drivers/i3c/master/mipi-i3c-hci/dat_v1.c

   1 // SPDX-License-Identifier: BSD-3-Clause
   2 /*
   3  * Copyright (c) 2020, MIPI Alliance, Inc.
   4  *
   5  * Author: Nicolas Pitre <npitre@baylibre.com>
   6  */
   7
   8 #include <linux/bitfield.h>
   9 #include <linux/bitmap.h>
  10 #include <linux/device.h>
  11 #include <linux/errno.h>
  12 #include <linux/i3c/master.h>
  13 #include <linux/io.h>
  14
  15 #include "hci.h"
  16 #include "dat.h"
  17
  18
  19 /*
  20  * Device Address Table Structure
  21  */
  22
  23 #define DAT_1_AUTOCMD_HDR_CODE          W1_MASK(58, 51)
  24 #define DAT_1_AUTOCMD_MODE              W1_MASK(50, 48)
  25 #define DAT_1_AUTOCMD_VALUE             W1_MASK(47, 40)
  26 #define DAT_1_AUTOCMD_MASK              W1_MASK(39, 32)
  27 /*      DAT_0_I2C_DEVICE                W0_BIT_(31) */
  28 #define DAT_0_DEV_NACK_RETRY_CNT        W0_MASK(30, 29)
  29 #define DAT_0_RING_ID                   W0_MASK(28, 26)
  30 #define DAT_0_DYNADDR_PARITY            W0_BIT_(23)
  31 #define DAT_0_DYNAMIC_ADDRESS           W0_MASK(22, 16)
  32 #define DAT_0_TS                        W0_BIT_(15)
  33 #define DAT_0_MR_REJECT                 W0_BIT_(14)
  34 /*      DAT_0_SIR_REJECT                W0_BIT_(13) */
  35 /*      DAT_0_IBI_PAYLOAD               W0_BIT_(12) */
  36 #define DAT_0_STATIC_ADDRESS            W0_MASK(6, 0)
  37
  38 #define dat_w0_read(i)          readl(hci->DAT_regs + (i) * 8)
  39 #define dat_w1_read(i)          readl(hci->DAT_regs + (i) * 8 + 4)
  40 #define dat_w0_write(i, v)      writel(v, hci->DAT_regs + (i) * 8)
  41 #define dat_w1_write(i, v)      writel(v, hci->DAT_regs + (i) * 8 + 4)
  42
  43 static inline bool dynaddr_parity(unsigned int addr)
  44 {
  45         addr |= 1 << 7;
  46         addr += addr >> 4;
  47         addr += addr >> 2;
  48         addr += addr >> 1;
  49         return (addr & 1);
  50 }
  51
  52 static int hci_dat_v1_init(struct i3c_hci *hci)
  53 {
  54         unsigned int dat_idx;
  55
  56         if (!hci->DAT_regs) {
  57                 dev_err(&hci->master.dev,
  58                         "only DAT in register space is supported at the moment\n");
  59                 return -EOPNOTSUPP;
  60         }
  61         if (hci->DAT_entry_size != 8) {
  62                 dev_err(&hci->master.dev,
  63                         "only 8-bytes DAT entries are supported at the moment\n");
  64                 return -EOPNOTSUPP;
  65         }
  66
  67         if (!hci->DAT_data) {
  68                 /* use a bitmap for faster free slot search */
  69                 hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL);
  70                 if (!hci->DAT_data)
  71                         return -ENOMEM;
  72
  73                 /* clear them */
  74                 for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) {
  75                         dat_w0_write(dat_idx, 0);
  76                         dat_w1_write(dat_idx, 0);
  77                 }
  78         }
  79
  80         return 0;
  81 }
  82
  83 static void hci_dat_v1_cleanup(struct i3c_hci *hci)
  84 {
  85         bitmap_free(hci->DAT_data);
  86         hci->DAT_data = NULL;
  87 }
  88
  89 static int hci_dat_v1_alloc_entry(struct i3c_hci *hci)
  90 {
  91         unsigned int dat_idx;
  92         int ret;
  93
  94         if (!hci->DAT_data) {
  95                 ret = hci_dat_v1_init(hci);
  96                 if (ret)
  97                         return ret;
  98         }
