Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | |
| 3 | #include <commonlib/endian.h> |
| 4 | #include <console/console.h> |
| 5 | #include <device/device.h> |
| 6 | #include <device/smbus.h> |
| 7 | |
| 8 | #include "pi608gp.h" |
| 9 | #include "chip.h" |
| 10 | |
| 11 | #define PI608GP_CMD_BLK_RD_INIT 0xba |
| 12 | #define PI608GP_CMD_BLK_RD 0xbd |
| 13 | #define PI608GP_CMD_BLK_WR 0xbe |
| 14 | #define PI608GP_SUBCMD_RD 0x04 |
| 15 | #define PI608GP_SUBCMD_WR 0x03 |
| 16 | |
| 17 | /* |
| 18 | * Only some of the available registers are implemented. |
| 19 | * For a full list, see the PI7C9X2G608GP datasheet. |
| 20 | */ |
| 21 | #define PI608GP_REG_SW_OPMODE 0x74 |
| 22 | #define PI608GP_REG_PHY_PAR1 0x78 |
| 23 | #define PI608GP_REG_TL_CSR 0x8c |
| 24 | |
| 25 | #define PI608GP_EN_4B 0x0f /* Enable all 4 data bytes in SMBus messages. */ |
| 26 | #define PI608GP_ENCODE_ERR 0xff |
| 27 | |
| 28 | static uint8_t pi608gp_encode_amp_lvl(uint32_t level_mv) |
| 29 | { |
| 30 | /* Allowed drive amplitude levels are in units of mV in range 0 to 475 mV with 25 mV |
| 31 | steps, based on Table 6-6 from the PI7C9X2G608GP datasheet. */ |
| 32 | if (level_mv > 475) { |
Jan Samek | 872e84f | 2023-05-30 10:56:30 +0200 | [diff] [blame] | 33 | printk(BIOS_ERR, "PI608GP: Drive level %u mV out of range 0 to 475 mV!", |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 34 | level_mv); |
| 35 | return PI608GP_ENCODE_ERR; |
| 36 | } |
| 37 | if (level_mv % 25 != 0) { |
Jan Samek | 872e84f | 2023-05-30 10:56:30 +0200 | [diff] [blame] | 38 | printk(BIOS_ERR, "PI608GP: Drive level %u mV not a multiple of 25!\n", |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 39 | level_mv); |
| 40 | return PI608GP_ENCODE_ERR; |
| 41 | } |
| 42 | |
| 43 | /* The encoded value is a 5-bit number representing 25 mV steps. */ |
| 44 | return (level_mv / 25) & 0x1f; |
| 45 | } |
| 46 | |
| 47 | static uint8_t pi608gp_encode_deemph_lvl(struct deemph_lvl level_mv) |
| 48 | { |
| 49 | /* Table of allowed fixed-point millivolt values, based on Table 6-8 from the |
| 50 | PI7C9X2G608GP datasheet. */ |
Jan Samek | 872e84f | 2023-05-30 10:56:30 +0200 | [diff] [blame] | 51 | const struct deemph_lvl allowed[] = { |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 52 | { 0, 0}, { 6, 0}, { 12, 5}, { 19, 0}, { 25, 0}, { 31, 0}, { 37, 5}, { 44, 0}, |
| 53 | { 50, 0}, { 56, 0}, { 62, 5}, { 69, 0}, { 75, 0}, { 81, 0}, { 87, 0}, { 94, 0}, |
| 54 | {100, 0}, {106, 0}, {112, 5}, {119, 0}, {125, 0}, {131, 0}, {137, 5}, {144, 0}, |
| 55 | {150, 0}, {156, 0}, {162, 5}, {169, 0}, {175, 0}, {181, 0}, {187, 5}, {194, 0}, |
| 56 | }; |
| 57 | |
| 58 | for (int i = 0; i < ARRAY_SIZE(allowed); i++) { |
| 59 | if (allowed[i].lvl == level_mv.lvl && allowed[i].lvl_10 == level_mv.lvl_10) |
| 60 | /* When found, the encoded value is a 5-bit number that corresponds to |
