diff options
author | Vivek Gautam <vivek.gautam@codeaurora.org> | 2017-04-06 11:21:23 +0530 |
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committer | Kishon Vijay Abraham I <kishon@ti.com> | 2017-04-10 16:43:41 +0530 |
commit | ca04d9d3e1b141f8aeca434c30f876aadf0b5fbf (patch) | |
tree | e2b5f51478b78fde0c0f02ed35fd1bad3dc3d946 /drivers/phy/phy-qcom-qusb2.c | |
parent | e9eef1e596072baa6fba791b110855988a110349 (diff) |
phy: qcom-qusb2: New driver for QUSB2 PHY on Qcom chips
PHY transceiver driver for QUSB2 phy controller that provides
HighSpeed functionality for DWC3 controller present on
Qualcomm chipsets.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Diffstat (limited to 'drivers/phy/phy-qcom-qusb2.c')
-rw-r--r-- | drivers/phy/phy-qcom-qusb2.c | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/drivers/phy/phy-qcom-qusb2.c b/drivers/phy/phy-qcom-qusb2.c new file mode 100644 index 000000000000..6c575244c0fb --- /dev/null +++ b/drivers/phy/phy-qcom-qusb2.c @@ -0,0 +1,493 @@ +/* + * Copyright (c) 2017, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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/clk.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/nvmem-consumer.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/reset.h> +#include <linux/slab.h> + +#define QUSB2PHY_PLL_TEST 0x04 +#define CLK_REF_SEL BIT(7) + +#define QUSB2PHY_PLL_TUNE 0x08 +#define QUSB2PHY_PLL_USER_CTL1 0x0c +#define QUSB2PHY_PLL_USER_CTL2 0x10 +#define QUSB2PHY_PLL_AUTOPGM_CTL1 0x1c +#define QUSB2PHY_PLL_PWR_CTRL 0x18 + +#define QUSB2PHY_PLL_STATUS 0x38 +#define PLL_LOCKED BIT(5) + +#define QUSB2PHY_PORT_TUNE1 0x80 +#define QUSB2PHY_PORT_TUNE2 0x84 +#define QUSB2PHY_PORT_TUNE3 0x88 +#define QUSB2PHY_PORT_TUNE4 0x8c +#define QUSB2PHY_PORT_TUNE5 0x90 +#define QUSB2PHY_PORT_TEST2 0x9c + +#define QUSB2PHY_PORT_POWERDOWN 0xb4 +#define CLAMP_N_EN BIT(5) +#define FREEZIO_N BIT(1) +#define POWER_DOWN BIT(0) + +#define QUSB2PHY_REFCLK_ENABLE BIT(0) + +#define PHY_CLK_SCHEME_SEL BIT(0) + +struct qusb2_phy_init_tbl { + unsigned int offset; + unsigned int val; +}; + +#define QUSB2_PHY_INIT_CFG(o, v) \ + { \ + .offset = o, \ + .val = v, \ + } + +static const struct qusb2_phy_init_tbl msm8996_init_tbl[] = { + QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE1, 0xf8), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE2, 0xb3), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE3, 0x83), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE4, 0xc0), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_TUNE, 0x30), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_USER_CTL1, 0x79), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_USER_CTL2, 0x21), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TEST2, 0x14), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_AUTOPGM_CTL1, 0x9f), + QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_PWR_CTRL, 0x00), +}; + +struct qusb2_phy_cfg { + const struct qusb2_phy_init_tbl *tbl; + /* number of entries in the table */ + unsigned int tbl_num; + /* offset to PHY_CLK_SCHEME register in TCSR map */ + unsigned int clk_scheme_offset; +}; + +static const struct qusb2_phy_cfg msm8996_phy_cfg = { + .tbl = msm8996_init_tbl, + .tbl_num = ARRAY_SIZE(msm8996_init_tbl), +}; + +static const char * const qusb2_phy_vreg_names[] = { + "vdda-pll", "vdda-phy-dpdm", +}; + +#define