Thread (11 messages) 11 messages, 5 authors, 2019-05-19

Re: [PATCH v3 3/3] net: ethernet: add ag71xx driver

From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2019-05-19 17:35:28
Also in: linux-devicetree, linux-mips, lkml

Hi Andrew,

thank you for the review!

On Mon, Apr 22, 2019 at 03:25:33PM +0200, Andrew Lunn wrote:
On Mon, Apr 22, 2019 at 08:40:46AM +0200, Oleksij Rempel wrote:
quoted
+static int ag71xx_msg_enable = -1;
+
+module_param_named(msg_enable, ag71xx_msg_enable, uint,
+		   (S_IRUSR|S_IRGRP|S_IROTH));
+MODULE_PARM_DESC(msg_enable, "Debug message level (see linux/netdevice.h for bitmap)");
Hi Oleksij

Module parameters are generally not liked.

Please use .set_msglevel.
Ok, I remove it for now. ethtool ops are currently not supported in this
driver.
quoted
+static int ag71xx_mdio_mii_read(struct mii_bus *bus, int addr, int reg)
+{
+	struct ag71xx *ag = bus->priv;
+	struct net_device *ndev = ag->ndev;
+	int err;
+	int ret;
+
+	err = ag71xx_mdio_wait_busy(ag);
+	if (err)
+		return 0xffff;
+
+	ag71xx_wr(ag, AG71XX_REG_MII_CMD, MII_CMD_WRITE);
It would be good to comment why you need this. Or is it a copy/paste
error?
copy/paste. fixed.
quoted
+	ag71xx_wr(ag, AG71XX_REG_MII_ADDR,
+			((addr & 0xff) << MII_ADDR_SHIFT) | (reg & 0xff));
+	ag71xx_wr(ag, AG71XX_REG_MII_CMD, MII_CMD_READ);
+
+	err = ag71xx_mdio_wait_busy(ag);
+	if (err)
+		return 0xffff;
+
+	ret = ag71xx_rr(ag, AG71XX_REG_MII_STATUS);
+	ret &= 0xffff;
+	ag71xx_wr(ag, AG71XX_REG_MII_CMD, MII_CMD_WRITE);
This one as well.
done
quoted
+
+	netif_dbg(ag, link, ndev, "mii_read: addr=%04x, reg=%04x, value=%04x\n",
+		  addr, reg, ret);
+
+	return ret;
+}
+
+static int ag71xx_mdio_mii_write(struct mii_bus *bus, int addr, int reg,
+				 u16 val)
+{
+	struct ag71xx *ag = bus->priv;
+	struct net_device *ndev = ag->ndev;
+
+	netif_dbg(ag, link, ndev, "mii_write: addr=%04x, reg=%04x, value=%04x\n",
+		  addr, reg, val);
+
+	ag71xx_wr(ag, AG71XX_REG_MII_ADDR,
+			((addr & 0xff) << MII_ADDR_SHIFT) | (reg & 0xff));
+	ag71xx_wr(ag, AG71XX_REG_MII_CTRL, val);
+
+	ag71xx_mdio_wait_busy(ag);
+
+	return 0;
Return the -ETIMEOUT from ag71xx_mdio_wait_busy() please.
done
quoted
+static int ag71xx_mdio_get_divider(struct ag71xx *ag, u32 *div)
+{
+	struct device *dev = &ag->pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct clk *ref_clk = of_clk_get(np, 0);