  99         dat_idx = find_first_zero_bit(hci->DAT_data, hci->DAT_entries);
 100         if (dat_idx >= hci->DAT_entries)
 101                 return -ENOENT;
 102         __set_bit(dat_idx, hci->DAT_data);
 103
 104         /* default flags */
 105         dat_w0_write(dat_idx, DAT_0_SIR_REJECT | DAT_0_MR_REJECT);
 106
 107         return dat_idx;
 108 }
 109
 110 static void hci_dat_v1_free_entry(struct i3c_hci *hci, unsigned int dat_idx)
 111 {
 112         dat_w0_write(dat_idx, 0);
 113         dat_w1_write(dat_idx, 0);
 114         if (hci->DAT_data)
 115                 __clear_bit(dat_idx, hci->DAT_data);
 116 }
 117
 118 static void hci_dat_v1_set_dynamic_addr(struct i3c_hci *hci,
 119                                         unsigned int dat_idx, u8 address)
 120 {
 121         u32 dat_w0;
 122
 123         dat_w0 = dat_w0_read(dat_idx);
 124         dat_w0 &= ~(DAT_0_DYNAMIC_ADDRESS | DAT_0_DYNADDR_PARITY);
 125         dat_w0 |= FIELD_PREP(DAT_0_DYNAMIC_ADDRESS, address) |
 126                   (dynaddr_parity(address) ? DAT_0_DYNADDR_PARITY : 0);
 127         dat_w0_write(dat_idx, dat_w0);
 128 }
 129
 130 static void hci_dat_v1_set_static_addr(struct i3c_hci *hci,
 131                                        unsigned int dat_idx, u8 address)
 132 {
 133         u32 dat_w0;
 134
 135         dat_w0 = dat_w0_read(dat_idx);
 136         dat_w0 &= ~DAT_0_STATIC_ADDRESS;
 137         dat_w0 |= FIELD_PREP(DAT_0_STATIC_ADDRESS, address);
 138         dat_w0_write(dat_idx, dat_w0);
 139 }
 140
 141 static void hci_dat_v1_set_flags(struct i3c_hci *hci, unsigned int dat_idx,
 142                                  u32 w0_flags, u32 w1_flags)
 143 {
 144         u32 dat_w0, dat_w1;
 145
 146         dat_w0 = dat_w0_read(dat_idx);
 147         dat_w1 = dat_w1_read(dat_idx);
 148         dat_w0 |= w0_flags;
 149         dat_w1 |= w1_flags;
 150         dat_w0_write(dat_idx, dat_w0);
 151         dat_w1_write(dat_idx, dat_w1);
 152 }
 153
 154 static void hci_dat_v1_clear_flags(struct i3c_hci *hci, unsigned int dat_idx,
 155                                    u32 w0_flags, u32 w1_flags)
 156 {
 157         u32 dat_w0, dat_w1;
 158
 159         dat_w0 = dat_w0_read(dat_idx);
 160         dat_w1 = dat_w1_read(dat_idx);
 161         dat_w0 &= ~w0_flags;
 162         dat_w1 &= ~w1_flags;
 163         dat_w0_write(dat_idx, dat_w0);
 164         dat_w1_write(dat_idx, dat_w1);
 165 }
 166
 167 static int hci_dat_v1_get_index(struct i3c_hci *hci, u8 dev_addr)
 168 {
 169         unsigned int dat_idx;
 170         u32 dat_w0;
 171
 172         for_each_set_bit(dat_idx, hci->DAT_data, hci->DAT_entries) {
 173                 dat_w0 = dat_w0_read(dat_idx);
 174                 if (FIELD_GET(DAT_0_DYNAMIC_ADDRESS, dat_w0) == dev_addr)
 175                         return dat_idx;
 176         }
 177
 178         return -ENODEV;
 179 }
 180
 181 const struct hci_dat_ops mipi_i3c_hci_dat_v1 = {
 182         .init                   = hci_dat_v1_init,
 183         .cleanup                = hci_dat_v1_cleanup,
 184         .alloc_entry            = hci_dat_v1_alloc_entry,
 185         .free_entry             = hci_dat_v1_free_entry,
 186         .set_dynamic_addr       = hci_dat_v1_set_dynamic_addr,
 187         .set_static_addr        = hci_dat_v1_set_static_addr,
 188         .set_flags              = hci_dat_v1_set_flags,
 189         .clear_flags            = hci_dat_v1_clear_flags,
 190         .get_index              = hci_dat_v1_get_index,
 191 };