struct net_device *alloc_m_can_dev(void)

/* Checks core release number of M_CAN

 * returns 0 if an unsupported device is detected

 * else it returns the release and step coded as:

 * return value = 10 * <release> + 1 * <step>

 */

static int m_can_check_core_release(void __iomem *m_can_base)

{

	u32 crel_reg;

	u8 rel;

	u8 step;

	int res;

	struct m_can_priv temp_priv = {

		.base = m_can_base

	};



	/* Read Core Release Version and split into version number

	 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;

	 */

	crel_reg = m_can_read(&temp_priv, M_CAN_CREL);

	rel = (u8)((crel_reg & CREL_REL_MASK) >> CREL_REL_SHIFT);

	step = (u8)((crel_reg & CREL_STEP_MASK) >> CREL_STEP_SHIFT);



	if (rel == 3) {

		/* M_CAN v3.x.y: create return value */

		res = 30 + step;

	} else {

		/* Unsupported M_CAN version */

		res = 0;

	}



	return res;

}



/* Selectable Non ISO support only in version 3.2.x

 * This function checks if the bit is writable.

 */

static bool m_can_niso_supported(const struct m_can_priv *priv)

{

	u32 cccr_reg, cccr_poll;

	int niso_timeout;



	m_can_config_endisable(priv, true);

	cccr_reg = m_can_read(priv, M_CAN_CCCR);

	cccr_reg |= CCCR_NISO;

	m_can_write(priv, M_CAN_CCCR, cccr_reg);



	niso_timeout = readl_poll_timeout((priv->base + M_CAN_CCCR), cccr_poll,

					  (cccr_poll == cccr_reg), 0, 10);



	/* Clear NISO */

	cccr_reg &= ~(CCCR_NISO);

	m_can_write(priv, M_CAN_CCCR, cccr_reg);



	m_can_config_endisable(priv, false);



	/* return false if time out (-ETIMEDOUT), else return true */

	return !niso_timeout;

}



static struct net_device *alloc_m_can_dev(struct platform_device *pdev,

					  void __iomem *addr, u32 tx_fifo_size)

{

	struct net_device *dev;

	struct m_can_priv *priv;

	int m_can_version;

	unsigned int echo_buffer_count;



	dev = alloc_candev(sizeof(*priv), 1);

	if (!dev)

		return NULL;

	m_can_version = m_can_check_core_release(addr);

	/* return if unsupported version */

	if (!m_can_version) {

		dev = NULL;

		goto return_dev;

	}



	/* If version < 3.1.x, then only one echo buffer is used */

	echo_buffer_count = ((m_can_version == 30)

				? 1U

				: (unsigned int)tx_fifo_size);



	dev = alloc_candev(sizeof(*priv), echo_buffer_count);

	if (!dev) {

		dev = NULL;

		goto return_dev;

	}

	priv = netdev_priv(dev);

	netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);



	/* Shared properties of all M_CAN versions */

	priv->version = m_can_version;

	priv->dev = dev;

	priv->can.bittiming_const = &m_can_bittiming_const;

	priv->can.data_bittiming_const = &m_can_data_bittiming_const;

	priv->base = addr;

	priv->can.do_set_mode = m_can_set_mode;

	priv->can.do_get_berr_counter = m_can_get_berr_counter;



	/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.1 */

	can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);



	/* CAN_CTRLMODE_FD_NON_ISO can not be changed with M_CAN IP v3.0.1 */

	/* Set M_CAN supported operations */

	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |

					CAN_CTRLMODE_LISTENONLY |

					CAN_CTRLMODE_BERR_REPORTING |

					CAN_CTRLMODE_FD;



	/* Set properties depending on M_CAN version */

	switch (priv->version) {

	case 30:

		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */

		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);

		priv->can.bittiming_const = &m_can_bittiming_const_30X;

		priv->can.data_bittiming_const =

				&m_can_data_bittiming_const_30X;

		break;

	case 31:

		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */

		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);

		priv->can.bittiming_const = &m_can_bittiming_const_31X;

		priv->can.data_bittiming_const =

				&m_can_data_bittiming_const_31X;

		break;

	case 32:

		priv->can.bittiming_const = &m_can_bittiming_const_31X;

		priv->can.data_bittiming_const =

				&m_can_data_bittiming_const_31X;

		priv->can.ctrlmode_supported |= (m_can_niso_supported(priv)

						? CAN_CTRLMODE_FD_NON_ISO

						: 0);

		break;

	default:

		/* Unsupported device: free candev */

		free_m_can_dev(dev);

		dev_err(&pdev->dev, "Unsupported version number: %2d",

			priv->version);

		dev = NULL;

		break;

	}



return_dev:

	return dev;

}
@@ -1167,58 +1331,37 @@ static int register_m_can_dev(struct net_device *dev) 
	return register_candev(dev);

}



static int m_can_of_parse_mram(struct platform_device *pdev,

			       struct m_can_priv *priv)

static void m_can_of_parse_mram(struct m_can_priv *priv,

				const u32 *mram_config_vals)

{

	struct device_node *np = pdev->dev.of_node;

	struct resource *res;

	void __iomem *addr;

	u32 out_val[MRAM_CFG_LEN];

	int i, start, end, ret;



	/* message ram could be shared */

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");

	if (!res)

		return -ENODEV;



	addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));

	if (!addr)

		return -ENOMEM;

	int i, start, end;



	/* get message ram configuration */

	ret = of_property_read_u32_array(np, "bosch,mram-cfg",

					 out_val, sizeof(out_val) / 4);

	if (ret) {

		dev_err(&pdev->dev, "can not get message ram configuration\n");

		return -ENODEV;

	}



	priv->mram_base = addr;

	priv->mcfg[MRAM_SIDF].off = out_val[0];

	priv->mcfg[MRAM_SIDF].num = out_val[1];

	priv->mcfg[MRAM_SIDF].off = mram_config_vals[0];

	priv->mcfg[MRAM_SIDF].num = mram_config_vals[1];

	priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +

			priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;

	priv->mcfg[MRAM_XIDF].num = out_val[2];

	priv->mcfg[MRAM_XIDF].num = mram_config_vals[2];

	priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +

			priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;

	priv->mcfg[MRAM_RXF0].num = out_val[3] &

	priv->mcfg[MRAM_RXF0].num = mram_config_vals[3] &

			(RXFC_FS_MASK >> RXFC_FS_SHIFT);

	priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +

			priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;

	priv->mcfg[MRAM_RXF1].num = out_val[4] &

	priv->mcfg[MRAM_RXF1].num = mram_config_vals[4] &

			(RXFC_FS_MASK >> RXFC_FS_SHIFT);

	priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +

			priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;

	priv->mcfg[MRAM_RXB].num = out_val[5];

	priv->mcfg[MRAM_RXB].num = mram_config_vals[5];

	priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +

			priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;

	priv->mcfg[MRAM_TXE].num = out_val[6];

	priv->mcfg[MRAM_TXE].num = mram_config_vals[6];

	priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +

			priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;

	priv->mcfg[MRAM_TXB].num = out_val[7] &

	priv->mcfg[MRAM_TXB].num = mram_config_vals[7] &

			(TXBC_NDTB_MASK >> TXBC_NDTB_SHIFT);



	dev_dbg(&pdev->dev, "mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",

	dev_dbg(priv->device,

		"mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",

		priv->mram_base,

		priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,

		priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
@@ -1237,7 +1380,6 @@ static int m_can_of_parse_mram(struct platform_device *pdev, 
	for (i = start; i < end; i += 4)

		writel(0x0, priv->mram_base + i);



	return 0;