+	unsigned long ref_clock;
+	const u32 *table;
+	int ndivs, i;
+
+	if (IS_ERR(ref_clk))
+		return -EINVAL;
+
+	ref_clock = clk_get_rate(ref_clk);
I _think_ you need to prepare and enable the clock before you can use
clk_get_rate().
This WiSoC has no advanced clk infrastructure. Almost every thing is
connected to AHB clock and can't be enabled or disabled. Any way, I added
proper clk registration in case there are more modern variants..
quoted
+	clk_put(ref_clk);
+
+	if (ag71xx_is(ag, AR9330) || ag71xx_is(ag, AR9340)) {
+		table = ar933x_mdio_div_table;
+		ndivs = ARRAY_SIZE(ar933x_mdio_div_table);
+	} else if (ag71xx_is(ag, AR7240)) {
+		table = ar7240_mdio_div_table;
+		ndivs = ARRAY_SIZE(ar7240_mdio_div_table);
+	} else {
+		table = ar71xx_mdio_div_table;
+		ndivs = ARRAY_SIZE(ar71xx_mdio_div_table);
+	}
+
+	for (i = 0; i < ndivs; i++) {
+		unsigned long t;
+
+		t = ref_clock / table[i];
+		if (t <= AG71XX_MDIO_MAX_CLK) {
+			*div = i;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+static int ag71xx_mdio_reset(struct mii_bus *bus)
+{
+	struct ag71xx *ag = bus->priv;
+	u32 t;
+
+	if (ag71xx_mdio_get_divider(ag, &t)) {
+		if (ag71xx_is(ag, AR9340))
+			t = MII_CFG_CLK_DIV_58;
+		else
+			t = MII_CFG_CLK_DIV_10;
+	}
You should return the -ENOENT from ag71xx_mdio_get_divider().
done. 
quoted
+
+	ag71xx_wr(ag, AG71XX_REG_MII_CFG, t | MII_CFG_RESET);
+	udelay(100);
+
+	ag71xx_wr(ag, AG71XX_REG_MII_CFG, t);
+	udelay(100);
+
+	return 0;
+}
+
+static int ag71xx_mdio_probe(struct ag71xx *ag)
+{
+	static struct mii_bus *mii_bus;
+	struct device *dev = &ag->pdev->dev;
+	struct device_node *np = dev->of_node;
+	int err;
+
+	ag->mii_bus = NULL;
+
+	/*
+	 * On most (all?) Atheros/QCA SoCs dual eth interfaces are not equal.
+	 *
+	 * That is to say eth0 can not work independently. It only works
+	 * when eth1 is working.
+	 */
Please could you explain that some more? Is there just one MDIO bus
shared by two ethernet controllers? If so, it would be better to have
the MDIO bus controller as a separate driver.
hm... I compared different Atheros/QCA docs and noticed that it is a
wrong statement. All of them have MDIO for each ETH. In case of
AR9331 MDIO0 is not connected to the internal switch/phy. Not sure if it
is connected to any thing at all.

