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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Mediatek MT7621 PCI PHY Driver
  4 * Author: Sergio Paracuellos <sergio.paracuellos@gmail.com>
  5 */
  6
  7#include <dt-bindings/phy/phy.h>
  8#include <linux/clk.h>
  9#include <linux/bitfield.h>
 10#include <linux/bitops.h>
 11#include <linux/module.h>
 12#include <linux/of_address.h>
 13#include <linux/of_device.h>
 14#include <linux/phy/phy.h>
 15#include <linux/platform_device.h>
 16#include <linux/regmap.h>
 17#include <linux/sys_soc.h>
 18
 19#define RG_PE1_PIPE_REG				0x02c
 20#define RG_PE1_PIPE_RST				BIT(12)
 21#define RG_PE1_PIPE_CMD_FRC			BIT(4)
 22
 23#define RG_P0_TO_P1_WIDTH			0x100
 24#define RG_PE1_H_LCDDS_REG			0x49c
 25#define RG_PE1_H_LCDDS_PCW			GENMASK(30, 0)
 26
 27#define RG_PE1_FRC_H_XTAL_REG			0x400
 28#define RG_PE1_FRC_H_XTAL_TYPE			BIT(8)
 29#define RG_PE1_H_XTAL_TYPE			GENMASK(10, 9)
 30
 31#define RG_PE1_FRC_PHY_REG			0x000
 32#define RG_PE1_FRC_PHY_EN			BIT(4)
 33#define RG_PE1_PHY_EN				BIT(5)
 34
 35#define RG_PE1_H_PLL_REG			0x490
 36#define RG_PE1_H_PLL_BC				GENMASK(23, 22)
 37#define RG_PE1_H_PLL_BP				GENMASK(21, 18)
 38#define RG_PE1_H_PLL_IR				GENMASK(15, 12)
 39#define RG_PE1_H_PLL_IC				GENMASK(11, 8)
 40#define RG_PE1_H_PLL_PREDIV			GENMASK(7, 6)
 41#define RG_PE1_PLL_DIVEN			GENMASK(3, 1)
 42
 43#define RG_PE1_H_PLL_FBKSEL_REG			0x4bc
 44#define RG_PE1_H_PLL_FBKSEL			GENMASK(5, 4)
 45
 46#define	RG_PE1_H_LCDDS_SSC_PRD_REG		0x4a4
 47#define RG_PE1_H_LCDDS_SSC_PRD			GENMASK(15, 0)
 48
 49#define RG_PE1_H_LCDDS_SSC_DELTA_REG		0x4a8
 50#define RG_PE1_H_LCDDS_SSC_DELTA		GENMASK(11, 0)
 51#define RG_PE1_H_LCDDS_SSC_DELTA1		GENMASK(27, 16)
 52
 53#define RG_PE1_LCDDS_CLK_PH_INV_REG		0x4a0
 54#define RG_PE1_LCDDS_CLK_PH_INV			BIT(5)
 55
 56#define RG_PE1_H_PLL_BR_REG			0x4ac
 57#define RG_PE1_H_PLL_BR				GENMASK(18, 16)
 58
 59#define	RG_PE1_MSTCKDIV_REG			0x414
 60#define RG_PE1_MSTCKDIV				GENMASK(7, 6)
 61
 62#define RG_PE1_FRC_MSTCKDIV			BIT(5)
 63
 64#define MAX_PHYS	2
 65
 66/**
 67 * struct mt7621_pci_phy - Mt7621 Pcie PHY core
 68 * @dev: pointer to device
 69 * @regmap: kernel regmap pointer
 70 * @phy: pointer to the kernel PHY device
 71 * @sys_clk: pointer to the system XTAL clock
 72 * @port_base: base register
 73 * @has_dual_port: if the phy has dual ports.
 74 * @bypass_pipe_rst: mark if 'mt7621_bypass_pipe_rst'
 75 * needs to be executed. Depends on chip revision.
