phy: add Broadcom SATA3 PHY driver for Broadcom STB SoCs

Supports up to two ports which can each be powered on/off and configured
independently.

Signed-off-by: Brian Norris <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

drivers/phy/Kconfig

···
 	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

drivers/phy/Makefile

···
 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

drivers/phy/phy-brcmstb-sata.c

···
+/*
+ * 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 {
+	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 brcm_sata_cfg_ssc_28nm(struct brcm_sata_port *port)
+{
+	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);
+
+	brcm_sata_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);
+
+	return 0;
+}
+
+static struct platform_driver brcm_sata_phy_driver = {
+	.probe	= brcm_sata_phy_probe,
+	.driver	= {
+		.of_match_table	= brcm_sata_phy_of_match,
+		.name		= "brcmstb-sata-phy",
+	}
+};
+module_platform_driver(brcm_sata_phy_driver);
+
+MODULE_DESCRIPTION("Broadcom STB SATA PHY driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marc Carino");
+MODULE_AUTHOR("Brian Norris");
+MODULE_ALIAS("platform:phy-brcmstb-sata");