}



static int m_can_plat_probe(struct platform_device *pdev)
@@ -1246,38 +1388,86 @@ static int m_can_plat_probe(struct platform_device *pdev) 
	struct m_can_priv *priv;

	struct resource *res;

	void __iomem *addr;

	void __iomem *mram_addr;

	struct clk *hclk, *cclk;

	int irq, ret;

	struct device_node *np;

	u32 mram_config_vals[MRAM_CFG_LEN];

	u32 tx_fifo_size;



	np = pdev->dev.of_node;



	hclk = devm_clk_get(&pdev->dev, "hclk");

	cclk = devm_clk_get(&pdev->dev, "cclk");



	if (IS_ERR(hclk) || IS_ERR(cclk)) {

		dev_err(&pdev->dev, "no clock found\n");

		return -ENODEV;

		ret = -ENODEV;

		goto failed_ret;

	}



	/* Enable clocks. Necessary to read Core Release in order to determine

	 * M_CAN version

	 */

	ret = clk_prepare_enable(hclk);

	if (ret)

		goto disable_hclk_ret;



	ret = clk_prepare_enable(cclk);

	if (ret)

		goto disable_cclk_ret;



	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");

	addr = devm_ioremap_resource(&pdev->dev, res);

	irq = platform_get_irq_byname(pdev, "int0");

	if (IS_ERR(addr) || irq < 0)

		return -EINVAL;



	/* allocate the m_can device */

	dev = alloc_m_can_dev();

	if (!dev)

		return -ENOMEM;

	if (IS_ERR(addr) || irq < 0) {

		ret = -EINVAL;

		goto disable_cclk_ret;

	}



	/* message ram could be shared */

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");

	if (!res) {

		ret = -ENODEV;

		goto disable_cclk_ret;

	}



	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));

	if (!mram_addr) {

		ret = -ENOMEM;

		goto disable_cclk_ret;

	}



	/* get message ram configuration */

	ret = of_property_read_u32_array(np, "bosch,mram-cfg",

					 mram_config_vals,

					 sizeof(mram_config_vals) / 4);

	if (ret) {

		dev_err(&pdev->dev, "Could not get Message RAM configuration.");

		goto disable_cclk_ret;

	}



	/* Get TX FIFO size

	 * Defines the total amount of echo buffers for loopback

	 */

	tx_fifo_size = mram_config_vals[7];



	/* allocate the m_can device */

	dev = alloc_m_can_dev(pdev, addr, tx_fifo_size);

	if (!dev) {

		ret = -ENOMEM;

		goto disable_cclk_ret;

	}

	priv = netdev_priv(dev);

	dev->irq = irq;

	priv->base = addr;

	priv->device = &pdev->dev;

	priv->hclk = hclk;

	priv->cclk = cclk;

	priv->can.clock.freq = clk_get_rate(cclk);

	priv->mram_base = mram_addr;



	ret = m_can_of_parse_mram(pdev, priv);

	if (ret)

		goto failed_free_dev;

	m_can_of_parse_mram(priv, mram_config_vals);



	platform_set_drvdata(pdev, dev);

	SET_NETDEV_DEV(dev, &pdev->dev);
@@ -1291,13 +1481,21 @@ static int m_can_plat_probe(struct platform_device *pdev) 


	devm_can_led_init(dev);



	dev_info(&pdev->dev, "%s device registered (irq=%d)\n",

		 KBUILD_MODNAME, dev->irq);

	dev_info(&pdev->dev, "%s device registered (irq=%d, version=%d)\n",

		 KBUILD_MODNAME, dev->irq, priv->version);



	return 0;

	/* Probe finished

	 * Stop clocks. They will be reactivated once the M_CAN device is opened

	 */

	goto disable_cclk_ret;



failed_free_dev:

	free_m_can_dev(dev);

disable_cclk_ret:

	clk_disable_unprepare(cclk);

disable_hclk_ret:

	clk_disable_unprepare(hclk);

failed_ret:

	return ret;

}

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