Commit 4f7d5851 authored by David S. Miller's avatar David S. Miller

Merge tag 'linux-can-next-for-4.16-20180116' of...

Merge tag 'linux-can-next-for-4.16-20180116' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2018-01-16

this is a pull request for net-next/master consisting of 9 patches.

This is a series of patches, some of them initially by Franklin S Cooper
Jr, which was picked up by Faiz Abbas. Faiz Abbas added some patches
while working on this series, I contributed one as well.

The first two patches add support to CAN device infrastructure to limit
the bitrate of a CAN adapter if the used CAN-transceiver has a certain
maximum bitrate.

The remaining patches improve the m_can driver. They add support for
bitrate limiting to the driver, clean up the driver and add support for
runtime PM.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 5ef7e0ba 31643dc8
Generic CAN transceiver Device Tree binding
------------------------------
CAN transceiver typically limits the max speed in standard CAN and CAN FD
modes. Typically these limitations are static and the transceivers themselves
provide no way to detect this limitation at runtime. For this situation,
the "can-transceiver" node can be used.
Required Properties:
max-bitrate: a positive non 0 value that determines the max
speed that CAN/CAN-FD can run. Any other value
will be ignored.
Examples:
Based on Texas Instrument's TCAN1042HGV CAN Transceiver
m_can0 {
....
can-transceiver {
max-bitrate = <5000000>;
};
...
};
......@@ -43,6 +43,11 @@ Required properties:
Please refer to 2.4.1 Message RAM Configuration in
Bosch M_CAN user manual for details.
Optional Subnode:
- can-transceiver : Can-transceiver subnode describing maximum speed
that can be used for CAN/CAN-FD modes. See
Documentation/devicetree/bindings/net/can/can-transceiver.txt
for details.
Example:
SoC dtsi:
m_can1: can@20e8000 {
......@@ -63,4 +68,8 @@ Board dts:
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_m_can1>;
status = "enabled";
can-transceiver {
max-bitrate = <5000000>;
};
};
......@@ -27,6 +27,7 @@
#include <linux/can/skb.h>
#include <linux/can/netlink.h>
#include <linux/can/led.h>
#include <linux/of.h>
#include <net/rtnetlink.h>
#define MOD_DESC "CAN device driver interface"
......@@ -814,6 +815,29 @@ int open_candev(struct net_device *dev)
}
EXPORT_SYMBOL_GPL(open_candev);
#ifdef CONFIG_OF
/* Common function that can be used to understand the limitation of
* a transceiver when it provides no means to determine these limitations
* at runtime.
*/
void of_can_transceiver(struct net_device *dev)
{
struct device_node *dn;
struct can_priv *priv = netdev_priv(dev);
struct device_node *np = dev->dev.parent->of_node;
int ret;
dn = of_get_child_by_name(np, "can-transceiver");
if (!dn)
return;
ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
}
EXPORT_SYMBOL_GPL(of_can_transceiver);
#endif
/*
* Common close function for cleanup before the device gets closed.
*
......@@ -913,6 +937,13 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
priv->bitrate_const_cnt);
if (err)
return err;
if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
priv->bitrate_max);
return -EINVAL;
}
memcpy(&priv->bittiming, &bt, sizeof(bt));
if (priv->do_set_bittiming) {
......@@ -997,6 +1028,13 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
priv->data_bitrate_const_cnt);
if (err)
return err;
if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
priv->bitrate_max);
return -EINVAL;
}
memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
if (priv->do_set_data_bittiming) {
......@@ -1064,6 +1102,7 @@ static size_t can_get_size(const struct net_device *dev)
if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */
size += nla_total_size(sizeof(*priv->data_bitrate_const) *
priv->data_bitrate_const_cnt);
size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
return size;
}
