diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_dw.c')
-rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 411 |
1 files changed, 283 insertions, 128 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index aab3cccc6789..7db51781289e 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -9,49 +9,62 @@ * LCR is written whilst busy. If it is, then a busy detect interrupt is * raised, the LCR needs to be rewritten and the uart status register read. */ +#include <linux/acpi.h> +#include <linux/clk.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/io.h> +#include <linux/mod_devicetable.h> #include <linux/module.h> -#include <linux/serial_8250.h> -#include <linux/serial_reg.h> +#include <linux/notifier.h> #include <linux/of.h> -#include <linux/of_irq.h> -#include <linux/of_platform.h> #include <linux/platform_device.h> -#include <linux/slab.h> -#include <linux/acpi.h> -#include <linux/clk.h> -#include <linux/reset.h> #include <linux/pm_runtime.h> +#include <linux/property.h> +#include <linux/reset.h> +#include <linux/slab.h> +#include <linux/workqueue.h> #include <asm/byteorder.h> +#include <linux/serial_8250.h> +#include <linux/serial_reg.h> + #include "8250_dwlib.h" /* Offsets for the DesignWare specific registers */ #define DW_UART_USR 0x1f /* UART Status Register */ +#define DW_UART_DMASA 0xa8 /* DMA Software Ack */ + +#define OCTEON_UART_USR 0x27 /* UART Status Register */ + +#define RZN1_UART_TDMACR 0x10c /* DMA Control Register Transmit Mode */ +#define RZN1_UART_RDMACR 0x110 /* DMA Control Register Receive Mode */ /* DesignWare specific register fields */ #define DW_UART_MCR_SIRE BIT(6) -struct dw8250_data { - struct dw8250_port_data data; +/* Renesas specific register fields */ +#define RZN1_UART_xDMACR_DMA_EN BIT(0) +#define RZN1_UART_xDMACR_1_WORD_BURST (0 << 1) +#define RZN1_UART_xDMACR_4_WORD_BURST (1 << 1) +#define RZN1_UART_xDMACR_8_WORD_BURST (2 << 1) +#define RZN1_UART_xDMACR_BLK_SZ(x) ((x) << 3) - u8 usr_reg; - int msr_mask_on; - int msr_mask_off; - struct clk *clk; - struct clk *pclk; - struct reset_control *rst; +/* Quirks */ +#define DW_UART_QUIRK_OCTEON BIT(0) +#define DW_UART_QUIRK_ARMADA_38X BIT(1) +#define DW_UART_QUIRK_SKIP_SET_RATE BIT(2) +#define DW_UART_QUIRK_IS_DMA_FC BIT(3) - unsigned int skip_autocfg:1; - unsigned int uart_16550_compatible:1; -}; +static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb) +{ + return container_of(nb, struct dw8250_data, clk_notifier); +} -static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data) +static inline struct dw8250_data *work_to_dw8250_data(struct work_struct *work) { - return container_of(data, struct dw8250_data, data); + return container_of(work, struct dw8250_data, clk_work); } static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value) @@ -70,8 +83,21 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value) static void dw8250_force_idle(struct uart_port *p) { struct uart_8250_port *up = up_to_u8250p(p); + unsigned int lsr; serial8250_clear_and_reinit_fifos(up); + + /* + * With PSLVERR_RESP_EN parameter set to 1, the device generates an + * error response when an attempt to read an empty RBR with FIFO + * enabled. + */ + if (up->fcr & UART_FCR_ENABLE_FIFO) { + lsr = p->serial_in(p, UART_LSR); + if (!(lsr & UART_LSR_DR)) + return; + } + (void)p->serial_in(p, UART_RX); } @@ -110,12 +136,15 @@ static void dw8250_check_lcr(struct uart_port *p, int value) /* Returns once the transmitter is empty or we run out of retries */ static void dw8250_tx_wait_empty(struct uart_port *p) { + struct uart_8250_port *up = up_to_u8250p(p); unsigned int tries = 20000; unsigned int delay_threshold = tries - 1000; unsigned int lsr; while (tries--) { lsr = readb (p->membase + (UART_LSR << p->regshift)); + up->lsr_saved_flags |= lsr & up->lsr_save_mask; + if (lsr & UART_LSR_TEMT) break; @@ -128,29 +157,23 @@ static void dw8250_tx_wait_empty(struct