Re: [PATCH v3 4/5] phy: add Broadcom SATA3 PHY driver for Broadcom STB SoCs

[Brian Norris <computersforpeace@gmail.com>]

On Wed, May 13, 2015 at 04:37:05PM +0530, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On Wednesday 13 May 2015 04:58 AM, Brian Norris wrote:
> >Supports up to two ports which can each be powered on/off and configured
> >independently.
> >
> >Signed-off-by: Brian Norris <computersforpeace@gmail.com>
> 
> couple of minor comments below
> >---
> >v3: no change
> >
> >v2:
> >   - stop sharing SATA_TOP_CTRL registers with SATA driver
> >   - kill custom xlate function
> >
> >  drivers/phy/Kconfig            |   9 ++
> >  drivers/phy/Makefile           |   1 +
> >  drivers/phy/phy-brcmstb-sata.c | 216 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 226 insertions(+)
> >  create mode 100644 drivers/phy/phy-brcmstb-sata.c
> >
> >diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> >index a53bd5b52df9..36788b6f0220 100644
> >--- a/drivers/phy/Kconfig
> >+++ b/drivers/phy/Kconfig
> >@@ -309,4 +309,13 @@ config PHY_QCOM_UFS
> >  	help
> >  	  Support for UFS PHY on QCOM chipsets.
> >
> >+config PHY_BRCMSTB_SATA
> >+	tristate "Broadcom STB SATA PHY driver"
> >+	depends on ARCH_BRCMSTB
> >+	depends on OF
> >+	select GENERIC_PHY
> >+	help
> >+	  Enable this to support the SATA3 PHY on 28nm Broadcom STB SoCs.
> >+	  Likely useful only with CONFIG_SATA_BRCMSTB enabled.
> >+
> >  endmenu
> >diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> >index f12625178780..c61f3fdd191e 100644
> >--- a/drivers/phy/Makefile
> >+++ b/drivers/phy/Makefile
> >@@ -40,3 +40,4 @@ obj-$(CONFIG_PHY_STIH41X_USB)		+= phy-stih41x-usb.o
> >  obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs.o
> >  obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs-qmp-20nm.o
> >  obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs-qmp-14nm.o
> >+obj-$(CONFIG_PHY_BRCMSTB_SATA)		+= phy-brcmstb-sata.o
> >diff --git a/drivers/phy/phy-brcmstb-sata.c b/drivers/phy/phy-brcmstb-sata.c
> >new file mode 100644
> >index 000000000000..8387c8cbea8c
> >--- /dev/null
> >+++ b/drivers/phy/phy-brcmstb-sata.c
> >@@ -0,0 +1,216 @@
> >+/*
> >+ * Broadcom SATA3 AHCI Controller PHY Driver
> >+ *
> >+ * Copyright © 2009-2015 Broadcom Corporation
> >+ *
> >+ * This program is free software; you can redistribute it and/or modify
> >+ * it under the terms of the GNU General Public License as published by
> >+ * the Free Software Foundation; either version 2, or (at your option)
> >+ * any later version.
> >+ *
> >+ * This program is distributed in the hope that it will be useful,
> >+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >+ * GNU General Public License for more details.
> >+ */
> >+
> >+#include <linux/device.h>
> >+#include <linux/init.h>
> >+#include <linux/interrupt.h>
> >+#include <linux/io.h>
> >+#include <linux/kernel.h>
> >+#include <linux/module.h>
> >+#include <linux/of.h>
> >+#include <linux/phy/phy.h>
> >+#include <linux/platform_device.h>
> >+
> >+#define SATA_MDIO_BANK_OFFSET				0x23c
> >+#define SATA_MDIO_REG_OFFSET(ofs)			((ofs) * 4)
> >+#define SATA_MDIO_REG_SPACE_SIZE			0x1000
> >+#define SATA_MDIO_REG_LENGTH				0x1f00
> >+
> >+#define MAX_PORTS					2
> >+
> >+/* Register offset between PHYs in PCB space */
> >+#define SATA_MDIO_REG_SPACE_SIZE			0x1000
> >+
> >+struct brcm_sata_port {
> >+	int portnum;
> >+	struct phy *phy;
> >+	struct brcm_sata_phy *phy_priv;
> >+	bool ssc_en;
> >+};
> >+
> >+struct brcm_sata_phy {
> >+	struct device *dev;
> >+	void __iomem *phy_base;
> >+
> >+	struct brcm_sata_port phys[MAX_PORTS];
> >+};
> >+
> >+enum sata_mdio_phy_regs_28nm {
> 
> Why should these defines be in enum?