QUSB2_NUM_VREGS ARRAY_SIZE(qusb2_phy_vreg_names) + +/** + * struct qusb2_phy - structure holding qusb2 phy attributes + * + * @phy: generic phy + * @base: iomapped memory space for qubs2 phy + * + * @cfg_ahb_clk: AHB2PHY interface clock + * @ref_clk: phy reference clock + * @iface_clk: phy interface clock + * @phy_reset: phy reset control + * @vregs: regulator supplies bulk data + * + * @tcsr: TCSR syscon register map + * @cell: nvmem cell containing phy tuning value + * + * @cfg: phy config data + * @has_se_clk_scheme: indicate if PHY has single-ended ref clock scheme + */ +struct qusb2_phy { + struct phy *phy; + void __iomem *base; + + struct clk *cfg_ahb_clk; + struct clk *ref_clk; + struct clk *iface_clk; + struct reset_control *phy_reset; + struct regulator_bulk_data vregs[QUSB2_NUM_VREGS]; + + struct regmap *tcsr; + struct nvmem_cell *cell; + + const struct qusb2_phy_cfg *cfg; + bool has_se_clk_scheme; +}; + +static inline void qusb2_setbits(void __iomem *base, u32 offset, u32 val) +{ + u32 reg; + + reg = readl(base + offset); + reg |= val; + writel(reg, base + offset); + + /* Ensure above write is completed */ + readl(base + offset); +} + +static inline void qusb2_clrbits(void __iomem *base, u32 offset, u32 val) +{ + u32 reg; + + reg = readl(base + offset); + reg &= ~val; + writel(reg, base + offset); + + /* Ensure above write is completed */ + readl(base + offset); +} + +static inline +void qcom_qusb2_phy_configure(void __iomem *base, + const struct qusb2_phy_init_tbl tbl[], int num) +{ + int i; + + for (i = 0; i < num; i++) + writel(tbl[i].val, base + tbl[i].offset); +} + +/* + * Fetches HS Tx tuning value from nvmem and sets the + * QUSB2PHY_PORT_TUNE2 register. + * For error case, skip setting the value and use the default value. + */ +static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy) +{ + struct device *dev = &qphy->phy->dev; + u8 *val; + + /* + * Read efuse register having TUNE2 parameter's high nibble. + * If efuse register shows value as 0x0, or if we fail to find + * a valid efuse register settings, then use default value + * as 0xB for high nibble that we have already set while + * configuring phy. + */ + val = nvmem_cell_read(qphy->cell, NULL); + if (IS_ERR(val) || !val[0]) { + dev_dbg(dev, "failed to read a valid hs-tx trim value\n"); + return; + } + + /* Fused TUNE2 value is the higher nibble only */ + qusb2_setbits(qphy->base, QUSB2PHY_PORT_TUNE2, val[0] << 0x4); +} + +static int qusb2_phy_poweron(struct phy *phy) +{ + struct qusb2_phy *qphy = phy_get_drvdata(phy); + int num = ARRAY_SIZE(qphy->vregs); + int ret; + + dev_vdbg(&phy->dev, "%s(): Powering-on QUSB2 phy\n", __func__); + + /* turn on regulator supplies */ + ret = regulator_bulk_enable(num, qphy->vregs); + if (ret) + return ret; + + ret = clk_prepare_enable(qphy->iface_clk); + if (ret) { + dev_err(&phy->dev, "failed to enable iface_clk, %d\n", ret); + regulator_bulk_disable(num, qphy->vregs); + return ret; + } + + return 0; +} + +static int qusb2_phy_poweroff(struct phy *phy) +{ + struct qusb2_phy *qphy = phy_get_drvdata(phy); + + clk_disable_unprepare(qphy->iface_clk); + + regulator_bulk_disable(ARRAY_SIZE(qphy->vregs), qphy->vregs); + + return 0; +} + +static int qusb2_phy_init(struct phy *phy) +{ + struct qusb2_phy *qphy = phy_get_drvdata(phy); + unsigned int