diff options
author | Mark Brown <broonie@linaro.org> | 2013-09-01 13:48:54 +0100 |
---|---|---|
committer | Mark Brown <broonie@linaro.org> | 2013-09-01 13:48:54 +0100 |
commit | 497cb4473a88fb18c2a773160f9328c499be7051 (patch) | |
tree | af1125059cf210eb5582ceee092063435490c26f | |
parent | afa8f0cd6c97379f4b6e5abb857e93efbcef799b (diff) | |
parent | 6a3fc31f35025a583499c0d3b1c6fc5dcf6e48ec (diff) |
Merge remote-tracking branch 'spi/topic/ep93xx' into spi-next
-rw-r--r-- | drivers/spi/spi-ep93xx.c | 353 |
1 files changed, 81 insertions, 272 deletions
diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c index cad30b8a1d7..31611f7d7be 100644 --- a/drivers/spi/spi-ep93xx.c +++ b/drivers/spi/spi-ep93xx.c @@ -26,7 +26,6 @@ #include <linux/interrupt.h> #include <linux/module.h> #include <linux/platform_device.h> -#include <linux/workqueue.h> #include <linux/sched.h> #include <linux/scatterlist.h> #include <linux/spi/spi.h> @@ -70,19 +69,13 @@ /** * struct ep93xx_spi - EP93xx SPI controller structure - * @lock: spinlock that protects concurrent accesses to fields @running, - * @current_msg and @msg_queue * @pdev: pointer to platform device * @clk: clock for the controller * @regs_base: pointer to ioremap()'d registers * @sspdr_phys: physical address of the SSPDR register * @min_rate: minimum clock rate (in Hz) supported by the controller * @max_rate: maximum clock rate (in Hz) supported by the controller - * @running: is the queue running - * @wq: workqueue used by the driver - * @msg_work: work that is queued for the driver * @wait: wait here until given transfer is completed - * @msg_queue: queue for the messages * @current_msg: message that is currently processed (or %NULL if none) * @tx: current byte in transfer to transmit * @rx: current byte in transfer to receive @@ -96,30 +89,15 @@ * @tx_sgt: sg table for TX transfers * @zeropage: dummy page used as RX buffer when only TX buffer is passed in by * the client - * - * This structure holds EP93xx SPI controller specific information. When - * @running is %true, driver accepts transfer requests from protocol drivers. - * @current_msg is used to hold pointer to the message that is currently - * processed. If @current_msg is %NULL, it means that no processing is going - * on. - * - * Most of the fields are only written once and they can be accessed without - * taking the @lock. Fields that are accessed concurrently are: @current_msg, - * @running, and @msg_queue. */ struct ep93xx_spi { - spinlock_t lock; const struct platform_device *pdev; struct clk *clk; void __iomem *regs_base; unsigned long sspdr_phys; unsigned long min_rate; unsigned long max_rate; - bool running; - struct workqueue_struct *wq; - struct work_struct msg_work; struct completion wait; - struct list_head msg_queue; struct spi_message *current_msg; size_t tx; size_t rx; @@ -136,50 +114,36 @@ struct ep93xx_spi { /** * struct ep93xx_spi_chip - SPI device hardware settings * @spi: back pointer to the SPI device - * @rate: max rate in hz this chip supports - * @div_cpsr: cpsr (pre-scaler) divider - * @div_scr: scr divider - * @dss: bits per word (4 - 16 bits) * @ops: private chip operations - * - * This structure is used to store hardware register specific settings for each - * SPI device. Settings are written to hardware by function - * ep93xx_spi_chip_setup(). */ struct ep93xx_spi_chip { const struct spi_device *spi; - unsigned long rate; - u8 div_cpsr; - u8 div_scr; - u8 dss; struct ep93xx_spi_chip_ops *ops; }; /* converts bits per word to CR0.DSS value */ #define bits_per_word_to_dss(bpw) ((bpw) - 1) -static inline void -ep93xx_spi_write_u8(const struct ep93xx_spi *espi, u16 reg, u8 value) +static void ep93xx_spi_write_u8(const