Why not? They're logically grouped this way, and IMO, they look nicer.
You can see drivers/ata/ahci.h for a similar example.

> >+	PLL_REG_BANK_0				= 0x50,
> >+	PLL_REG_BANK_0_PLLCONTROL_0		= 0x81,
> >+
> >+	TXPMD_REG_BANK				= 0x1a0,
> >+	TXPMD_CONTROL1				= 0x81,
> >+	TXPMD_CONTROL1_TX_SSC_EN_FRC		= BIT(0),
> >+	TXPMD_CONTROL1_TX_SSC_EN_FRC_VAL	= BIT(1),
> >+	TXPMD_TX_FREQ_CTRL_CONTROL1		= 0x82,
> >+	TXPMD_TX_FREQ_CTRL_CONTROL2		= 0x83,
> >+	TXPMD_TX_FREQ_CTRL_CONTROL2_FMIN_MASK	= 0x3ff,
> >+	TXPMD_TX_FREQ_CTRL_CONTROL3		= 0x84,
> >+	TXPMD_TX_FREQ_CTRL_CONTROL3_FMAX_MASK	= 0x3ff,
> >+};
> >+
> >+static inline void __iomem *brcm_sata_phy_base(struct brcm_sata_port *port)
> >+{
> >+	struct brcm_sata_phy *priv = port->phy_priv;
> >+
> >+	return priv->phy_base + (port->portnum * SATA_MDIO_REG_SPACE_SIZE);
> >+}
> >+
> >+static void brcm_sata_mdio_wr(void __iomem *addr, u32 bank, u32 ofs,
> >+			      u32 msk, u32 value)
> >+{
> >+	u32 tmp;
> >+
> >+	writel(bank, addr + SATA_MDIO_BANK_OFFSET);
> >+	tmp = readl(addr + SATA_MDIO_REG_OFFSET(ofs));
> >+	tmp = (tmp & msk) | value;
> >+	writel(tmp, addr + SATA_MDIO_REG_OFFSET(ofs));
> >+}
> >+
> >+/* These defaults were characterized by H/W group */
> >+#define FMIN_VAL_DEFAULT	0x3df
> >+#define FMAX_VAL_DEFAULT	0x3df
> >+#define FMAX_VAL_SSC		0x83
> >+
> >+static void cfg_ssc_28nm(struct brcm_sata_port *port)
> 
> brcm_sata_cfg_ssc_28nm to make it similar to other functions.

OK.