| 61 | the index in the table of allowed values above. */ |
Jan Samek | 872e84f | 2023-05-30 10:56:30 +0200 | [diff] [blame] | 62 | return i & 0x1f; |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 63 | } |
| 64 | |
Jan Samek | 872e84f | 2023-05-30 10:56:30 +0200 | [diff] [blame] | 65 | printk(BIOS_ERR, "PI608GP: Requested unsupported de-emphasis level value: %u.%u mV!\n", |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 66 | level_mv.lvl, level_mv.lvl_10); |
| 67 | return PI608GP_ENCODE_ERR; |
| 68 | } |
| 69 | |
| 70 | static enum cb_err |
| 71 | pi608gp_reg_read(struct device *dev, uint8_t port, uint32_t reg_addr, uint32_t *val) |
| 72 | { |
| 73 | int ret; |
| 74 | |
| 75 | /* |
| 76 | * Compose the SMBus message for register read init operation (from MSB to LSB): |
| 77 | * Byte 1: 7:3 = Rsvd., 2:0 = Command, |
| 78 | * Byte 2: 7:4 = Rsvd., 3:0 = Port Select[4:1], |
| 79 | * Byte 3: 7 = Port Select[0], 6 = Rsvd., 5:2 = Byte Enable, 1:0 = Reg. Addr. [11:10], |
| 80 | * Byte 4: 7:0 = Reg. Addr.[9:2] (Reg. Addr. [1:0] is fixed to 0). |
| 81 | */ |
| 82 | uint8_t buf[4] = { |
| 83 | PI608GP_SUBCMD_RD, |
| 84 | (port >> 1) & 0xf, |
| 85 | ((port & 0x1) << 7) | (PI608GP_EN_4B << 2) | ((reg_addr >> 10) & 0x3), |
| 86 | (reg_addr >> 2) & 0xff, |
| 87 | }; |
| 88 | |
| 89 | /* Initialize register read operation */ |
| 90 | ret = smbus_block_write(dev, PI608GP_CMD_BLK_RD_INIT, sizeof(buf), buf); |
| 91 | if (ret != sizeof(buf)) { |
| 92 | printk(BIOS_ERR, "PI608GP: Unable to initiate register read!\n"); |
| 93 | return CB_ERR; |
| 94 | } |
| 95 | |
| 96 | /* Perform the register read */ |
| 97 | ret = smbus_block_read(dev, PI608GP_CMD_BLK_RD, sizeof(buf), buf); |
| 98 | if (ret != sizeof(buf)) { |
| 99 | printk(BIOS_ERR, "PI608GP: Error reading register 0x%x (port %d)\n", |
| 100 | reg_addr, port); |
| 101 | return CB_ERR; |
| 102 | } |
| 103 | |
| 104 | /* Retrieve back the value from the received SMBus packet in big endian order. */ |
Jan Samek | 0acb78b | 2023-06-12 10:51:39 +0200 | [diff] [blame^] | 105 | *val = read_be32((void *)buf); |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 106 | |
| 107 | return CB_SUCCESS; |
| 108 | } |
| 109 | |
| 110 | static enum cb_err |
| 111 | pi608gp_reg_write(struct device *dev, uint8_t port, uint32_t reg_addr, uint32_t val) |
| 112 | { |
| 113 | int ret; |
| 114 | |
| 115 | /* Assemble register write command header, the same way as with read but add extra 4 |
| 116 | bytes for the value. */ |
| 117 | uint8_t buf[8] = { |
| 118 | PI608GP_SUBCMD_WR, |
| 119 | (port >> 1) & 0xf, |
| 120 | ((port & 0x1) << 7) | (PI608GP_EN_4B << 2) | ((reg_addr >> 10) & 0x3), |
| 121 | (reg_addr >> 2) & 0xff, |
| 122 | }; |
| 123 | |
| 124 | /* Insert register value to write in BE order after the header. */ |
