1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * DaVinci DM816 AHCI SATA platform driver
4 *
5 * Copyright (C) 2017 BayLibre SAS
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
ahci_dm816_get_mpy_bits(unsigned long refclk_rate)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
ahci_dm816_phy_init(struct ahci_host_priv * hpriv,struct device * dev)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
ahci_dm816_softreset(struct ata_link * link,unsigned int * class,unsigned long deadline)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
ahci_dm816_probe(struct platform_device * pdev)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
147 hpriv = ahci_platform_get_resources(pdev, 0);
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");
197