> >+{
> >+	void __iomem *base = brcm_sata_phy_base(port);
> >+	struct brcm_sata_phy *priv = port->phy_priv;
> >+	u32 tmp;
> >+
> >+	/* override the TX spread spectrum setting */
> >+	tmp = TXPMD_CONTROL1_TX_SSC_EN_FRC_VAL | TXPMD_CONTROL1_TX_SSC_EN_FRC;
> >+	brcm_sata_mdio_wr(base, TXPMD_REG_BANK, TXPMD_CONTROL1, ~tmp, tmp);
> >+
> >+	/* set fixed min freq */
> >+	brcm_sata_mdio_wr(base, TXPMD_REG_BANK, TXPMD_TX_FREQ_CTRL_CONTROL2,
> >+			  ~TXPMD_TX_FREQ_CTRL_CONTROL2_FMIN_MASK,
> >+			  FMIN_VAL_DEFAULT);
> >+
> >+	/* set fixed max freq depending on SSC config */
> >+	if (port->ssc_en) {
> >+		dev_info(priv->dev, "enabling SSC on port %d\n", port->portnum);
> >+		tmp = FMAX_VAL_SSC;
> >+	} else {
> >+		tmp = FMAX_VAL_DEFAULT;
> >+	}
> >+
> >+	brcm_sata_mdio_wr(base, TXPMD_REG_BANK, TXPMD_TX_FREQ_CTRL_CONTROL3,
> >+			  ~TXPMD_TX_FREQ_CTRL_CONTROL3_FMAX_MASK, tmp);
> >+}
> >+
> >+static int brcm_sata_phy_init(struct phy *phy)
> >+{
> >+	struct brcm_sata_port *port = phy_get_drvdata(phy);
> >+
> >+	cfg_ssc_28nm(port);
> >+
> >+	return 0;
> >+}
> >+
> >+static struct phy_ops phy_ops_28nm = {
> >+	.init		= brcm_sata_phy_init,
> >+	.owner		= THIS_MODULE,
> >+};
> >+
> >+static const struct of_device_id brcm_sata_phy_of_match[] = {
> >+	{ .compatible	= "brcm,bcm7445-sata-phy" },
> >+	{},
> >+};
> >+MODULE_DEVICE_TABLE(of, brcm_sata_phy_of_match);
> >+
> >+static int brcm_sata_phy_probe(struct platform_device *pdev)
> >+{
> >+	struct device *dev = &pdev->dev;
> >+	struct device_node *dn = dev->of_node, *child;
> >+	struct brcm_sata_phy *priv;
> >+	struct resource *res;
> >+	struct phy_provider *provider;
> >+	int count = 0;
> >+
> >+	if (of_get_child_count(dn) == 0)
> >+		return -ENODEV;
> >+
> >+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> >+	if (!priv)
> >+		return -ENOMEM;
> >+	dev_set_drvdata(dev, priv);
> >+	priv->dev = dev;
> >+
> >+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
> >+	priv->phy_base = devm_ioremap_resource(dev, res);
> >+	if (IS_ERR(priv->phy_base))
> >+		return PTR_ERR(priv->phy_base);
> >+
> >+	for_each_available_child_of_node(dn, child) {
> >+		unsigned int id;
> >+		struct brcm_sata_port *port;
> >+
> >+		if (of_property_read_u32(child, "reg", &id)) {
> >+			dev_err(dev, "missing reg property in node %s\n",
> >+					child->name);
> >+			return -EINVAL;
> >+		}
> >+
> >+		if (id >= MAX_PORTS) {
> >+			dev_err(dev, "invalid reg: %u\n", id);
> >+			return -EINVAL;
> >+		}
> >+		if (priv->phys[id].phy) {
> >+			dev_err(dev, "already registered port %u\n", id);
> >+			return -EINVAL;
> >+		}
> >+
> >+		port = &priv->phys[id];
> >+		port->portnum = id;
> >+		port->phy_priv = priv;
> >+		port->phy = devm_phy_create(dev, child, &phy_ops_28nm);
> >+		port->ssc_en = of_property_read_bool(child, "brcm,enable-ssc");
> >+		if (IS_ERR(port->phy)) {
> >+			dev_err(dev, "failed to create PHY\n");
> >+			return PTR_ERR(port->phy);
> >+		}
> >+
> >+		phy_set_drvdata(port->phy, port);
> >+		count++;
> >+	}
> >+
> >+	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> >+	if (IS_ERR(provider)) {
> >+		dev_err(dev, "could not register PHY provider\n");
> >+		return PTR_ERR(provider);
> >+	}
> >+
> >+	dev_info(dev, "registered %d port(s)\n", count);
> 
> lets not make the boot noisy. Change to dev_dbg?

Why? What's the harm? And I thought we discussed this already. "Noisy"
depends on your point of view; IMO, this is important information. If
for some reason this driver wasn't loaded or probed, we'd want to know.
Besides, dev_dbg() requires you to fiddle with both the log level and
the dynamic debug boot parameters just to get these informational
messages.

Brian