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203 lines
5.0 KiB
203 lines
5.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* IMG Pistachio USB PHY driver |
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* |
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* Copyright (C) 2015 Google, Inc. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/delay.h> |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/mfd/syscon.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/phy/phy.h> |
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#include <linux/platform_device.h> |
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#include <linux/regmap.h> |
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#include <dt-bindings/phy/phy-pistachio-usb.h> |
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#define USB_PHY_CONTROL1 0x04 |
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#define USB_PHY_CONTROL1_FSEL_SHIFT 2 |
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#define USB_PHY_CONTROL1_FSEL_MASK 0x7 |
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#define USB_PHY_STRAP_CONTROL 0x10 |
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#define USB_PHY_STRAP_CONTROL_REFCLK_SHIFT 4 |
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#define USB_PHY_STRAP_CONTROL_REFCLK_MASK 0x3 |
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#define USB_PHY_STATUS 0x14 |
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#define USB_PHY_STATUS_RX_PHY_CLK BIT(9) |
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#define USB_PHY_STATUS_RX_UTMI_CLK BIT(8) |
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#define USB_PHY_STATUS_VBUS_FAULT BIT(7) |
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struct pistachio_usb_phy { |
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struct device *dev; |
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struct regmap *cr_top; |
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struct clk *phy_clk; |
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unsigned int refclk; |
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}; |
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static const unsigned long fsel_rate_map[] = { |
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9600000, |
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10000000, |
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12000000, |
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19200000, |
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20000000, |
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24000000, |
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0, |
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50000000, |
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}; |
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static int pistachio_usb_phy_power_on(struct phy *phy) |
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{ |
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struct pistachio_usb_phy *p_phy = phy_get_drvdata(phy); |
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unsigned long timeout, rate; |
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unsigned int i; |
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int ret; |
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ret = clk_prepare_enable(p_phy->phy_clk); |
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if (ret < 0) { |
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dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret); |
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return ret; |
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} |
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regmap_update_bits(p_phy->cr_top, USB_PHY_STRAP_CONTROL, |
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USB_PHY_STRAP_CONTROL_REFCLK_MASK << |
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USB_PHY_STRAP_CONTROL_REFCLK_SHIFT, |
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p_phy->refclk << USB_PHY_STRAP_CONTROL_REFCLK_SHIFT); |
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rate = clk_get_rate(p_phy->phy_clk); |
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if (p_phy->refclk == REFCLK_XO_CRYSTAL && rate != 12000000) { |
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dev_err(p_phy->dev, "Unsupported rate for XO crystal: %ld\n", |
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rate); |
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ret = -EINVAL; |
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goto disable_clk; |
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} |
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for (i = 0; i < ARRAY_SIZE(fsel_rate_map); i++) { |
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if (rate == fsel_rate_map[i]) |
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break; |
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} |
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if (i == ARRAY_SIZE(fsel_rate_map)) { |
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dev_err(p_phy->dev, "Unsupported clock rate: %lu\n", rate); |
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ret = -EINVAL; |
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goto disable_clk; |
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} |
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regmap_update_bits(p_phy->cr_top, USB_PHY_CONTROL1, |
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USB_PHY_CONTROL1_FSEL_MASK << |
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USB_PHY_CONTROL1_FSEL_SHIFT, |
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i << USB_PHY_CONTROL1_FSEL_SHIFT); |
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timeout = jiffies + msecs_to_jiffies(200); |
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while (time_before(jiffies, timeout)) { |
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unsigned int val; |
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regmap_read(p_phy->cr_top, USB_PHY_STATUS, &val); |
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if (val & USB_PHY_STATUS_VBUS_FAULT) { |
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dev_err(p_phy->dev, "VBUS fault detected\n"); |
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ret = -EIO; |
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goto disable_clk; |
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} |
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if ((val & USB_PHY_STATUS_RX_PHY_CLK) && |
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(val & USB_PHY_STATUS_RX_UTMI_CLK)) |
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return 0; |
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usleep_range(1000, 1500); |
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} |
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dev_err(p_phy->dev, "Timed out waiting for PHY to power on\n"); |
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ret = -ETIMEDOUT; |
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disable_clk: |
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clk_disable_unprepare(p_phy->phy_clk); |
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return ret; |
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} |
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static int pistachio_usb_phy_power_off(struct phy *phy) |
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{ |
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struct pistachio_usb_phy *p_phy = phy_get_drvdata(phy); |
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clk_disable_unprepare(p_phy->phy_clk); |
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return 0; |
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} |
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static const struct phy_ops pistachio_usb_phy_ops = { |
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.power_on = pistachio_usb_phy_power_on, |
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.power_off = pistachio_usb_phy_power_off, |
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.owner = THIS_MODULE, |
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}; |
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static int pistachio_usb_phy_probe(struct platform_device *pdev) |
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{ |
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struct pistachio_usb_phy *p_phy; |
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struct phy_provider *provider; |
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struct phy *phy; |
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int ret; |
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p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL); |
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if (!p_phy) |
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return -ENOMEM; |
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p_phy->dev = &pdev->dev; |
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platform_set_drvdata(pdev, p_phy); |
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p_phy->cr_top = syscon_regmap_lookup_by_phandle(p_phy->dev->of_node, |
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"img,cr-top"); |
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if (IS_ERR(p_phy->cr_top)) { |
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dev_err(p_phy->dev, "Failed to get CR_TOP registers: %ld\n", |
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PTR_ERR(p_phy->cr_top)); |
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return PTR_ERR(p_phy->cr_top); |
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} |
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p_phy->phy_clk = devm_clk_get(p_phy->dev, "usb_phy"); |
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if (IS_ERR(p_phy->phy_clk)) { |
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dev_err(p_phy->dev, "Failed to get usb_phy clock: %ld\n", |
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PTR_ERR(p_phy->phy_clk)); |
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return PTR_ERR(p_phy->phy_clk); |
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} |
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ret = of_property_read_u32(p_phy->dev->of_node, "img,refclk", |
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&p_phy->refclk); |
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if (ret < 0) { |
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dev_err(p_phy->dev, "No reference clock selector specified\n"); |
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return ret; |
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} |
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phy = devm_phy_create(p_phy->dev, NULL, &pistachio_usb_phy_ops); |
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if (IS_ERR(phy)) { |
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dev_err(p_phy->dev, "Failed to create PHY: %ld\n", |
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PTR_ERR(phy)); |
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return PTR_ERR(phy); |
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} |
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phy_set_drvdata(phy, p_phy); |
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provider = devm_of_phy_provider_register(p_phy->dev, |
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of_phy_simple_xlate); |
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if (IS_ERR(provider)) { |
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dev_err(p_phy->dev, "Failed to register PHY provider: %ld\n", |
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PTR_ERR(provider)); |
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return PTR_ERR(provider); |
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} |
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return 0; |
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} |
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static const struct of_device_id pistachio_usb_phy_of_match[] = { |
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{ .compatible = "img,pistachio-usb-phy", }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, pistachio_usb_phy_of_match); |
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static struct platform_driver pistachio_usb_phy_driver = { |
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.probe = pistachio_usb_phy_probe, |
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.driver = { |
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.name = "pistachio-usb-phy", |
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.of_match_table = pistachio_usb_phy_of_match, |
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}, |
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}; |
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module_platform_driver(pistachio_usb_phy_driver); |
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MODULE_AUTHOR("Andrew Bresticker <[email protected]>"); |
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MODULE_DESCRIPTION("IMG Pistachio USB2.0 PHY driver"); |
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MODULE_LICENSE("GPL v2");
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