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8d7c56d0 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
df46e6a4 BG |
2 | /* |
3 | * DaVinci DM816 AHCI SATA platform driver | |
4 | * | |
5 | * Copyright (C) 2017 BayLibre SAS | |
df46e6a4 BG |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/device.h> | |
11 | #include <linux/pm.h> | |
12 | #include <linux/platform_device.h> | |
13 | #include <linux/libata.h> | |
14 | #include <linux/ahci_platform.h> | |
15 | ||
16 | #include "ahci.h" | |
17 | ||
18 | #define AHCI_DM816_DRV_NAME "ahci-dm816" | |
19 | ||
20 | #define AHCI_DM816_PHY_ENPLL(x) ((x) << 0) | |
21 | #define AHCI_DM816_PHY_MPY(x) ((x) << 1) | |
22 | #define AHCI_DM816_PHY_LOS(x) ((x) << 12) | |
23 | #define AHCI_DM816_PHY_RXCDR(x) ((x) << 13) | |
24 | #define AHCI_DM816_PHY_RXEQ(x) ((x) << 16) | |
25 | #define AHCI_DM816_PHY_TXSWING(x) ((x) << 23) | |
26 | ||
27 | #define AHCI_DM816_P0PHYCR_REG 0x178 | |
28 | #define AHCI_DM816_P1PHYCR_REG 0x1f8 | |
29 | ||
30 | #define AHCI_DM816_PLL_OUT 1500000000LU | |
31 | ||
32 | static const unsigned long pll_mpy_table[] = { | |
33 | 400, 500, 600, 800, 825, 1000, 1200, | |
34 | 1250, 1500, 1600, 1650, 2000, 2200, 2500 | |
35 | }; | |
36 | ||
37 | static int ahci_dm816_get_mpy_bits(unsigned long refclk_rate) | |
38 | { | |
39 | unsigned long pll_multiplier; | |
40 | int i; | |
41 | ||
42 | /* | |
43 | * We need to determine the value of the multiplier (MPY) bits. | |
44 | * In order to include the 8.25 multiplier we need to first divide | |
45 | * the refclk rate by 100. | |
46 | */ | |
47 | pll_multiplier = AHCI_DM816_PLL_OUT / (refclk_rate / 100); | |
48 | ||
49 | for (i = 0; i < ARRAY_SIZE(pll_mpy_table); i++) { | |
50 | if (pll_mpy_table[i] == pll_multiplier) | |
51 | return i; | |
52 | } | |
53 | ||
54 | /* | |
55 | * We should have divided evenly - if not, return an invalid | |
56 | * value. | |
57 | */ | |
58 | return -1; | |
59 | } | |
60 | ||
61 | static int ahci_dm816_phy_init(struct ahci_host_priv *hpriv, struct device *dev) | |
62 | { | |
63 | unsigned long refclk_rate; | |
64 | int mpy; | |
65 | u32 val; | |
66 | ||
67 | /* | |
68 | * We should have been supplied two clocks: the functional and | |
69 | * keep-alive clock and the external reference clock. We need the | |
70 | * rate of the latter to calculate the correct value of MPY bits. | |
71 | */ | |
72 | if (!hpriv->clks[1]) { | |
73 | dev_err(dev, "reference clock not supplied\n"); | |
74 | return -EINVAL; | |
75 | } | |
76 | ||
77 | refclk_rate = clk_get_rate(hpriv->clks[1]); | |
78 | if ((refclk_rate % 100) != 0) { | |
79 | dev_err(dev, "reference clock rate must be divisible by 100\n"); | |
80 | return -EINVAL; | |
81 | } | |
82 | ||
83 | mpy = ahci_dm816_get_mpy_bits(refclk_rate); | |
84 | if (mpy < 0) { | |
85 | dev_err(dev, "can't calculate the MPY bits value\n"); | |
86 | return -EINVAL; | |
87 | } | |
88 | ||
89 | /* Enable the PHY and configure the first HBA port. */ | |
90 | val = AHCI_DM816_PHY_MPY(mpy) | AHCI_DM816_PHY_LOS(1) | | |
91 | AHCI_DM816_PHY_RXCDR(4) | AHCI_DM816_PHY_RXEQ(1) | | |
92 | AHCI_DM816_PHY_TXSWING(3) | AHCI_DM816_PHY_ENPLL(1); | |
93 | writel(val, hpriv->mmio + AHCI_DM816_P0PHYCR_REG); | |
94 | ||
95 | /* Configure the second HBA port. */ | |
96 | val = AHCI_DM816_PHY_LOS(1) | AHCI_DM816_PHY_RXCDR(4) | | |