 76 */
 77struct mt7621_pci_phy {
 78	struct device *dev;
 79	struct regmap *regmap;
 80	struct phy *phy;
 81	struct clk *sys_clk;
 82	void __iomem *port_base;
 83	bool has_dual_port;
 84	bool bypass_pipe_rst;
 85};
 86
 87static inline void mt7621_phy_rmw(struct mt7621_pci_phy *phy,
 88				  u32 reg, u32 clr, u32 set)
 89{
 90	u32 val;
 91
 92	/*
 93	 * We cannot use 'regmap_write_bits' here because internally
 94	 * 'set' is masked before is set to the value that will be
 95	 * written to the register. That way results in no reliable
 96	 * pci setup. Avoid to mask 'set' before set value to 'val'
 97	 * completely avoid the problem.
 98	 */
 99	regmap_read(phy->regmap, reg, &val);
100	val &= ~clr;
101	val |= set;
102	regmap_write(phy->regmap, reg, val);
103}
104
105static void mt7621_bypass_pipe_rst(struct mt7621_pci_phy *phy)
106{
107	mt7621_phy_rmw(phy, RG_PE1_PIPE_REG, 0, RG_PE1_PIPE_RST);
108	mt7621_phy_rmw(phy, RG_PE1_PIPE_REG, 0, RG_PE1_PIPE_CMD_FRC);
109
110	if (phy->has_dual_port) {
111		mt7621_phy_rmw(phy, RG_PE1_PIPE_REG + RG_P0_TO_P1_WIDTH,
112			       0, RG_PE1_PIPE_RST);
113		mt7621_phy_rmw(phy, RG_PE1_PIPE_REG + RG_P0_TO_P1_WIDTH,
114			       0, RG_PE1_PIPE_CMD_FRC);
115	}
116}
117
118static int mt7621_set_phy_for_ssc(struct mt7621_pci_phy *phy)
119{
120	struct device *dev = phy->dev;
121	unsigned long clk_rate;
122
123	clk_rate = clk_get_rate(phy->sys_clk);
124	if (!clk_rate)
125		return -EINVAL;
126
127	/* Set PCIe Port PHY to disable SSC */
128	/* Debug Xtal Type */
129	mt7621_phy_rmw(phy, RG_PE1_FRC_H_XTAL_REG,
130		       RG_PE1_FRC_H_XTAL_TYPE | RG_PE1_H_XTAL_TYPE,
131		       RG_PE1_FRC_H_XTAL_TYPE |
132		       FIELD_PREP(RG_PE1_H_XTAL_TYPE, 0x00));
133
134	/* disable port */
135	mt7621_phy_rmw(phy, RG_PE1_FRC_PHY_REG, RG_PE1_PHY_EN,
136		       RG_PE1_FRC_PHY_EN);
137
138	if (phy->has_dual_port) {
139		mt7621_phy_rmw(phy, RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH,
140			       RG_PE1_PHY_EN, RG_PE1_FRC_PHY_EN);
141	}
142
143	if (clk_rate == 40000000) { /* 40MHz Xtal */
144		/* Set Pre-divider ratio (for host mode) */
145		mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG, RG_PE1_H_PLL_PREDIV,
146			       FIELD_PREP(RG_PE1_H_PLL_PREDIV, 0x01));
147
148		dev_dbg(dev, "Xtal is 40MHz\n");
149	} else if (clk_rate == 25000000) { /* 25MHz Xal */
150		mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG, RG_PE1_H_PLL_PREDIV,
151			       FIELD_PREP(RG_PE1_H_PLL_PREDIV, 0x00));
152
153		/* Select feedback clock */
154		mt7621_phy_rmw(phy, RG_PE1_H_PLL_FBKSEL_REG,
155			       RG_PE1_H_PLL_FBKSEL,
156			       FIELD_PREP(RG_PE1_H_PLL_FBKSEL, 0x01));
157
158		/* DDS NCPO PCW (for host mode) */
159		mt7621_phy_rmw(phy, RG_PE1_H_LCDDS_SSC_PRD_REG,
160			       RG_PE1_H_LCDDS_SSC_PRD,
161			       FIELD_PREP(RG_PE1_H_LCDDS_SSC_PRD, 0x00));
162
163		/* DDS SSC dither period control */
164		mt7621_phy_rmw(phy, RG_PE1_H_LCDDS_SSC_PRD_REG,