Jan Samek | 0acb78b | 2023-06-12 10:51:39 +0200 | [diff] [blame^] | 125 | write_be32((void *)&buf[4], val); |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 126 | |
| 127 | /* Perform the register write */ |
| 128 | ret = smbus_block_write(dev, PI608GP_CMD_BLK_WR, sizeof(buf), buf); |
| 129 | if (ret != sizeof(buf)) { |
| 130 | printk(BIOS_ERR, "PI608GP: Unable to write register 0x%x\n", reg_addr); |
| 131 | return CB_ERR; |
| 132 | } |
| 133 | |
| 134 | return CB_SUCCESS; |
| 135 | } |
| 136 | |
Jan Samek | 0acb78b | 2023-06-12 10:51:39 +0200 | [diff] [blame^] | 137 | static enum cb_err |
| 138 | pi608gp_reg_update(struct device *dev, uint8_t port, uint32_t reg_addr, uint32_t and_mask, |
| 139 | uint32_t or_mask) |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 140 | { |
| 141 | uint32_t val; |
| 142 | |
| 143 | if (pi608gp_reg_read(dev, port, reg_addr, &val)) |
| 144 | return CB_ERR; |
| 145 | |
| 146 | val &= and_mask; |
| 147 | val |= or_mask; |
| 148 | |
| 149 | if (pi608gp_reg_write(dev, port, reg_addr, val)) |
| 150 | return CB_ERR; |
| 151 | |
| 152 | return CB_SUCCESS; |
| 153 | } |
| 154 | |
| 155 | static void pi608gp_init(struct device *dev) |
| 156 | { |
Jan Samek | 0acb78b | 2023-06-12 10:51:39 +0200 | [diff] [blame^] | 157 | const uint8_t port = 0; /* Only the upstream port is being configured */ |
Jan Samek | e59f18b | 2023-04-12 14:36:02 +0200 | [diff] [blame] | 158 | struct drivers_i2c_pi608gp_config *config = dev->chip_info; |
| 159 | uint8_t amp_lvl, deemph_lvl; |
| 160 | |
| 161 | /* The register values need to be encoded in a more complex way for the hardware. */ |
| 162 | amp_lvl = pi608gp_encode_amp_lvl(config->gen2_3p5_amp); |
| 163 | deemph_lvl = pi608gp_encode_deemph_lvl(config->gen2_3p5_deemph); |
| 164 | |
| 165 | /* When the de-emphasis option isn't enabled or the values incorrectly encoded, |
| 166 | don't do anything. */ |
| 167 | if (!config->gen2_3p5_enable || amp_lvl == PI608GP_ENCODE_ERR || |
| 168 | deemph_lvl == PI608GP_ENCODE_ERR) |
| 169 | return; |
| 170 | |
| 171 | /* Enable -3,5 dB de-emphasis option (P35_GEN2_MODE). */ |
| 172 | if (pi608gp_reg_update(dev, port, PI608GP_REG_TL_CSR, ~0, 1 << 31)) |
| 173 | return; |
| 174 | |
| 175 | /* Set drive amplitude level for -3,5 dB de-emphasis (bits 20:16). */ |
| 176 | if (pi608gp_reg_update(dev, port, PI608GP_REG_SW_OPMODE, ~(0x1f << 16), amp_lvl << 16)) |
| 177 | return; |
| 178 | |
| 179 | /* Set drive de-emphasis for -3,5 dB on Gen 2 (bits 25:21). */ |
| 180 | if (pi608gp_reg_update(dev, port, PI608GP_REG_PHY_PAR1, ~(0x1f << 21), deemph_lvl << 21)) |
| 181 | return; |
| 182 | } |
| 183 | |
| 184 | struct device_operations pi608gp_ops = { |
| 185 | .read_resources = noop_read_resources, |
| 186 | .set_resources = noop_set_resources, |
| 187 | .init = pi608gp_init, |
| 188 | }; |
| 189 | |
| 190 | struct chip_operations drivers_i2c_pi608gp_ops = { |
| 191 | CHIP_NAME("PI7C9X2G608GP") |
| 192 | }; |