97 | AHCI_DM816_PHY_RXEQ(1) | AHCI_DM816_PHY_TXSWING(3); | |
98 | writel(val, hpriv->mmio + AHCI_DM816_P1PHYCR_REG); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | static int ahci_dm816_softreset(struct ata_link *link, | |
104 | unsigned int *class, unsigned long deadline) | |
105 | { | |
106 | int pmp, ret; | |
107 | ||
108 | pmp = sata_srst_pmp(link); | |
109 | ||
110 | /* | |
111 | * There's an issue with the SATA controller on DM816 SoC: if we | |
112 | * enable Port Multiplier support, but the drive is connected directly | |
113 | * to the board, it can't be detected. As a workaround: if PMP is | |
114 | * enabled, we first call ahci_do_softreset() and pass it the result of | |
115 | * sata_srst_pmp(). If this call fails, we retry with pmp = 0. | |
116 | */ | |
117 | ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready); | |
118 | if (pmp && ret == -EBUSY) | |
119 | return ahci_do_softreset(link, class, 0, | |
120 | deadline, ahci_check_ready); | |
121 | ||
122 | return ret; | |
123 | } | |
124 | ||
125 | static struct ata_port_operations ahci_dm816_port_ops = { | |
126 | .inherits = &ahci_platform_ops, | |
127 | .softreset = ahci_dm816_softreset, | |
128 | }; | |
129 | ||
130 | static const struct ata_port_info ahci_dm816_port_info = { | |
131 | .flags = AHCI_FLAG_COMMON, | |
132 | .pio_mask = ATA_PIO4, | |
133 | .udma_mask = ATA_UDMA6, | |
134 | .port_ops = &ahci_dm816_port_ops, | |
135 | }; | |
136 | ||
137 | static struct scsi_host_template ahci_dm816_platform_sht = { | |
138 | AHCI_SHT(AHCI_DM816_DRV_NAME), | |
139 | }; | |
140 | ||
141 | static int ahci_dm816_probe(struct platform_device *pdev) | |
142 | { | |
143 | struct device *dev = &pdev->dev; | |
144 | struct ahci_host_priv *hpriv; | |
145 | int rc; | |
146 | ||
16af2d65 | 147 | hpriv = ahci_platform_get_resources(pdev, 0); |
df46e6a4 BG |
148 | if (IS_ERR(hpriv)) |
149 | return PTR_ERR(hpriv); | |
150 | ||
151 | rc = ahci_platform_enable_resources(hpriv); | |
152 | if (rc) | |
153 | return rc; | |
154 | ||
155 | rc = ahci_dm816_phy_init(hpriv, dev); | |
156 | if (rc) | |
157 | goto disable_resources; | |
158 | ||
159 | rc = ahci_platform_init_host(pdev, hpriv, | |
160 | &ahci_dm816_port_info, | |
161 | &ahci_dm816_platform_sht); | |
162 | if (rc) | |
163 | goto disable_resources; | |
164 | ||
165 | return 0; | |
166 | ||
167 | disable_resources: | |
168 | ahci_platform_disable_resources(hpriv); | |
169 | ||
170 | return rc; | |
171 | } | |
172 | ||
173 | static SIMPLE_DEV_PM_OPS(ahci_dm816_pm_ops, | |
174 | ahci_platform_suspend, | |
175 | ahci_platform_resume); | |
176 | ||
177 | static const struct of_device_id ahci_dm816_of_match[] = { | |
178 | { .compatible = "ti,dm816-ahci", }, | |
179 | { }, | |
180 | }; | |
181 | MODULE_DEVICE_TABLE(of, ahci_dm816_of_match); | |
182 | ||
183 | static struct platform_driver ahci_dm816_driver = { | |
184 | .probe = ahci_dm816_probe, | |
185 | .remove = ata_platform_remove_one, | |
186 | .driver = { | |
187 | .name = AHCI_DM816_DRV_NAME, | |
188 | .of_match_table = ahci_dm816_of_match, | |
189 | .pm = &ahci_dm816_pm_ops, | |
190 | }, | |
191 | }; | |
192 | module_platform_driver(ahci_dm816_driver); | |
193 | ||
194 | MODULE_DESCRIPTION("DaVinci DM816 AHCI SATA platform driver"); | |
195 | MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>"); | |
196 | MODULE_LICENSE("GPL"); |