I'll remove this quirk.
quoted
+	if ((ag->dcfg->quirks & AG71XX_ETH0_NO_MDIO) && !ag->mac_idx)
+		return 0;
+
+	mii_bus = devm_mdiobus_alloc(dev);
+	if (!mii_bus)
+		return -ENOMEM;
+
+	ag->mdio_reset = of_reset_control_get_exclusive(np, "mdio");
Can this return -EPROBE_DEFFER? If so, you should return it.
done
quoted
+
+	mii_bus->name = "ag71xx_mdio";
+	mii_bus->read = ag71xx_mdio_mii_read;
+	mii_bus->write = ag71xx_mdio_mii_write;
+	mii_bus->reset = ag71xx_mdio_reset;
+	mii_bus->priv = ag;
+	mii_bus->parent = dev;
+	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s.%d", np->name, ag->mac_idx);
+
+	if (!IS_ERR(ag->mdio_reset)) {
+		reset_control_assert(ag->mdio_reset);
+		msleep(100);
+		reset_control_deassert(ag->mdio_reset);
+		msleep(200);
+	}
+
+	err = of_mdiobus_register(mii_bus, np);
+	if (err)
+		return err;
+
+	ag->mii_bus = mii_bus;
+
+	return 0;
+}
quoted
+static void ag71xx_dma_reset(struct ag71xx *ag)
+{
+	u32 val;
+	int i;
+
+
+	/* stop RX and TX */
+	ag71xx_wr(ag, AG71XX_REG_RX_CTRL, 0);
+	ag71xx_wr(ag, AG71XX_REG_TX_CTRL, 0);
+
+	/*
+	 * give the hardware some time to really stop all rx/tx activity
+	 * clearing the descriptors too early causes random memory corruption
+	 */
+	mdelay(1);
This does not sounds too safe. Can you walk the descriptor rings to
know it has finished?
good point. done.
quoted
+static unsigned char *ag71xx_speed_str(struct ag71xx *ag)
+{
+	switch (ag->speed) {
+	case SPEED_1000:
+		return "1000";
+	case SPEED_100:
+		return "100";
+	case SPEED_10:
+		return "10";
+	}
+
+	return "?";
+}
phy_speed_to_str()
done
quoted
+
+static void ag71xx_link_adjust(struct ag71xx *ag, bool update)
+{
+	struct net_device *ndev = ag->ndev;
+	u32 cfg2;
+	u32 ifctl;
+	u32 fifo5;
+
+	if (!ag->link && update) {
+		ag71xx_hw_stop(ag);
+		netif_carrier_off(ag->ndev);
+		netif_info(ag, link, ndev, "link down\n");
+		return;
+	}
+
+	if (!ag71xx_is(ag, AR7100) && !ag71xx_is(ag, AR9130))
+		ag71xx_fast_reset(ag);
+
+	cfg2 = ag71xx_rr(ag, AG71XX_REG_MAC_CFG2);
+	cfg2 &= ~(MAC_CFG2_IF_1000 | MAC_CFG2_IF_10_100 | MAC_CFG2_FDX);
+	cfg2 |= (ag->duplex) ? MAC_CFG2_FDX : 0;
+
+	ifctl = ag71xx_rr(ag, AG71XX_REG_MAC_IFCTL);
+	ifctl &= ~(MAC_IFCTL_SPEED);
+
+	fifo5 = ag71xx_rr(ag, AG71XX_REG_FIFO_CFG5);
+	fifo5 &= ~FIFO_CFG5_BM;
+
+	switch (ag->speed) {
+	case SPEED_1000:
+		cfg2 |= MAC_CFG2_IF_1000;
+		fifo5 |= FIFO_CFG5_BM;
+		break;
+	case SPEED_100:
+		cfg2 |= MAC_CFG2_IF_10_100;
+		ifctl |= MAC_IFCTL_SPEED;
+		break;
+	case SPEED_10:
+		cfg2 |= MAC_CFG2_IF_10_100;
+		break;
+	default:
+		BUG();
Please don't use BUG(). That kills the machine. WARN().
done
quoted
+		return;
+	}
+
+	if (ag->tx_ring.desc_split) {
+		ag->fifodata[2] &= 0xffff;
+		ag->fifodata[2] |= ((2048 - ag->tx_ring.desc_split) / 4) << 16;
+	}
+
+	ag71xx_wr(ag, AG71XX_REG_FIFO_CFG3, ag->fifodata[2]);
+
+	ag71xx_wr(ag, AG71XX_REG_MAC_CFG2, cfg2);
+	ag71xx_wr(ag, AG71XX_REG_FIFO_CFG5, fifo5);
+	ag71xx_wr(ag, AG71XX_REG_MAC_IFCTL, ifctl);
+
+	ag71xx_hw_start(ag);
+
+	netif_carrier_on(ag->ndev);
You should not need to do anything with the carrier. phylib will do
all that for you.
done
quoted
+	if (update)
+		netif_info(ag, link, ndev, "link up (%sMbps/%s duplex)\n",
+			   ag71xx_speed_str(ag),
+			   (DUPLEX_FULL == ag->duplex) ? "Full" : "Half");
phy_print_status() is the standard way to do this.
done
quoted
+}
+
+static void ag71xx_phy_link_adjust(struct net_device *ndev)
+{
+	struct ag71xx *ag = netdev_priv(ndev);
+	struct phy_device *phydev = ag->phy_dev;
+	unsigned long flags;
+	int status_change = 0;
+
+	spin_lock_irqsave(&ag->lock, flags);