165			       RG_PE1_H_LCDDS_SSC_PRD,
166			       FIELD_PREP(RG_PE1_H_LCDDS_SSC_PRD, 0x18d));
167
168		/* DDS SSC dither amplitude control */
169		mt7621_phy_rmw(phy, RG_PE1_H_LCDDS_SSC_DELTA_REG,
170			       RG_PE1_H_LCDDS_SSC_DELTA |
171			       RG_PE1_H_LCDDS_SSC_DELTA1,
172			       FIELD_PREP(RG_PE1_H_LCDDS_SSC_DELTA, 0x4a) |
173			       FIELD_PREP(RG_PE1_H_LCDDS_SSC_DELTA1, 0x4a));
174
175		dev_dbg(dev, "Xtal is 25MHz\n");
176	} else { /* 20MHz Xtal */
177		mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG, RG_PE1_H_PLL_PREDIV,
178			       FIELD_PREP(RG_PE1_H_PLL_PREDIV, 0x00));
179
180		dev_dbg(dev, "Xtal is 20MHz\n");
181	}
182
183	/* DDS clock inversion */
184	mt7621_phy_rmw(phy, RG_PE1_LCDDS_CLK_PH_INV_REG,
185		       RG_PE1_LCDDS_CLK_PH_INV, RG_PE1_LCDDS_CLK_PH_INV);
186
187	/* Set PLL bits */
188	mt7621_phy_rmw(phy, RG_PE1_H_PLL_REG,
189		       RG_PE1_H_PLL_BC | RG_PE1_H_PLL_BP | RG_PE1_H_PLL_IR |
190		       RG_PE1_H_PLL_IC | RG_PE1_PLL_DIVEN,
191		       FIELD_PREP(RG_PE1_H_PLL_BC, 0x02) |
192		       FIELD_PREP(RG_PE1_H_PLL_BP, 0x06) |
193		       FIELD_PREP(RG_PE1_H_PLL_IR, 0x02) |
194		       FIELD_PREP(RG_PE1_H_PLL_IC, 0x01) |
195		       FIELD_PREP(RG_PE1_PLL_DIVEN, 0x02));
196
197	mt7621_phy_rmw(phy, RG_PE1_H_PLL_BR_REG, RG_PE1_H_PLL_BR,
198		       FIELD_PREP(RG_PE1_H_PLL_BR, 0x00));
199
200	if (clk_rate == 40000000) { /* 40MHz Xtal */
201		/* set force mode enable of da_pe1_mstckdiv */
202		mt7621_phy_rmw(phy, RG_PE1_MSTCKDIV_REG,
203			       RG_PE1_MSTCKDIV | RG_PE1_FRC_MSTCKDIV,
204			       FIELD_PREP(RG_PE1_MSTCKDIV, 0x01) |
205			       RG_PE1_FRC_MSTCKDIV);
206	}
207
208	return 0;
209}
210
211static int mt7621_pci_phy_init(struct phy *phy)
212{
213	struct mt7621_pci_phy *mphy = phy_get_drvdata(phy);
214
215	if (mphy->bypass_pipe_rst)
216		mt7621_bypass_pipe_rst(mphy);
217
218	return mt7621_set_phy_for_ssc(mphy);
219}
220
221static int mt7621_pci_phy_power_on(struct phy *phy)
222{
223	struct mt7621_pci_phy *mphy = phy_get_drvdata(phy);
224
225	/* Enable PHY and disable force mode */
226	mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG,
227		       RG_PE1_FRC_PHY_EN, RG_PE1_PHY_EN);
228
229	if (mphy->has_dual_port) {
230		mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH,
231			       RG_PE1_FRC_PHY_EN, RG_PE1_PHY_EN);
232	}
233
234	return 0;
235}
236
237static int mt7621_pci_phy_power_off(struct phy *phy)
238{
239	struct mt7621_pci_phy *mphy = phy_get_drvdata(phy);
240
241	/* Disable PHY */
242	mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG,
243		       RG_PE1_PHY_EN, RG_PE1_FRC_PHY_EN);
244
245	if (mphy->has_dual_port) {
246		mt7621_phy_rmw(mphy, RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH,
247			       RG_PE1_PHY_EN, RG_PE1_FRC_PHY_EN);
248	}
249
250	return 0;
251}
252
253static int mt7621_pci_phy_exit(struct phy *phy)
254{
255	return 0;
256}
257
258static const struct phy_ops mt7621_pci_phy_ops = {
