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 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->n_clks < 2) { 73 dev_err(dev, "reference clock not supplied\n"); 74 return -EINVAL; 75 } 76 77 refclk_rate = clk_get_rate(hpriv->clks[1].clk); 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; 146 147 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 { /* sentinel */ } 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