+
+	if (phydev->link) {
+		if (ag->duplex != phydev->duplex
+		    || ag->speed != phydev->speed) {
+			status_change = 1;
+		}
+	}
+
+	if (phydev->link != ag->link)
+		status_change = 1;
+
+	ag->link = phydev->link;
+	ag->duplex = phydev->duplex;
+	ag->speed = phydev->speed;
It appears you always have some sort of PHY attached, either a real
PHY, or a fixed link. So you can probably simply this, remove
ap->link, ap->dupex, ap->speed, and just get it from phydev when you
need it.
done
quoted
+
+	if (status_change)
+		ag71xx_link_adjust(ag, true);
+
+	spin_unlock_irqrestore(&ag->lock, flags);
You are doing a lot of stuff while holding this spinlock. What exactly
are you protecting?
can't identify it. seems to be artifact from old driver.
quoted
+}
+
+static int ag71xx_phy_connect(struct ag71xx *ag)
+{
+	struct device_node *np = ag->pdev->dev.of_node;
+	struct net_device *ndev = ag->ndev;
+	struct device_node *phy_node;
+	int ret;
+
+	if (of_phy_is_fixed_link(np)) {
+		ret = of_phy_register_fixed_link(np);
+		if (ret < 0) {
+			netif_err(ag, probe, ndev, "Failed to register fixed PHY link: %d\n",
+				  ret);
+			return ret;
+		}
+
+		phy_node = of_node_get(np);
+	} else {
+		phy_node = of_parse_phandle(np, "phy-handle", 0);
+	}
+
+	if (!phy_node) {
+		netif_err(ag, probe, ndev, "Could not find valid phy node\n");
+		return -ENODEV;
+	}
+
+	ag->phy_dev = of_phy_connect(ag->ndev, phy_node, ag71xx_phy_link_adjust,
+				     0, ag->phy_if_mode);
ndev->phydev. No need to place it in the private structure.
done
quoted
+
+	of_node_put(phy_node);
+
+	if (!ag->phy_dev) {
+		netif_err(ag, probe, ndev, "Could not connect to PHY device\n");
+		return -ENODEV;
+	}
+
+	phy_attached_info(ag->phy_dev);
+
+	return 0;
+}
+
+static int ag71xx_open(struct net_device *ndev)
+{
+	struct ag71xx *ag = netdev_priv(ndev);
+	unsigned int max_frame_len;
+	int ret;
+
+	netif_carrier_off(ndev);
+	max_frame_len = ag71xx_max_frame_len(ndev->mtu);
+	ag->rx_buf_size = SKB_DATA_ALIGN(max_frame_len + NET_SKB_PAD + NET_IP_ALIGN);
+
+	/* setup max frame length */
+	ag71xx_wr(ag, AG71XX_REG_MAC_MFL, max_frame_len);
+	ag71xx_hw_set_macaddr(ag, ndev->dev_addr);
+
+	ret = ag71xx_hw_enable(ag);
+	if (ret)
+		goto err;
+
+	ret = ag71xx_phy_connect(ag);
+	if (ret)
+		goto err;
+
+	phy_start(ag->phy_dev);
+
+	return 0;
+
+err:
+	ag71xx_rings_cleanup(ag);
+	return ret;
+}
+
+static int ag71xx_stop(struct net_device *ndev)
+{
+	struct ag71xx *ag = netdev_priv(ndev);
+
+	phy_stop(ag->phy_dev);
+	ag71xx_hw_disable(ag);
+
open() does the phy_connect, so close should do the phy_disconnect.
done
 
quoted
+	return 0;
+}
+
+static int ag71xx_do_ioctl(struct net_device *ndev, struct ifreq *ifr, int cmd)
+{
+	struct ag71xx *ag = netdev_priv(ndev);
+
+	switch (cmd) {
+	case SIOCSIFHWADDR:
+		if (copy_from_user
+			(ndev->dev_addr, ifr->ifr_data, sizeof(ndev->dev_addr)))
+			return -EFAULT;
+		return 0;
+
+	case SIOCGIFHWADDR:
+		if (copy_to_user
+			(ifr->ifr_data, ndev->dev_addr, sizeof(ndev->dev_addr)))
+			return -EFAULT;
+		return 0;
The core code should handle this for you, dev_ifsioc_locked().
done
 
quoted
+
+	case SIOCGMIIPHY:
+	case SIOCGMIIREG:
+	case SIOCSMIIREG:
+		if (ag->phy_dev == NULL)
+			break;
It is more normal to just do

        if (ndev->phydev)
                return phy_mii_ioctl(ndev->phydev, req, cmd);

Out side of the switch statement.
done
quoted
+
+		return phy_mii_ioctl(ag->phy_dev, ifr, cmd);
+
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+}
+
  Andrew
thx!



-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help