struct ep93xx_spi *espi, + u16 reg, u8 value) { - __raw_writeb(value, espi->regs_base + reg); + writeb(value, espi->regs_base + reg); } -static inline u8 -ep93xx_spi_read_u8(const struct ep93xx_spi *spi, u16 reg) +static u8 ep93xx_spi_read_u8(const struct ep93xx_spi *spi, u16 reg) { - return __raw_readb(spi->regs_base + reg); + return readb(spi->regs_base + reg); } -static inline void -ep93xx_spi_write_u16(const struct ep93xx_spi *espi, u16 reg, u16 value) +static void ep93xx_spi_write_u16(const struct ep93xx_spi *espi, + u16 reg, u16 value) { - __raw_writew(value, espi->regs_base + reg); + writew(value, espi->regs_base + reg); } -static inline u16 -ep93xx_spi_read_u16(const struct ep93xx_spi *spi, u16 reg) +static u16 ep93xx_spi_read_u16(const struct ep93xx_spi *spi, u16 reg) { - return __raw_readw(spi->regs_base + reg); + return readw(spi->regs_base + reg); } static int ep93xx_spi_enable(const struct ep93xx_spi *espi) @@ -230,17 +194,13 @@ static void ep93xx_spi_disable_interrupts(const struct ep93xx_spi *espi) /** * ep93xx_spi_calc_divisors() - calculates SPI clock divisors * @espi: ep93xx SPI controller struct - * @chip: divisors are calculated for this chip * @rate: desired SPI output clock rate - * - * Function calculates cpsr (clock pre-scaler) and scr divisors based on - * given @rate and places them to @chip->div_cpsr and @chip->div_scr. If, - * for some reason, divisors cannot be calculated nothing is stored and - * %-EINVAL is returned. + * @div_cpsr: pointer to return the cpsr (pre-scaler) divider + * @div_scr: pointer to return the scr divider */ static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi, - struct ep93xx_spi_chip *chip, - unsigned long rate) + unsigned long rate, + u8 *div_cpsr, u8 *div_scr) { unsigned long spi_clk_rate = clk_get_rate(espi->clk); int cpsr, scr; @@ -248,7 +208,7 @@ static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi, /* * Make sure that max value is between values supported by the * controller. Note that minimum value is already checked in - * ep93xx_spi_transfer(). + * ep93xx_spi_transfer_one_message(). */ rate = clamp(rate, espi->min_rate, espi->max_rate); @@ -263,8 +223,8 @@ static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi, for (cpsr = 2; cpsr <= 254; cpsr += 2) { for (scr = 0; scr <= 255; scr++) { if ((spi_clk_rate / (cpsr * (scr + 1))) <= rate) { - chip->div_scr = (u8)scr; - chip->div_cpsr = (u8)cpsr; + *div_scr = (u8)scr; + *div_cpsr = (u8)cpsr; return 0; } } @@ -319,73 +279,11 @@ static int ep93xx_spi_setup(struct spi_device *spi) spi_set_ctldata(spi, chip); } - if (spi->max_speed_hz != chip->rate) { - int err; - - err = ep93xx_spi_calc_divisors(espi, chip, spi->max_speed_hz); - if (err != 0) { - spi_set_ctldata(spi, NULL); - kfree(chip); - return err; - } - chip->rate = spi->max_speed_hz; - } - - chip->dss = bits_per_word_to_dss(spi->bits_per_word); - ep93xx_spi_cs_control(spi, false); return 0; } /** - * ep93xx_spi_transfer() - queue message to be transferred - * @spi: target SPI device - * @msg: message to be transferred - * - * This function is called by SPI device drivers when they are going to transfer - * a new message. It simply puts the message in the queue and schedules - * workqueue to perform the actual transfer later on. - * - * Returns %0 on success and negative error in case of failure. - */ -static int ep93xx_spi_transfer(struct spi_device *spi, struct spi_message *msg) -{ - struct ep93xx_spi *espi = spi_master_get_devdata(spi->master); - struct spi_transfer *t; - unsigned long flags; - - if (!msg || !msg->complete) - return -EINVAL; - - /* first validate each transfer */ - list_for_each_entry(t, &msg->transfers, transfer_list) { - if (t->speed_hz && t->speed_hz < espi->min_rate) - return -EINVAL; - } - - /* - * Now that we own the message, let's initialize it so that it is - * suitable for us. We use @msg->status to signal whether there was - * error in transfer and @msg->state is used to hold pointer to the - * current transfer (or %NULL if no active current transfer). - */ - msg->state = NULL; - msg->status = 0; - msg->actual_length = 0; - - spin_lock_irqsave(&espi->lock, flags); - if (!espi->running) { - spin_unlock_irqrestore(&espi->lock, flags); - return -ESHUTDOWN; - } - list_add_tail(&msg->queue, &espi->msg_queue); - queue_work(espi->wq, &espi->msg_work); - spin_unlock_irqrestore(&espi->lock, flags); - - return 0; -} - -/** * ep93xx_spi_cleanup() - cleans up master controller specific state * @spi: SPI device to cleanup * @@ -409,39 +307,40 @@ static void ep93xx_spi_cleanup(struct spi_device *spi) * ep93xx_spi_chip_setup() - configures hardware according to given @chip * @espi: ep93xx SPI controller struct * @chip: chip specific settings - * - * This function sets up the actual hardware registers with settings given in - * @chip. Note that no validation is done so make sure that callers validate - * settings before calling this. + * @speed_hz: transfer speed + * @bits_per_word: transfer bits_per_word */ -static void ep93xx_spi_chip_setup(const struct ep93xx_spi *espi, - const struct ep93xx_spi_chip *chip) +static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi, + const struct ep93xx_spi_chip *chip, + u32 speed_hz, u8 bits_per_word) { + u8 dss = bits_per_word_to_dss(bits_per_word); + u8 div_cpsr = 0; + u8 div_scr = 0; u16 cr0; + int err; - cr0 = chip->div_scr << SSPCR0_SCR_SHIFT; + err = ep93xx_spi_calc_divisors(espi, speed_hz, &div_cpsr, &div_scr); + if (err) + return err; + + cr0 = div_scr << SSPCR0_SCR_SHIFT; cr0 |= (chip->spi->mode & (SPI_CPHA|SPI_CPOL)) << SSPCR0_MODE_SHIFT; - cr0 |= chip->dss; + cr0 |= dss; dev_dbg(&espi->pdev->dev, "setup: mode %d, cpsr %d, scr %d, dss %d\n", - chip->spi->mode, chip->div_cpsr, chip->div_scr, chip->dss); + chip->spi->mode, div_cpsr, div_scr, dss); dev_dbg(&espi->pdev->dev, "setup: cr0 %#x", cr0); - ep93xx_spi_write_u8(espi, SSPCPSR, chip->div_cpsr); + ep93xx_spi_write_u8(espi, SSPCPSR, div_cpsr); ep93xx_spi_write_u16(espi, SSPCR0, cr0); -} - -static inline int bits_per_word(const struct ep93xx_spi *espi) -{ - struct spi_message *msg = espi->current_msg; - struct spi_transfer *t = msg->state; - return t->bits_per_word; + return 0; } static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t) { - if (bits_per_word(espi) > 8) { + if (t->bits_per_word > 8) { u16 tx_val = 0; if (t->tx_buf) @@ -460,7 +359,7 @@ static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t) static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t) { - if (bits_per_word(espi) > 8) { + if (t->bits_per_word > 8) { u16 rx_val; rx_val = ep93xx_spi_read_u16(espi, SSPDR); @@ -546,7 +445,7 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir) size_t len = t->len; int i, ret, nents; - if (bits_per_word(espi) > 8) + if (t->bits_per_word > 8) buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; else buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; @@ -610,7 +509,7 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir) } if (WARN_ON(len)) { - dev_warn(&espi->pdev->dev, "len = %d expected 0!", len); + dev_warn(&espi->pdev->dev, "len = %zu expected 0!", len); return ERR_PTR(-EINVAL); } @@ -708,37 +607,16 @@ static void ep93xx_spi_process_transfer(struct ep93xx_spi *espi, struct spi_transfer *t) { struct ep93xx_spi_chip *chip = spi_get_ctldata(msg->spi); + int err; msg->state = t; - /* - * Handle any transfer specific settings if needed. We