diff options
Diffstat (limited to 'drivers/fsi')
| -rw-r--r-- | drivers/fsi/fsi-master-gpio.c | 102 |
1 files changed, 91 insertions, 11 deletions
diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c index d50ea4849377..0a6799bda294 100644 --- a/drivers/fsi/fsi-master-gpio.c +++ b/drivers/fsi/fsi-master-gpio.c @@ -28,6 +28,8 @@ #define FSI_GPIO_CMD_DPOLL 0x2 #define FSI_GPIO_CMD_TERM 0x3f #define FSI_GPIO_CMD_ABS_AR 0x4 +#define FSI_GPIO_CMD_REL_AR 0x5 +#define FSI_GPIO_CMD_SAME_AR 0x3 /* but only a 2-bit opcode... */ #define FSI_GPIO_DPOLL_CLOCKS 50 /* < 21 will cause slave to hang */ @@ -52,6 +54,8 @@ #define FSI_GPIO_MSG_RESPID_SIZE 2 #define FSI_GPIO_PRIME_SLAVE_CLOCKS 20 +#define LAST_ADDR_INVALID 0x1 + struct fsi_master_gpio { struct fsi_master master; struct device *dev; @@ -64,6 +68,7 @@ struct fsi_master_gpio { struct gpio_desc *gpio_mux; /* Mux control */ bool external_mode; bool no_delays; + uint32_t last_addr; }; #define CREATE_TRACE_POINTS @@ -205,22 +210,89 @@ static void msg_push_crc(struct fsi_gpio_msg *msg) msg_push_bits(msg, crc, 4); } +static bool check_same_address(struct fsi_master_gpio *master, int id, + uint32_t addr) +{ + /* this will also handle LAST_ADDR_INVALID */ + return master->last_addr == (((id & 0x3) << 21) | (addr & ~0x3)); +} + +static bool check_relative_address(struct fsi_master_gpio *master, int id, + uint32_t addr, uint32_t *rel_addrp) +{ + uint32_t last_addr = master->last_addr; + int32_t rel_addr; + + if (last_addr == LAST_ADDR_INVALID) + return false; + + /* We may be in 23-bit addressing mode, which uses the id as the + * top two address bits. So, if we're referencing a different ID, + * use absolute addresses. + */ + if (((last_addr >> 21) & 0x3) != id) + return false; + + /* remove the top two bits from any 23-bit addressing */ + last_addr &= (1 << 21) - 1; + + /* We know that the addresses are limited to 21 bits, so this won't + * overflow the signed rel_addr */ + rel_addr = addr - last_addr; + if (rel_addr > 255 || rel_addr < -256) + return false; + + *rel_addrp = (uint32_t)rel_addr; + + return true; +} + +static void last_address_update(struct fsi_master_gpio *master, + int id, bool valid, uint32_t addr) +{ + if (!valid) + master->last_addr = LAST_ADDR_INVALID; + else + master->last_addr = ((id & 0x3) << 21) | (addr & ~0x3); +} + /* - * Encode an Absolute Address command + * Encode an Absolute/Relative/Same Address command */ -static void build_abs_ar_command(struct fsi_gpio_msg *cmd, - uint8_t id, uint32_t addr, size_t size, const void *data) +static void build_ar_command(struct fsi_master_gpio *master, + struct fsi_gpio_msg *cmd, uint8_t id, + uint32_t addr, size_t size, const void *data) { + int i, addr_bits, opcode_bits; bool write = !!data; - uint8_t ds; - int i; + uint8_t ds, opcode; + uint32_t rel_addr; cmd->bits = 0; cmd->msg = 0; - msg_push_bits(cmd, id, 2); - msg_push_bits(cmd, FSI_GPIO_CMD_ABS_AR, 3); - msg_push_bits(cmd, write ? 0 : 1, 1); + /* we have 21 bits of address max */ + addr &= ((1 << 21) - 1); + + /* cmd opcodes are variable length - SAME_AR is only two bits */ + opcode_bits = 3; + + if (check_same_address(master, id, addr)) { + /* we still address the byte offset within the word */ + addr_bits = 2; + opcode_bits = 2; + opcode = FSI_GPIO_CMD_SAME_AR; + + } else if (check_relative_address(master, id, addr, &rel_addr)) { + /* 8 bits plus sign */ + addr_bits = 9; + addr = rel_addr; + opcode = FSI_GPIO_CMD_REL_AR; + + } else { + addr_bits = 21; + opcode = FSI_GPIO_CMD_ABS_AR; + } /* * The read/write size is encoded in the lower bits of the address @@ -237,7 +309,10 @@ static void build_abs_ar_command(struct fsi_gpio_msg *cmd, if (size == 4) addr |= 1; - msg_push_bits(cmd, addr & ((1 << 21) - 1), 21); + msg_push_bits(cmd, id, 2); + msg_push_bits(cmd, opcode, opcode_bits); + msg_push_bits(cmd, write ? 0 : 1, 1); + msg_push_bits(cmd, addr, addr_bits); msg_push_bits(cmd, ds, 1); for (i = 0; write && i < size; i++) msg_push_bits(cmd, ((uint8_t *)data)[i], 8); @@ -481,8 +556,9 @@ static int fsi_master_gpio_read(struct fsi_master *_master, int link, return -ENODEV; mutex_lock(&master->cmd_lock); - build_abs_ar_command(&cmd, id, addr, size, NULL); + build_ar_command(master, &cmd, id, addr, size, NULL); rc = fsi_master_gpio_xfer(master, id, &cmd, size, val); + last_address_update(master, id, rc == 0, addr); mutex_unlock(&master->cmd_lock); return rc; @@ -499,8 +575,9 @@ static int fsi_master_gpio_write(struct fsi_master *_master, int link, return -ENODEV; mutex_lock(&master->cmd_lock); - build_abs_ar_command(&cmd, id, addr, size, val); + build_ar_command(master, &cmd, id, addr, size, val); rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); + last_address_update(master, id, rc == 0, addr); mutex_unlock(&master->cmd_lock); return rc; @@ -519,6 +596,7 @@ static int fsi_master_gpio_term(struct fsi_master *_master, mutex_lock(&master->cmd_lock); build_term_command(&cmd, id); rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); + last_address_update(master, id, false, 0); mutex_unlock(&master->cmd_lock); return rc; @@ -552,6 +630,7 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) clock_toggle(master, FSI_POST_BREAK_CLOCKS); spin_unlock_irqrestore(&master->bit_lock, flags); + last_address_update(master, 0, false, 0); mutex_unlock(&master->cmd_lock); /* Wait for logic reset to take effect */ @@ -662,6 +741,7 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) master->dev = &pdev->dev; master->master.dev.parent = master->dev; master->master.dev.of_node = of_node_get(dev_of_node(master->dev)); + master->last_addr = LAST_ADDR_INVALID; gpio = devm_gpiod_get(&pdev->dev, "clock", 0); if (IS_ERR(gpio)) { |