uart_port *p) } } -static void dw8250_serial_out38x(struct uart_port *p, int offset, int value) +static void dw8250_serial_out(struct uart_port *p, int offset, int value) { struct dw8250_data *d = to_dw8250_data(p->private_data); - /* Allow the TX to drain before we reconfigure */ - if (offset == UART_LCR) - dw8250_tx_wait_empty(p); - writeb(value, p->membase + (offset << p->regshift)); if (offset == UART_LCR && !d->uart_16550_compatible) dw8250_check_lcr(p, value); } - -static void dw8250_serial_out(struct uart_port *p, int offset, int value) +static void dw8250_serial_out38x(struct uart_port *p, int offset, int value) { - struct dw8250_data *d = to_dw8250_data(p->private_data); - - writeb(value, p->membase + (offset << p->regshift)); + /* Allow the TX to drain before we reconfigure */ + if (offset == UART_LCR) + dw8250_tx_wait_empty(p); - if (offset == UART_LCR && !d->uart_16550_compatible) - dw8250_check_lcr(p, value); + dw8250_serial_out(p, offset, value); } static unsigned int dw8250_serial_in(struct uart_port *p, int offset) @@ -224,6 +247,8 @@ static int dw8250_handle_irq(struct uart_port *p) struct uart_8250_port *up = up_to_u8250p(p); struct dw8250_data *d = to_dw8250_data(p->private_data); unsigned int iir = p->serial_in(p, UART_IIR); + bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT; + unsigned int quirks = d->pdata->quirks; unsigned int status; unsigned long flags; @@ -237,9 +262,9 @@ static int dw8250_handle_irq(struct uart_port *p) * This problem has only been observed so far when not in DMA mode * so we limit the workaround only to non-DMA mode. */ - if (!up->dma && ((iir & 0x3f) == UART_IIR_RX_TIMEOUT)) { + if (!up->dma && rx_timeout) { spin_lock_irqsave(&p->lock, flags); - status = p->serial_in(p, UART_LSR); + status = serial_lsr_in(up); if (!(status & (UART_LSR_DR | UART_LSR_BI))) (void) p->serial_in(p, UART_RX); @@ -247,12 +272,24 @@ static int dw8250_handle_irq(struct uart_port *p) spin_unlock_irqrestore(&p->lock, flags); } + /* Manually stop the Rx DMA transfer when acting as flow controller */ + if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) { + spin_lock_irqsave(&p->lock, flags); + status = serial_lsr_in(up); + spin_unlock_irqrestore(&p->lock, flags); + + if (status & (UART_LSR_DR | UART_LSR_BI)) { + dw8250_writel_ext(p, RZN1_UART_RDMACR, 0); + dw8250_writel_ext(p, DW_UART_DMASA, 1); + } + } + if (serial8250_handle_irq(p, iir)) return 1; if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) { /* Clear the USR */ - (void)p->serial_in(p, d->usr_reg); + (void)p->serial_in(p, d->pdata->usr_reg); return 1; } @@ -260,6 +297,46 @@ static int dw8250_handle_irq(struct uart_port *p) return 0; } +static void dw8250_clk_work_cb(struct work_struct *work) +{ + struct dw8250_data *d = work_to_dw8250_data(work); + struct uart_8250_port *up; + unsigned long rate; + + rate = clk_get_rate(d->clk); + if (rate <= 0) + return; + + up = serial8250_get_port(d->data.line); + + serial8250_update_uartclk(&up->port, rate); +} + +static int dw8250_clk_notifier_cb(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct dw8250_data *d = clk_to_dw8250_data(nb); + + /* + * We have no choice but to defer the uartclk update due to two + * deadlocks. First one is caused by a recursive mutex lock which + * happens when clk_set_rate() is called from dw8250_set_termios(). + * Second deadlock is more tricky and is caused by an inverted order of + * the clk and tty-port mutexes lock. It happens if clock rate change + * is requested asynchronously while set_termios() is executed between + * tty-port mutex lock and clk_set_rate() function invocation and + * vise-versa. Anyway if we didn't have the reference clock alteration + * in the dw8250_set_termios() method we wouldn't have needed this + * deferred event handling complication. + */ + if (event == POST_RATE_CHANGE) { + queue_work(system_unbound_wq, &d->clk_work); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + static void dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old) { @@ -273,34 +350,27 @@ dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old) } static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, - struct ktermios *old) + const struct ktermios *old) { - unsigned int baud = tty_termios_baud_rate(termios); + unsigned long newrate = tty_termios_baud_rate(termios) * 16; struct dw8250_data *d = to_dw8250_data(p->private_data); long rate; int ret; clk_disable_unprepare(d->clk); - rate = clk_round_rate(d->clk, baud * 16); - if (rate < 0) - ret = rate; - else if (rate == 0) - ret = -ENOENT; - else - ret = clk_set_rate(d->clk, rate); + rate = clk_round_rate(d->clk, newrate); + if (rate > 0) { + /* + * Note that any clock-notifer worker will block in + * serial8250_update_uartclk() until we are done. + */ + ret = clk_set_rate(d->clk, newrate); + if (!ret) + p->uartclk = rate; + } clk_prepare_enable(d->clk); - if (ret) - goto out; - - p->uartclk = rate; - -out: - p->status &= ~UPSTAT_AUTOCTS; - if (termios->c_cflag & CRTSCTS) - p->status |= UPSTAT_AUTOCTS; - - serial8250_do_set_termios(p, termios, old); + dw8250_do_set_termios(p, termios, old); } static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios) @@ -337,10 +407,48 @@ static bool dw8250_idma_filter(struct dma_chan *chan, void *param) return param == chan->device->dev; } +static u32 dw8250_rzn1_get_dmacr_burst(int max_burst) +{ + if (max_burst >= 8) + return RZN1_UART_xDMACR_8_WORD_BURST; + else if (max_burst >= 4) + return RZN1_UART_xDMACR_4_WORD_BURST; + else + return RZN1_UART_xDMACR_1_WORD_BURST; +} + +static void dw8250_prepare_tx_dma(struct uart_8250_port *p) +{ + struct uart_port *up = &p->port; + struct uart_8250_dma *dma = p->dma; + u32 val; + + dw8250_writel_ext(up, RZN1_UART_TDMACR, 0); + val = dw8250_rzn1_get_dmacr_burst(dma->txconf.dst_maxburst) | + RZN1_UART_xDMACR_BLK_SZ(dma->tx_size) | + RZN1_UART_xDMACR_DMA_EN; + dw8250_writel_ext(up, RZN1_UART_TDMACR, val); +} + +static void dw8250_prepare_rx_dma(struct uart_8250_port *p) +{ + struct uart_port *up = &p->port; + struct uart_8250_dma *dma = p->dma; + u32 val; + + dw8250_writel_ext(up, RZN1_UART_RDMACR, 0); + val = dw8250_rzn1_get_dmacr_burst(dma->rxconf.src_maxburst) | + RZN1_UART_xDMACR_BLK_SZ(dma->rx_size) | + RZN1_UART_xDMACR_DMA_EN; + dw8250_writel_ext(up, RZN1_UART_RDMACR, val); +} + static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data) { - if (p->dev->of_node) { - struct device_node *np = p->dev->of_node; + struct device_node *np = p->dev->of_node; + + if (np) { + unsigned int quirks = data->pdata->quirks; int id; /* get index of serial line, if found in DT aliases */ @@ -348,22 +456,31 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data) if (id >= 0) p->line = id; #ifdef CONFIG_64BIT - if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) { + if (quirks & DW_UART_QUIRK_OCTEON) { p->serial_in = dw8250_serial_inq; p->serial_out = dw8250_serial_outq; p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE; p->type = PORT_OCTEON; - data->usr_reg = 0x27; data->skip_autocfg = true; } #endif - if (of_device_is_big_endian(p->dev->of_node)) { + + if (of_device_is_big_endian(np)) { p->iotype = UPIO_MEM32BE; p->serial_in = dw8250_serial_in32be; p->serial_out = dw8250_serial_out32be; } - if (of_device_is_compatible(np, "marvell,armada-38x-uart")) + + if (quirks & DW_UART_QUIRK_ARMADA_38X) p->serial_out = dw8250_serial_out38x; + if (quirks & DW_UART_QUIRK_SKIP_SET_RATE) + p->set_termios = dw8250_do_set_termios; + if (quirks & DW_UART_QUIRK_IS_DMA_FC) { + data->data.dma.txconf.device_fc = 1; + data->data.dma.rxconf.device_fc = 1; + data->data.dma.prepare_tx_dma = dw8250_prepare_tx_dma; + data->data.dma.prepare_rx_dma = dw8250_prepare_rx_dma; + } } else if (acpi_dev_present("APMC0D08", NULL, -1)) { p->iotype = UPIO_MEM32; @@ -381,21 +498,30 