diff options
-rw-r--r-- | drivers/fsi/fsi-master-gpio.c | 86 |
1 files changed, 64 insertions, 22 deletions
diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c index 20b334f1827d..4295a46780cb 100644 --- a/drivers/fsi/fsi-master-gpio.c +++ b/drivers/fsi/fsi-master-gpio.c @@ -54,7 +54,8 @@ struct fsi_master_gpio { struct fsi_master master; struct device *dev; - spinlock_t cmd_lock; /* Lock for commands */ + struct mutex cmd_lock; /* mutex for command ordering */ + spinlock_t bit_lock; /* lock for clocking bits out */ struct gpio_desc *gpio_clk; struct gpio_desc *gpio_data; struct gpio_desc *gpio_trans; /* Voltage translator */ @@ -270,10 +271,13 @@ static int read_one_response(struct fsi_master_gpio *master, uint8_t data_size, struct fsi_gpio_msg *msgp, uint8_t *tagp) { struct fsi_gpio_msg msg; - uint8_t tag; + unsigned long flags; uint32_t crc; + uint8_t tag; int i; + spin_lock_irqsave(&master->bit_lock, flags); + /* wait for the start bit */ for (i = 0; i < FSI_GPIO_MTOE_COUNT; i++) { msg.bits = 0; @@ -286,6 +290,7 @@ static int read_one_response(struct fsi_master_gpio *master, dev_dbg(master->dev, "Master time out waiting for response\n"); fsi_master_gpio_error(master, FSI_GPIO_MTOE); + spin_unlock_irqrestore(&master->bit_lock, flags); return -EIO; } @@ -304,6 +309,8 @@ static int read_one_response(struct fsi_master_gpio *master, /* read CRC */ serial_in(master, &msg, FSI_GPIO_CRC_SIZE); + spin_unlock_irqrestore(&master->bit_lock, flags); + /* we have a whole message now; check CRC */ crc = crc4(0, 1, 1); crc = crc4(crc, msg.msg, msg.bits); @@ -324,12 +331,16 @@ static int read_one_response(struct fsi_master_gpio *master, static int issue_term(struct fsi_master_gpio *master, uint8_t slave) { struct fsi_gpio_msg cmd; + unsigned long flags; uint8_t tag; int rc; build_term_command(&cmd, slave); + + spin_lock_irqsave(&master->bit_lock, flags); serial_out(master, &cmd); echo_delay(master); + spin_unlock_irqrestore(&master->bit_lock, flags); rc = read_one_response(master, 0, NULL, &tag); if (rc < 0) { @@ -349,6 +360,7 @@ static int poll_for_response(struct fsi_master_gpio *master, { struct fsi_gpio_msg response, cmd; int busy_count = 0, rc, i; + unsigned long flags; uint8_t tag; uint8_t *data_byte = data; @@ -377,15 +389,20 @@ retry: * d-poll, not indicated in the hardware protocol * spec. < 20 clocks causes slave to hang, 21 ok. */ - clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); if (busy_count++ < FSI_GPIO_MAX_BUSY) { build_dpoll_command(&cmd, slave); + spin_lock_irqsave(&master->bit_lock, flags); + clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); serial_out(master, &cmd); echo_delay(master); + spin_unlock_irqrestore(&master->bit_lock, flags); goto retry; } dev_warn(master->dev, "ERR slave is stuck in busy state, issuing TERM\n"); + spin_lock_irqsave(&master->bit_lock, flags); + clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); + spin_unlock_irqrestore(&master->bit_lock, flags); issue_term(master, slave); rc = -EIO; break; @@ -404,27 +421,42 @@ retry: trace_fsi_master_gpio_poll_response_busy(master, busy_count); /* Clock the slave enough to be ready for next operation */ + spin_lock_irqsave(&master->bit_lock, flags); clock_zeros(master, FSI_GPIO_PRIME_SLAVE_CLOCKS); + spin_unlock_irqrestore(&master->bit_lock, flags); return rc; } -static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave, - struct fsi_gpio_msg *cmd, size_t resp_len, void *resp) +static int send_request(struct fsi_master_gpio *master, + struct fsi_gpio_msg *cmd) { unsigned long flags; - int rc; - - spin_lock_irqsave(&master->cmd_lock, flags); + spin_lock_irqsave(&master->bit_lock, flags); if (master->external_mode) { - spin_unlock_irqrestore(&master->cmd_lock, flags); + spin_unlock_irqrestore(&master->bit_lock, flags); return -EBUSY; } serial_out(master, cmd); echo_delay(master); - rc = poll_for_response(master, slave, resp_len, resp); - spin_unlock_irqrestore(&master->cmd_lock, flags); + spin_unlock_irqrestore(&master->bit_lock, flags); + + return 0; +} + +static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave, + struct fsi_gpio_msg *cmd, size_t resp_len, void *resp) +{ + int rc; + + mutex_lock(&master->cmd_lock); + + rc = send_request(master, cmd); + if (!rc) + rc = poll_for_response(master, slave, resp_len, resp); + + mutex_unlock(&master->cmd_lock); return rc; } @@ -478,11 +510,14 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) trace_fsi_master_gpio_break(master); - spin_lock_irqsave(&master->cmd_lock, flags); + mutex_lock(&master->cmd_lock); if (master->external_mode) { - spin_unlock_irqrestore(&master->cmd_lock, flags); + mutex_unlock(&master->cmd_lock); return -EBUSY; } + + spin_lock_irqsave(&master->bit_lock, flags); + set_sda_output(master, 1); sda_out(master, 1); clock_toggle(master, FSI_PRE_BREAK_CLOCKS); @@ -491,7 +526,9 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) echo_delay(master); sda_out(master, 1); clock_toggle(master, FSI_POST_BREAK_CLOCKS); - spin_unlock_irqrestore(&master->cmd_lock, flags); + + spin_unlock_irqrestore(&master->bit_lock, flags); + mutex_unlock(&master->cmd_lock); /* Wait for logic reset to take effect */ udelay(200); @@ -501,6 +538,8 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) static void fsi_master_gpio_init(struct fsi_master_gpio *master) { + unsigned long flags; + gpiod_direction_output(master->gpio_mux, 1); gpiod_direction_output(master->gpio_trans, 1); gpiod_direction_output(master->gpio_enable, 1); @@ -508,7 +547,9 @@ static void fsi_master_gpio_init(struct fsi_master_gpio *master) gpiod_direction_output(master->gpio_data, 1); /* todo: evaluate if clocks can be reduced */ + spin_lock_irqsave(&master->bit_lock, flags); clock_zeros(master, FSI_INIT_CLOCKS); + spin_unlock_irqrestore(&master->bit_lock, flags); } static void fsi_master_gpio_init_external(struct fsi_master_gpio *master) @@ -523,18 +564,17 @@ static void fsi_master_gpio_init_external(struct fsi_master_gpio *master) static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link) { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); - unsigned long flags; int rc = -EBUSY; if (link != 0) return -ENODEV; - spin_lock_irqsave(&master->cmd_lock, flags); + mutex_lock(&master->cmd_lock); if (!master->external_mode) { gpiod_set_value(master->gpio_enable, 1); rc = 0; } - spin_unlock_irqrestore(&master->cmd_lock, flags); + mutex_unlock(&master->cmd_lock); return rc; } @@ -552,7 +592,7 @@ static ssize_t external_mode_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsi_master_gpio *master = dev_get_drvdata(dev); - unsigned long flags, val; + unsigned long val; bool external_mode; int err; @@ -562,10 +602,10 @@ static ssize_t external_mode_store(struct device *dev, external_mode = !!val; - spin_lock_irqsave(&master->cmd_lock, flags); + mutex_lock(&master->cmd_lock); if (external_mode == master->external_mode) { - spin_unlock_irqrestore(&master->cmd_lock, flags); + mutex_unlock(&master->cmd_lock); return count; } @@ -574,7 +614,8 @@ static ssize_t external_mode_store(struct device *dev, fsi_master_gpio_init_external(master); else fsi_master_gpio_init(master); - spin_unlock_irqrestore(&master->cmd_lock, flags); + + mutex_unlock(&master->cmd_lock); fsi_master_rescan(&master->master); @@ -642,7 +683,8 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) master->master.send_break = fsi_master_gpio_break; master->master.link_enable = fsi_master_gpio_link_enable; platform_set_drvdata(pdev, master); - spin_lock_init(&master->cmd_lock); + spin_lock_init(&master->bit_lock); + mutex_init(&master->cmd_lock); fsi_master_gpio_init(master); |