val; + unsigned int clk_scheme; + int ret; + + dev_vdbg(&phy->dev, "%s(): Initializing QUSB2 phy\n", __func__); + + /* enable ahb interface clock to program phy */ + ret = clk_prepare_enable(qphy->cfg_ahb_clk); + if (ret) { + dev_err(&phy->dev, "failed to enable cfg ahb clock, %d\n", ret); + return ret; + } + + /* Perform phy reset */ + ret = reset_control_assert(qphy->phy_reset); + if (ret) { + dev_err(&phy->dev, "failed to assert phy_reset, %d\n", ret); + goto disable_ahb_clk; + } + + /* 100 us delay to keep PHY in reset mode */ + usleep_range(100, 150); + + ret = reset_control_deassert(qphy->phy_reset); + if (ret) { + dev_err(&phy->dev, "failed to de-assert phy_reset, %d\n", ret); + goto disable_ahb_clk; + } + + /* Disable the PHY */ + qusb2_setbits(qphy->base, QUSB2PHY_PORT_POWERDOWN, + CLAMP_N_EN | FREEZIO_N | POWER_DOWN); + + /* save reset value to override reference clock scheme later */ + val = readl(qphy->base + QUSB2PHY_PLL_TEST); + + qcom_qusb2_phy_configure(qphy->base, qphy->cfg->tbl, + qphy->cfg->tbl_num); + + /* Set efuse value for tuning the PHY */ + qusb2_phy_set_tune2_param(qphy); + + /* Enable the PHY */ + qusb2_clrbits(qphy->base, QUSB2PHY_PORT_POWERDOWN, POWER_DOWN); + + /* Required to get phy pll lock successfully */ + usleep_range(150, 160); + + /* Default is single-ended clock on msm8996 */ + qphy->has_se_clk_scheme = true; + /* + * read TCSR_PHY_CLK_SCHEME register to check if single-ended + * clock scheme is selected. If yes, then disable differential + * ref_clk and use single-ended clock, otherwise use differential + * ref_clk only. + */ + if (qphy->tcsr) { + ret = regmap_read(qphy->tcsr, qphy->cfg->clk_scheme_offset, + &clk_scheme); + if (ret) { + dev_err(&phy->dev, "failed to read clk scheme reg\n"); + goto assert_phy_reset; + } + + /* is it a differential clock scheme ? */ + if (!(clk_scheme & PHY_CLK_SCHEME_SEL)) { + dev_vdbg(&phy->dev, "%s(): select differential clk\n", + __func__); + qphy->has_se_clk_scheme = false; + } else { + dev_vdbg(&phy->dev, "%s(): select single-ended clk\n", + __func__); + } + } + + if (!qphy->has_se_clk_scheme) { + val &= ~CLK_REF_SEL; + ret = clk_prepare_enable(qphy->ref_clk); + if (ret) { + dev_err(&phy->dev, "failed to enable ref clk, %d\n", + ret); + goto assert_phy_reset; + } + } else { + val |= CLK_REF_SEL; + } + + writel(val, qphy->base + QUSB2PHY_PLL_TEST); + + /* ensure above write is through */ + readl(qphy->base + QUSB2PHY_PLL_TEST); + + /* Required to get phy pll lock successfully */ + usleep_range(100, 110); + + val = readb(qphy->base + QUSB2PHY_PLL_STATUS); + if (!(val & PLL_LOCKED)) { + dev_err(&phy->dev, + "QUSB2PHY pll lock failed: status reg = %x\n", val); + ret = -EBUSY; + goto disable_ref_clk; + } + + return 0; + +disable_ref_clk: + if (!qphy->has_se_clk_scheme) + clk_disable_unprepare(qphy->ref_clk); +assert_phy_reset: + reset_control_assert(qphy->phy_reset); +disable_ahb_clk: + clk_disable_unprepare(qphy->cfg_ahb_clk); + return ret; +} + +static int qusb2_phy_exit(struct phy *phy) +{ + struct qusb2_phy *qphy = phy_get_drvdata(phy); + + /* Disable the PHY */ + qusb2_setbits(qphy->base, QUSB2PHY_PORT_POWERDOWN, + CLAMP_N_EN | FREEZIO_N | POWER_DOWN); + + if (!qphy->has_se_clk_scheme) + clk_disable_unprepare(qphy->ref_clk); + + reset_control_assert(qphy->phy_reset); + + clk_disable_unprepare(qphy->cfg_ahb_clk); + + return 