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data) } } +static void dw8250_clk_disable_unprepare(void *data) +{ + clk_disable_unprepare(data); +} + +static void dw8250_reset_control_assert(void *data) +{ + reset_control_assert(data); +} + static int dw8250_probe(struct platform_device *pdev) { struct uart_8250_port uart = {}, *up = &uart; - struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); struct uart_port *p = &up->port; struct device *dev = &pdev->dev; struct dw8250_data *data; + struct resource *regs; int irq; int err; u32 val; - if (!regs) { - dev_err(dev, "no registers defined\n"); - return -EINVAL; - } + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) + return dev_err_probe(dev, -EINVAL, "no registers defined\n"); irq = platform_get_irq(pdev, 0); if (irq < 0) @@ -424,7 +550,7 @@ static int dw8250_probe(struct platform_device *pdev) return -ENOMEM; data->data.dma.fn = dw8250_fallback_dma_filter; - data->usr_reg = DW_UART_USR; + data->pdata = device_get_match_data(p->dev); p->private_data = &data->data; data->uart_16550_compatible = device_property_read_bool(dev, @@ -475,39 +601,46 @@ static int dw8250_probe(struct platform_device *pdev) if (IS_ERR(data->clk)) return PTR_ERR(data->clk); + INIT_WORK(&data->clk_work, dw8250_clk_work_cb); + data->clk_notifier.notifier_call = dw8250_clk_notifier_cb; + err = clk_prepare_enable(data->clk); if (err) - dev_warn(dev, "could not enable optional baudclk: %d\n", err); + return dev_err_probe(dev, err, "could not enable optional baudclk\n"); + + err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->clk); + if (err) + return err; if (data->clk) p->uartclk = clk_get_rate(data->clk); /* If no clock rate is defined, fail. */ - if (!p->uartclk) { - dev_err(dev, "clock rate not defined\n"); - err = -EINVAL; - goto err_clk; - } + if (!p->uartclk) + return dev_err_probe(dev, -EINVAL, "clock rate not defined\n"); data->pclk = devm_clk_get_optional(dev, "apb_pclk"); - if (IS_ERR(data->pclk)) { - err = PTR_ERR(data->pclk); - goto err_clk; - } + if (IS_ERR(data->pclk)) + return PTR_ERR(data->pclk); err = clk_prepare_enable(data->pclk); - if (err) { - dev_err(dev, "could not enable apb_pclk\n"); - goto err_clk; - } + if (err) + return dev_err_probe(dev, err, "could not enable apb_pclk\n"); + + err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->pclk); + if (err) + return err; data->rst = devm_reset_control_get_optional_exclusive(dev, NULL); - if (IS_ERR(data->rst)) { - err = PTR_ERR(data->rst); - goto err_pclk; - } + if (IS_ERR(data->rst)) + return PTR_ERR(data->rst); + reset_control_deassert(data->rst); + err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst); + if (err) + return err; + dw8250_quirks(p, data); /* If the Busy Functionality is not implemented, don't handle it */ @@ -525,9 +658,19 @@ static int dw8250_probe(struct platform_device *pdev) } data->data.line = serial8250_register_8250_port(up); - if (data->data.line < 0) { - err = data->data.line; - goto err_reset; + if (data->data.line < 0) + return data->data.line; + + /* + * Some platforms may provide a reference clock shared between several + * devices. In this case any clock state change must be known to the + * UART port at least post factum. + */ + if (data->clk) { + err = clk_notifier_register(data->clk, &data->clk_notifier); + if (err) + return dev_err_probe(dev, err, "Failed to set the clock notifier\n"); + queue_work(system_unbound_wq, &data->clk_work); } platform_set_drvdata(pdev, data); @@ -536,17 +679,6 @@ static int dw8250_probe(struct platform_device *pdev) pm_runtime_enable(dev); return 0; - -err_reset: - reset_control_assert(data->rst); - -err_pclk: - clk_disable_unprepare(data->pclk); - -err_clk: - clk_disable_unprepare(data->clk); - - return err; } static int dw8250_remove(struct platform_device *pdev) @@ -556,13 +688,13 @@ static int dw8250_remove(struct platform_device *pdev) pm_runtime_get_sync(dev); - serial8250_unregister_port(data->data.line); + if (data->clk) { + clk_notifier_unregister(data->clk, &data->clk_notifier); - reset_control_assert(data->rst); - - clk_disable_unprepare(data->pclk); + flush_work(&data->clk_work); + } - clk_disable_unprepare(data->clk); + serial8250_unregister_port(data->data.line); pm_runtime_disable(dev); pm_runtime_put_noidle(dev); @@ -570,7 +702,6 @@ static int dw8250_remove(struct platform_device *pdev) return 0; } -#ifdef CONFIG_PM_SLEEP static int dw8250_suspend(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); @@ -588,9 +719,7 @@ static int dw8250_resume(struct device *dev) return 0; } -#endif /* CONFIG_PM_SLEEP */ -#ifdef CONFIG_PM static int dw8250_runtime_suspend(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); @@ -612,34 +741,60 @@ static int dw8250_runtime_resume(struct device *dev) return 0; } -#endif static const struct dev_pm_ops dw8250_pm_ops = { - SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume) - SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL) + SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume) + RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL) +}; + +static const struct dw8250_platform_data dw8250_dw_apb = { + .usr_reg = DW_UART_USR, +}; + +static const struct dw8250_platform_data dw8250_octeon_3860_data = { + .usr_reg = OCTEON_UART_USR, + .quirks = DW_UART_QUIRK_OCTEON, +}; + +static const struct dw8250_platform_data dw8250_armada_38x_data = { + .usr_reg = DW_UART_USR, + .quirks = DW_UART_QUIRK_ARMADA_38X, +}; + +static const struct dw8250_platform_data dw8250_renesas_rzn1_data = { + .usr_reg = DW_UART_USR, + .cpr_val = 0x00012f32, + .quirks = DW_UART_QUIRK_IS_DMA_FC, +}; + +static const struct dw8250_platform_data dw8250_starfive_jh7100_data = { + .usr_reg = DW_UART_USR, + .quirks = DW_UART_QUIRK_SKIP_SET_RATE, }; static const struct of_device_id dw8250_of_match[] = { - { .compatible = "snps,dw-apb-uart" }, - { .compatible = "cavium,octeon-3860-uart" }, - { .compatible = "marvell,armada-38x-uart" }, - { .compatible = "renesas,rzn1-uart" }, + { .compatible = "snps,dw-apb-uart", .data = &dw8250_dw_apb }, + { .compatible = "cavium,octeon-3860-uart", .data = &dw8250_octeon_3860_data }, + { .compatible = "marvell,armada-38x-uart", .data = &dw8250_armada_38x_data }, + { .compatible = "renesas,rzn1-uart", .data = &dw8250_renesas_rzn1_data }, + { .compatible = "starfive,jh7100-uart", .data = &dw8250_starfive_jh7100_data }, { /* Sentinel */ } }; MODULE_DEVICE_TABLE(of, dw8250_of_match); static const struct acpi_device_id dw8250_acpi_match[] = { - { "INT33C4", 0 }, - { "INT33C5", 0 }, - { "INT3434", 0 }, - { "INT3435", 0 }, - { "80860F0A", 0 }, - { "8086228A", 0 }, - { "APMC0D08", 0}, - { "AMD0020", 0 }, - { "AMDI0020", 0 }, - { "BRCM2032", 0 }, - { "HISI0031", 0 }, + { "80860F0A", (kernel_ulong_t)&dw8250_dw_apb }, + { "8086228A", (kernel_ulong_t)&dw8250_dw_apb }, + { "AMD0020", (kernel_ulong_t)&dw8250_dw_apb }, + { "AMDI0020", (kernel_ulong_t)&dw8250_dw_apb }, + { "AMDI0022", (kernel_ulong_t)&dw8250_dw_apb }, + { "APMC0D08", (kernel_ulong_t)&dw8250_dw_apb}, + { "BRCM2032", (kernel_ulong_t)&dw8250_dw_apb }, + { "HISI0031", (kernel_ulong_t)&dw8250_dw_apb }, + { "INT33C4", (kernel_ulong_t)&dw8250_dw_apb }, + { "INT33C5", (kernel_ulong_t)&dw8250_dw_apb }, + { "INT3434", (kernel_ulong_t)&dw8250_dw_apb }, + { "INT3435", (kernel_ulong_t)&dw8250_dw_apb }, { }, }; MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match); @@ -647,9 +802,9 @@ MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match); static struct platform_driver dw8250_platform_driver = { .driver = { .name = "dw-apb-uart", - .pm = &dw8250_pm_ops, + .pm = pm_ptr(&dw8250_pm_ops), .of_match_table = dw8250_of_match, - .acpi_match_table = ACPI_PTR(dw8250_acpi_match), + .acpi_match_table = dw8250_acpi_match, }, .probe = dw8250_probe, .remove = dw8250_remove, |