use - * temporary chip settings here and restore original later when - * the transfer is finished. - */ - if (t->speed_hz || t->bits_per_word) { - struct ep93xx_spi_chip tmp_chip = *chip; - - if (t->speed_hz) { - int err; - - err = ep93xx_spi_calc_divisors(espi, &tmp_chip, - t->speed_hz); - if (err) { - dev_err(&espi->pdev->dev, - "failed to adjust speed\n"); - msg->status = err; - return; - } - } - - if (t->bits_per_word) - tmp_chip.dss = bits_per_word_to_dss(t->bits_per_word); - - /* - * Set up temporary new hw settings for this transfer. - */ - ep93xx_spi_chip_setup(espi, &tmp_chip); + err = ep93xx_spi_chip_setup(espi, chip, t->speed_hz, t->bits_per_word); + if (err) { + dev_err(&espi->pdev->dev, + "failed to setup chip for transfer\n"); + msg->status = err; + return; } espi->rx = 0; @@ -783,9 +661,6 @@ static void ep93xx_spi_process_transfer(struct ep93xx_spi *espi, ep93xx_spi_cs_control(msg->spi, true); } } - - if (t->speed_hz || t->bits_per_word) - ep93xx_spi_chip_setup(espi, chip); } /* @@ -838,10 +713,8 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi, espi->fifo_level = 0; /* - * Update SPI controller registers according to spi device and assert - * the chipselect. + * Assert the chipselect. */ - ep93xx_spi_chip_setup(espi, spi_get_ctldata(msg->spi)); ep93xx_spi_cs_control(msg->spi, true); list_for_each_entry(t, &msg->transfers, transfer_list) { @@ -858,50 +731,29 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi, ep93xx_spi_disable(espi); } -#define work_to_espi(work) (container_of((work), struct ep93xx_spi, msg_work)) - -/** - * ep93xx_spi_work() - EP93xx SPI workqueue worker function - * @work: work struct - * - * Workqueue worker function. This function is called when there are new - * SPI messages to be processed. Message is taken out from the queue and then - * passed to ep93xx_spi_process_message(). - * - * After message is transferred, protocol driver is notified by calling - * @msg->complete(). In case of error, @msg->status is set to negative error - * number, otherwise it contains zero (and @msg->actual_length is updated). - */ -static void ep93xx_spi_work(struct work_struct *work) +static int ep93xx_spi_transfer_one_message(struct spi_master *master, + struct spi_message *msg) { - struct ep93xx_spi *espi = work_to_espi(work); - struct spi_message *msg; + struct ep93xx_spi *espi = spi_master_get_devdata(master); + struct spi_transfer *t; - spin_lock_irq(&espi->lock); - if (!espi->running || espi->current_msg || - list_empty(&espi->msg_queue)) { - spin_unlock_irq(&espi->lock); - return; + /* first validate each transfer */ + list_for_each_entry(t, &msg->transfers, transfer_list) { + if (t->speed_hz < espi->min_rate) + return -EINVAL; } - msg = list_first_entry(&espi->msg_queue, struct spi_message, queue); - list_del_init(&msg->queue); - espi->current_msg = msg; - spin_unlock_irq(&espi->lock); - ep93xx_spi_process_message(espi, msg); + msg->state = NULL; + msg->status = 0; + msg->actual_length = 0; - /* - * Update the current message and re-schedule ourselves if there are - * more messages in the queue. - */ - spin_lock_irq(&espi->lock); + espi->current_msg = msg; + ep93xx_spi_process_message(espi, msg); espi->current_msg = NULL; - if (espi->running && !list_empty(&espi->msg_queue)) - queue_work(espi->wq, &espi->msg_work); - spin_unlock_irq(&espi->lock); - /* notify the protocol driver that we are done with this message */ - msg->complete(msg->context); + spi_finalize_current_message(master); + + return 0; } static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id) @@ -1024,14 +876,24 @@ static int ep93xx_spi_probe(struct platform_device *pdev) info = pdev->dev.platform_data; + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "failed