259	.init		= mt7621_pci_phy_init,
260	.exit		= mt7621_pci_phy_exit,
261	.power_on	= mt7621_pci_phy_power_on,
262	.power_off	= mt7621_pci_phy_power_off,
263	.owner		= THIS_MODULE,
264};
265
266static struct phy *mt7621_pcie_phy_of_xlate(struct device *dev,
267					    struct of_phandle_args *args)
268{
269	struct mt7621_pci_phy *mt7621_phy = dev_get_drvdata(dev);
270
271	if (WARN_ON(args->args[0] >= MAX_PHYS))
272		return ERR_PTR(-ENODEV);
273
274	mt7621_phy->has_dual_port = args->args[0];
275
276	dev_dbg(dev, "PHY for 0x%px (dual port = %d)\n",
277		mt7621_phy->port_base, mt7621_phy->has_dual_port);
278
279	return mt7621_phy->phy;
280}
281
282static const struct soc_device_attribute mt7621_pci_quirks_match[] = {
283	{ .soc_id = "mt7621", .revision = "E2" },
284	{ /* sentinel */ }
285};
286
287static const struct regmap_config mt7621_pci_phy_regmap_config = {
288	.reg_bits = 32,
289	.val_bits = 32,
290	.reg_stride = 4,
291	.max_register = 0x700,
292};
293
294static int mt7621_pci_phy_probe(struct platform_device *pdev)
295{
296	struct device *dev = &pdev->dev;
297	const struct soc_device_attribute *attr;
298	struct phy_provider *provider;
299	struct mt7621_pci_phy *phy;
300
301	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
302	if (!phy)
303		return -ENOMEM;
304
305	attr = soc_device_match(mt7621_pci_quirks_match);
306	if (attr)
307		phy->bypass_pipe_rst = true;
308
309	phy->dev = dev;
310	platform_set_drvdata(pdev, phy);
311
312	phy->port_base = devm_platform_ioremap_resource(pdev, 0);
313	if (IS_ERR(phy->port_base)) {
314		dev_err(dev, "failed to remap phy regs\n");
315		return PTR_ERR(phy->port_base);
316	}
317
318	phy->regmap = devm_regmap_init_mmio(phy->dev, phy->port_base,
319					    &mt7621_pci_phy_regmap_config);
320	if (IS_ERR(phy->regmap))
321		return PTR_ERR(phy->regmap);
322
323	phy->phy = devm_phy_create(dev, dev->of_node, &mt7621_pci_phy_ops);
324	if (IS_ERR(phy->phy)) {
325		dev_err(dev, "failed to create phy\n");
326		return PTR_ERR(phy->phy);
327	}
328
329	phy->sys_clk = devm_clk_get(dev, NULL);
330	if (IS_ERR(phy->sys_clk)) {
331		dev_err(dev, "failed to get phy clock\n");
332		return PTR_ERR(phy->sys_clk);
333	}
334
335	phy_set_drvdata(phy->phy, phy);
336
337	provider = devm_of_phy_provider_register(dev, mt7621_pcie_phy_of_xlate);
338
339	return PTR_ERR_OR_ZERO(provider);
340}
341
342static const struct of_device_id mt7621_pci_phy_ids[] = {
343	{ .compatible = "mediatek,mt7621-pci-phy" },
344	{},
345};
346MODULE_DEVICE_TABLE(of, mt7621_pci_phy_ids);
347
348static struct platform_driver mt7621_pci_phy_driver = {
349	.probe = mt7621_pci_phy_probe,
350	.driver = {
351		.name = "mt7621-pci-phy",
352		.of_match_table = mt7621_pci_phy_ids,
353	},
354};
355
356builtin_platform_driver(mt7621_pci_phy_driver);
357
358MODULE_AUTHOR("Sergio Paracuellos <sergio.paracuellos@gmail.com>");
359MODULE_DESCRIPTION("MediaTek MT7621 PCIe PHY driver");
360MODULE_LICENSE("GPL v2");