1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2013-2021 Intel Corporation 4 * 5 * LPT/WPT IOSF sideband. 6 */ 7 8 #include <drm/drm_print.h> 9 10 #include "intel_de.h" 11 #include "intel_display_core.h" 12 #include "intel_sbi.h" 13 #include "intel_sbi_regs.h" 14 15 /* SBI access */ 16 static int intel_sbi_rw(struct intel_display *display, u16 reg, 17 enum intel_sbi_destination destination, 18 u32 *val, bool is_read) 19 { 20 u32 cmd; 21 22 lockdep_assert_held(&display->sbi.lock); 23 24 if (intel_de_wait_fw_ms(display, SBI_CTL_STAT, 25 SBI_STATUS_MASK, SBI_STATUS_READY, 100, NULL)) { 26 drm_err(display->drm, "timeout waiting for SBI to become ready\n"); 27 return -EBUSY; 28 } 29 30 intel_de_write_fw(display, SBI_ADDR, SBI_ADDR_VALUE(reg)); 31 intel_de_write_fw(display, SBI_DATA, is_read ? 0 : *val); 32 33 if (destination == SBI_ICLK) 34 cmd = SBI_CTL_DEST_ICLK | SBI_CTL_OP_CRRD; 35 else 36 cmd = SBI_CTL_DEST_MPHY | SBI_CTL_OP_IORD; 37 if (!is_read) 38 cmd |= SBI_CTL_OP_WR; 39 intel_de_write_fw(display, SBI_CTL_STAT, cmd | SBI_STATUS_BUSY); 40 41 if (intel_de_wait_fw_ms(display, SBI_CTL_STAT, 42 SBI_STATUS_MASK, SBI_STATUS_READY, 100, &cmd)) { 43 drm_err(display->drm, "timeout waiting for SBI to complete read\n"); 44 return -ETIMEDOUT; 45 } 46 47 if (cmd & SBI_RESPONSE_FAIL) { 48 drm_err(display->drm, "error during SBI read of reg %x\n", reg); 49 return -ENXIO; 50 } 51 52 if (is_read) 53 *val = intel_de_read_fw(display, SBI_DATA); 54 55 return 0; 56 } 57 58 void intel_sbi_lock(struct intel_display *display) 59 { 60 mutex_lock(&display->sbi.lock); 61 } 62 63 void intel_sbi_unlock(struct intel_display *display) 64 { 65 mutex_unlock(&display->sbi.lock); 66 } 67 68 u32 intel_sbi_read(struct intel_display *display, u16 reg, 69 enum intel_sbi_destination destination) 70 { 71 u32 result = 0; 72 73 intel_sbi_rw(display, reg, destination, &result, true); 74 75 return result; 76 } 77 78 void intel_sbi_write(struct intel_display *display, u16 reg, u32 value, 79 enum intel_sbi_destination destination) 80 { 81 intel_sbi_rw(display, reg, destination, &value, false); 82 } 83 84 void intel_sbi_init(struct intel_display *display) 85 { 86 mutex_init(&display->sbi.lock); 87 } 88 89 void intel_sbi_fini(struct intel_display *display) 90 { 91 mutex_destroy(&display->sbi.lock); 92 } 93