to get irq resources\n"); + return -EBUSY; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "unable to get iomem resource\n"); + return -ENODEV; + } + master = spi_alloc_master(&pdev->dev, sizeof(*espi)); - if (!master) { - dev_err(&pdev->dev, "failed to allocate spi master\n"); + if (!master) return -ENOMEM; - } master->setup = ep93xx_spi_setup; - master->transfer = ep93xx_spi_transfer; + master->transfer_one_message = ep93xx_spi_transfer_one_message; master->cleanup = ep93xx_spi_cleanup; master->bus_num = pdev->id; master->num_chipselect = info->num_chipselect; @@ -1042,14 +904,13 @@ static int ep93xx_spi_probe(struct platform_device *pdev) espi = spi_master_get_devdata(master); - espi->clk = clk_get(&pdev->dev, NULL); + espi->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(espi->clk)) { dev_err(&pdev->dev, "unable to get spi clock\n"); error = PTR_ERR(espi->clk); goto fail_release_master; } - spin_lock_init(&espi->lock); init_completion(&espi->wait); /* @@ -1060,55 +921,31 @@ static int ep93xx_spi_probe(struct platform_device *pdev) espi->min_rate = clk_get_rate(espi->clk) / (254 * 256); espi->pdev = pdev; - irq = platform_get_irq(pdev, 0); - if (irq < 0) { - error = -EBUSY; - dev_err(&pdev->dev, "failed to get irq resources\n"); - goto fail_put_clock; - } - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) { - dev_err(&pdev->dev, "unable to get iomem resource\n"); - error = -ENODEV; - goto fail_put_clock; - } - espi->sspdr_phys = res->start + SSPDR; espi->regs_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(espi->regs_base)) { error = PTR_ERR(espi->regs_base); - goto fail_put_clock; + goto fail_release_master; } error = devm_request_irq(&pdev->dev, irq, ep93xx_spi_interrupt, 0, "ep93xx-spi", espi); if (error) { dev_err(&pdev->dev, "failed to request irq\n"); - goto fail_put_clock; + goto fail_release_master; } if (info->use_dma && ep93xx_spi_setup_dma(espi)) dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n"); - espi->wq = create_singlethread_workqueue("ep93xx_spid"); - if (!espi->wq) { - dev_err(&pdev->dev, "unable to create workqueue\n"); - error = -ENOMEM; - goto fail_free_dma; - } - INIT_WORK(&espi->msg_work, ep93xx_spi_work); - INIT_LIST_HEAD(&espi->msg_queue); - espi->running = true; - /* make sure that the hardware is disabled */ ep93xx_spi_write_u8(espi, SSPCR1, 0); error = spi_register_master(master); if (error) { dev_err(&pdev->dev, "failed to register SPI master\n"); - goto fail_free_queue; + goto fail_free_dma; } dev_info(&pdev->dev, "EP93xx SPI Controller at 0x%08lx irq %d\n", @@ -1116,12 +953,8 @@ static int ep93xx_spi_probe(struct platform_device *pdev) return 0; -fail_free_queue: - destroy_workqueue(espi->wq); fail_free_dma: ep93xx_spi_release_dma(espi); -fail_put_clock: - clk_put(espi->clk); fail_release_master: spi_master_put(master); @@ -1133,31 +966,7 @@ static int ep93xx_spi_remove(struct platform_device *pdev) struct spi_master *master = platform_get_drvdata(pdev); struct ep93xx_spi *espi = spi_master_get_devdata(master); - spin_lock_irq(&espi->lock); - espi->running = false; - spin_unlock_irq(&espi->lock); - - destroy_workqueue(espi->wq); - - /* - * Complete remaining messages with %-ESHUTDOWN status. - */ - spin_lock_irq(&espi->lock); - while (!list_empty(&espi->msg_queue)) { - struct spi_message *msg; - - msg = list_first_entry(&espi->msg_queue, - struct spi_message, queue); - list_del_init(&msg->queue); - msg->status = -ESHUTDOWN; - spin_unlock_irq(&espi->lock); - msg->complete(msg->context); - spin_lock_irq(&espi->lock); - } - spin_unlock_irq(&espi->lock); - ep93xx_spi_release_dma(espi); - clk_put(espi->clk); spi_unregister_master(master); return 0; |