0; +} + +static const struct phy_ops qusb2_phy_gen_ops = { + .init = qusb2_phy_init, + .exit = qusb2_phy_exit, + .power_on = qusb2_phy_poweron, + .power_off = qusb2_phy_poweroff, + .owner = THIS_MODULE, +}; + +static const struct of_device_id qusb2_phy_of_match_table[] = { + { + .compatible = "qcom,msm8996-qusb2-phy", + .data = &msm8996_phy_cfg, + }, + { }, +}; +MODULE_DEVICE_TABLE(of, qusb2_phy_of_match_table); + +static int qusb2_phy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct qusb2_phy *qphy; + struct phy_provider *phy_provider; + struct phy *generic_phy; + struct resource *res; + int ret, i; + int num; + + qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL); + if (!qphy) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + qphy->base = devm_ioremap_resource(dev, res); + if (IS_ERR(qphy->base)) + return PTR_ERR(qphy->base); + + qphy->cfg_ahb_clk = devm_clk_get(dev, "cfg_ahb"); + if (IS_ERR(qphy->cfg_ahb_clk)) { + ret = PTR_ERR(qphy->cfg_ahb_clk); + if (ret != -EPROBE_DEFER) + dev_err(dev, "failed to get cfg ahb clk, %d\n", ret); + return ret; + } + + qphy->ref_clk = devm_clk_get(dev, "ref"); + if (IS_ERR(qphy->ref_clk)) { + ret = PTR_ERR(qphy->ref_clk); + if (ret != -EPROBE_DEFER) + dev_err(dev, "failed to get ref clk, %d\n", ret); + return ret; + } + + qphy->iface_clk = devm_clk_get(dev, "iface"); + if (IS_ERR(qphy->iface_clk)) { + ret = PTR_ERR(qphy->iface_clk); + if (ret == -EPROBE_DEFER) + return ret; + qphy->iface_clk = NULL; + dev_dbg(dev, "failed to get iface clk, %d\n", ret); + } + + qphy->phy_reset = devm_reset_control_get_by_index(&pdev->dev, 0); + if (IS_ERR(qphy->phy_reset)) { + dev_err(dev, "failed to get phy core reset\n"); + return PTR_ERR(qphy->phy_reset); + } + + num = ARRAY_SIZE(qphy->vregs); + for (i = 0; i < num; i++) + qphy->vregs[i].supply = qusb2_phy_vreg_names[i]; + + ret = devm_regulator_bulk_get(dev, num, qphy->vregs); + if (ret) { + dev_err(dev, "failed to get regulator supplies\n"); + return ret; + } + + /* Get the specific init parameters of QMP phy */ + qphy->cfg = of_device_get_match_data(dev); + + qphy->tcsr = syscon_regmap_lookup_by_phandle(dev->of_node, + "qcom,tcsr-syscon"); + if (IS_ERR(qphy->tcsr)) { + dev_dbg(dev, "failed to lookup TCSR regmap\n"); + qphy->tcsr = NULL; + } + + qphy->cell = devm_nvmem_cell_get(dev, NULL); + if (IS_ERR(qphy->cell)) { + if (PTR_ERR(qphy->cell) == -EPROBE_DEFER) + return -EPROBE_DEFER; + qphy->cell = NULL; + dev_dbg(dev, "failed to lookup tune2 hstx trim value\n"); + } + + generic_phy = devm_phy_create(dev, NULL, &qusb2_phy_gen_ops); + if (IS_ERR(generic_phy)) { + ret = PTR_ERR(generic_phy); + dev_err(dev, "failed to create phy, %d\n", ret); + return ret; + } + qphy->phy = generic_phy; + + dev_set_drvdata(dev, qphy); + phy_set_drvdata(generic_phy, qphy); + + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); + if (!IS_ERR(phy_provider)) + dev_info(dev, "Registered Qcom-QUSB2 phy\n"); + + return PTR_ERR_OR_ZERO(phy_provider); +} + +static struct platform_driver qusb2_phy_driver = { + .probe = qusb2_phy_probe, + .driver = { + .name = "qcom-qusb2-phy", + .of_match_table = qusb2_phy_of_match_table, + }, +}; + +module_platform_driver(qusb2_phy_driver); + +MODULE_AUTHOR("Vivek Gautam <vivek.gautam@codeaurora.org>"); +MODULE_DESCRIPTION("Qualcomm QUSB2 PHY driver"); +MODULE_LICENSE("GPL v2"); |