......@@ -1121,7 +1160,11 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
sizeof(*priv->data_bitrate_const) *
priv->data_bitrate_const_cnt,
priv->data_bitrate_const))
priv->data_bitrate_const)) ||
(nla_put(skb, IFLA_CAN_BITRATE_MAX,
sizeof(priv->bitrate_max),
&priv->bitrate_max))
)
return -EMSGSIZE;
......
......@@ -23,6 +23,7 @@
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/iopoll.h>
#include <linux/can/dev.h>
......@@ -126,6 +127,12 @@ enum m_can_mram_cfg {
#define DBTP_DSJW_SHIFT 0
#define DBTP_DSJW_MASK (0xf << DBTP_DSJW_SHIFT)
/* Transmitter Delay Compensation Register (TDCR) */
#define TDCR_TDCO_SHIFT 8
#define TDCR_TDCO_MASK (0x7F << TDCR_TDCO_SHIFT)
#define TDCR_TDCF_SHIFT 0
#define TDCR_TDCF_MASK (0x7F << TDCR_TDCF_SHIFT)
/* Test Register (TEST) */
#define TEST_LBCK BIT(4)
......@@ -625,21 +632,16 @@ static int m_can_clk_start(struct m_can_priv *priv)
{
int err;
err = clk_prepare_enable(priv->hclk);
err = pm_runtime_get_sync(priv->device);
if (err)
return err;
err = clk_prepare_enable(priv->cclk);
if (err)
clk_disable_unprepare(priv->hclk);
pm_runtime_put_noidle(priv->device);
return err;
}
static void m_can_clk_stop(struct m_can_priv *priv)
{
clk_disable_unprepare(priv->cclk);
clk_disable_unprepare(priv->hclk);
pm_runtime_put_sync(priv->device);
}
static int m_can_get_berr_counter(const struct net_device *dev,
......@@ -987,13 +989,47 @@ static int m_can_set_bittiming(struct net_device *dev)
m_can_write(priv, M_CAN_NBTP, reg_btp);
if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
reg_btp = 0;
brp = dbt->brp - 1;
sjw = dbt->sjw - 1;
tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
tseg2 = dbt->phase_seg2 - 1;
reg_btp = (brp << DBTP_DBRP_SHIFT) | (sjw << DBTP_DSJW_SHIFT) |
/* TDC is only needed for bitrates beyond 2.5 MBit/s.
* This is mentioned in the "Bit Time Requirements for CAN FD"
* paper presented at the International CAN Conference 2013
*/
if (dbt->bitrate > 2500000) {
u32 tdco, ssp;
/* Use the same value of secondary sampling point
* as the data sampling point
*/
ssp = dbt->sample_point;
/* Equation based on Bosch's M_CAN User Manual's
* Transmitter Delay Compensation Section
*/
tdco = (priv->can.clock.freq / 1000) *
ssp / dbt->bitrate;
/* Max valid TDCO value is 127 */
if (tdco > 127) {
netdev_warn(dev, "TDCO value of %u is beyond maximum. Using maximum possible value\n",
tdco);
tdco = 127;
}
reg_btp |= DBTP_TDC;
m_can_write(priv, M_CAN_TDCR,
tdco << TDCR_TDCO_SHIFT);
}
reg_btp |= (brp << DBTP_DBRP_SHIFT) |
(sjw << DBTP_DSJW_SHIFT) |
(tseg1 << DBTP_DTSEG1_SHIFT) |
(tseg2 << DBTP_DTSEG2_SHIFT);
m_can_write(priv, M_CAN_DBTP, reg_btp);
}
......@@ -1143,11 +1179,6 @@ static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
return 0;
}
static void free_m_can_dev(struct net_device *dev)
{
free_candev(dev);
}
/* Checks core release number of M_CAN
* returns 0 if an unsupported device is detected
* else it returns the release and step coded as:
......@@ -1207,31 +1238,20 @@ static bool m_can_niso_supported(const struct m_can_priv *priv)
return !niso_timeout;
}
static struct net_device *alloc_m_can_dev(struct platform_device *pdev,
void __iomem *addr, u32 tx_fifo_size)
static int m_can_dev_setup(struct platform_device *pdev, struct net_device *dev,
void __iomem *addr)
{
struct net_device *dev;
struct m_can_priv *priv;
int m_can_version;
unsigned int echo_buffer_count;
m_can_version = m_can_check_core_release(addr);
/* return if unsupported version */
if (!m_can_version) {
dev = NULL;
goto return_dev;
dev_err(&pdev->dev, "Unsupported version number: %2d",
m_can_version);
return -EINVAL;
}
/* 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);
......@@ -1273,16 +1293,12 @@ static struct net_device *alloc_m_can_dev(struct platform_device *pdev,
: 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 -EINVAL;
}
return_dev:
return dev;
return 0;
}
static int m_can_open(struct net_device *dev)
......@@ -1574,37 +1590,26 @@ static int m_can_plat_probe(struct platform_device *pdev)
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) {
ret = -EINVAL;
goto disable_cclk_ret;
goto failed_ret;
}
/* message ram could be shared */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
if (!res) {
ret = -ENODEV;
goto disable_cclk_ret;
goto failed_ret;
}
mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!mram_addr) {
ret = -ENOMEM;
goto disable_cclk_ret;
goto failed_ret;
}
/* get message ram configuration */
......@@ -1613,7 +1618,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
sizeof(mram_config_vals) / 4);
if (ret) {
dev_err(&pdev->dev, "Could not get Message RAM configuration.");
goto disable_cclk_ret;
goto failed_ret;
}
/* Get TX FIFO size
......@@ -1622,11 +1627,12 @@ static int m_can_plat_probe(struct platform_device *pdev)
tx_fifo_size = mram_config_vals[7];
/* allocate the m_can device */
dev = alloc_m_can_dev(pdev, addr, tx_fifo_size);
dev = alloc_candev(sizeof(*priv), tx_fifo_size);
if (!dev) {
ret = -ENOMEM;
goto disable_cclk_ret;
goto failed_ret;
}
priv = netdev_priv(dev);
dev->irq = irq;
priv->device = &pdev->dev;
......@@ -1640,30 +1646,42 @@ static int m_can_plat_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
/* Enable clocks. Necessary to read Core Release in order to determine
* M_CAN version
*/
pm_runtime_enable(&pdev->dev);
ret = m_can_clk_start(priv);
if (ret)
goto pm_runtime_fail;
ret = m_can_dev_setup(pdev, dev, addr);
if (ret)
goto clk_disable;
ret = register_m_can_dev(dev);
if (ret) {
dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
KBUILD_MODNAME, ret);
goto failed_free_dev;
goto clk_disable;
}
devm_can_led_init(dev);
of_can_transceiver(dev);
dev_info(&pdev->dev, "%s device registered (irq=%d, version=%d)\n",
KBUILD_MODNAME, dev->irq, priv->version);
/* 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);
clk_disable:
m_can_clk_stop(priv);
pm_runtime_fail:
if (ret) {
pm_runtime_disable(&pdev->dev);
free_candev(dev);
}
failed_ret:
return ret;
}
......@@ -1721,14 +1739,47 @@ static int m_can_plat_remove(struct platform_device *pdev)
struct net_device *dev = platform_get_drvdata(pdev);
unregister_m_can_dev(dev);
pm_runtime_disable(&pdev->dev);
platform_set_drvdata(pdev, NULL);
free_m_can_dev(dev);
free_candev(dev);
return 0;
}
static int m_can_runtime_suspend(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct m_can_priv *priv = netdev_priv(ndev);
clk_disable_unprepare(priv->cclk);
clk_disable_unprepare(priv->hclk);
return 0;
}
static int m_can_runtime_resume(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct m_can_priv *priv = netdev_priv(ndev);
int err;
err = clk_prepare_enable(priv->hclk);
if (err)
return err;
err = clk_prepare_enable(priv->cclk);
if (err)
clk_disable_unprepare(priv->hclk);
return err;
}
static const struct dev_pm_ops m_can_pmops = {
SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
m_can_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
};
......
......@@ -46,6 +46,7 @@ struct can_priv {
unsigned int bitrate_const_cnt;
const u32 *data_bitrate_const;
unsigned int data_bitrate_const_cnt;
u32 bitrate_max;
struct can_clock clock;
enum can_state state;
......@@ -166,6 +167,12 @@ void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
void can_free_echo_skb(struct net_device *dev, unsigned int idx);
#ifdef CONFIG_OF
void of_can_transceiver(struct net_device *dev);
#else
static inline void of_can_transceiver(struct net_device *dev) { }
#endif
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
struct sk_buff *alloc_canfd_skb(struct net_device *dev,
struct canfd_frame **cfd);
......
......@@ -132,6 +132,7 @@ enum {
IFLA_CAN_TERMINATION_CONST,
IFLA_CAN_BITRATE_CONST,
IFLA_CAN_DATA_BITRATE_CONST,
IFLA_CAN_BITRATE_MAX,
__IFLA_CAN_MAX
};
......
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