[J-u-boot.git] / drivers / serial / serial_bcm283x_mu.c

/*
 * (C) Copyright 2016 Stephen Warren <[email protected]>
 *
 * Derived from pl01x code:
 *
 * (C) Copyright 2000
 * Rob Taylor, Flying Pig Systems. [email protected].
 *
 * (C) Copyright 2004
 * ARM Ltd.
 * Philippe Robin, <[email protected]>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/* Simple U-Boot driver for the BCM283x mini UART */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include <asm/io.h>
#include <serial.h>
#include <dm/platform_data/serial_bcm283x_mu.h>
#include <linux/compiler.h>
#include <fdtdec.h>

DECLARE_GLOBAL_DATA_PTR;

struct bcm283x_mu_regs {
	u32 io;
	u32 iir;
	u32 ier;
	u32 lcr;
	u32 mcr;
	u32 lsr;
	u32 msr;
	u32 scratch;
	u32 cntl;
	u32 stat;
	u32 baud;
};

#define BCM283X_MU_LCR_DATA_SIZE_8	3

#define BCM283X_MU_LSR_TX_IDLE		BIT(6)
/* This actually means not full, but is named not empty in the docs */
#define BCM283X_MU_LSR_TX_EMPTY		BIT(5)
#define BCM283X_MU_LSR_RX_READY		BIT(0)

struct bcm283x_mu_priv {
	struct bcm283x_mu_regs *regs;
};

static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate)
{
	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	struct bcm283x_mu_regs *regs = priv->regs;
	u32 divider;

	if (plat->disabled || plat->skip_init)
		return 0;

	divider = plat->clock / (baudrate * 8);

	writel(BCM283X_MU_LCR_DATA_SIZE_8, &regs->lcr);
	writel(divider - 1, &regs->baud);

	return 0;
}

static int bcm283x_mu_serial_probe(struct udevice *dev)
{
	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	struct bcm283x_mu_priv *priv = dev_get_priv(dev);

	if (plat->disabled)
		return -ENODEV;

	priv->regs = (struct bcm283x_mu_regs *)plat->base;

	return 0;
}

static int bcm283x_mu_serial_getc(struct udevice *dev)
{
	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	struct bcm283x_mu_regs *regs = priv->regs;
	u32 data;

	if (plat->disabled)
		return -EAGAIN;

	/* Wait until there is data in the FIFO */
	if (!(readl(&regs->lsr) & BCM283X_MU_LSR_RX_READY))
		return -EAGAIN;

	data = readl(&regs->io);

	return (int)data;
}

static int bcm283x_mu_serial_putc(struct udevice *dev, const char data)
{
	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	struct bcm283x_mu_regs *regs = priv->regs;

	if (plat->disabled)
		return 0;

	/* Wait until there is space in the FIFO */
	if (!(readl(&regs->lsr) & BCM283X_MU_LSR_TX_EMPTY))
		return -EAGAIN;

	/* Send the character */
	writel(data, &regs->io);

	return 0;
}

static int bcm283x_mu_serial_pending(struct udevice *dev, bool input)
{
	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	struct bcm283x_mu_regs *regs = priv->regs;
	unsigned int lsr;

	if (plat->disabled)
		return 0;

	lsr = readl(&regs->lsr);

	if (input) {
		WATCHDOG_RESET();
		return (lsr & BCM283X_MU_LSR_RX_READY) ? 1 : 0;
	} else {
		return (lsr & BCM283X_MU_LSR_TX_IDLE) ? 0 : 1;
	}
}

static const struct dm_serial_ops bcm283x_mu_serial_ops = {
	.putc = bcm283x_mu_serial_putc,
	.pending = bcm283x_mu_serial_pending,
	.getc = bcm283x_mu_serial_getc,
	.setbrg = bcm283x_mu_serial_setbrg,
};

#if CONFIG_IS_ENABLED(OF_CONTROL)
static const struct udevice_id bcm283x_mu_serial_id[] = {
	{.compatible = "brcm,bcm2835-aux-uart"},
	{}
};

static int bcm283x_mu_serial_ofdata_to_platdata(struct udevice *dev)
{
	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	fdt_addr_t addr;

	addr = dev_get_addr(dev);
	if (addr == FDT_ADDR_T_NONE)
		return -EINVAL;

	plat->base = addr;
	plat->clock = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "clock", 1);
	plat->skip_init = fdtdec_get_bool(gd->fdt_blob, dev->of_offset,
	                                  "skip-init");
	plat->disabled = false;
	return 0;
}
#endif

U_BOOT_DRIVER(serial_bcm283x_mu) = {
	.name = "serial_bcm283x_mu",
	.id = UCLASS_SERIAL,
	.of_match = of_match_ptr(bcm283x_mu_serial_id),
	.ofdata_to_platdata = of_match_ptr(bcm283x_mu_serial_ofdata_to_platdata),
	.platdata_auto_alloc_size = sizeof(struct bcm283x_mu_serial_platdata),
	.probe = bcm283x_mu_serial_probe,
	.ops = &bcm283x_mu_serial_ops,
	.flags = DM_FLAG_PRE_RELOC,
	.priv_auto_alloc_size = sizeof(struct bcm283x_mu_priv),
};
Commit	Line	Data
3917c269 SW	1	/*
	2	* (C) Copyright 2016 Stephen Warren <[email protected]>
	3	*
	4	* Derived from pl01x code:
	5	*
	6	* (C) Copyright 2000
	7	* Rob Taylor, Flying Pig Systems. [email protected].
	8	*
	9	* (C) Copyright 2004
	10	* ARM Ltd.
	11	* Philippe Robin, <[email protected]>
	12	*
	13	* SPDX-License-Identifier: GPL-2.0+
	14	*/
	15
	16	/* Simple U-Boot driver for the BCM283x mini UART */
	17
	18	#include <common.h>
	19	#include <dm.h>
	20	#include <errno.h>
	21	#include <watchdog.h>
	22	#include <asm/io.h>
	23	#include <serial.h>
	24	#include <dm/platform_data/serial_bcm283x_mu.h>
	25	#include <linux/compiler.h>
	26	#include <fdtdec.h>
	27
9f755f5d FV	28	DECLARE_GLOBAL_DATA_PTR;
9f755f5d FV	29
3917c269 SW	30	struct bcm283x_mu_regs {
	31	u32 io;
	32	u32 iir;
	33	u32 ier;
	34	u32 lcr;
	35	u32 mcr;
	36	u32 lsr;
	37	u32 msr;
	38	u32 scratch;
	39	u32 cntl;
	40	u32 stat;
	41	u32 baud;
	42	};
	43
	44	#define BCM283X_MU_LCR_DATA_SIZE_8 3
	45
	46	#define BCM283X_MU_LSR_TX_IDLE BIT(6)
	47	/* This actually means not full, but is named not empty in the docs */
	48	#define BCM283X_MU_LSR_TX_EMPTY BIT(5)
	49	#define BCM283X_MU_LSR_RX_READY BIT(0)
	50
	51	struct bcm283x_mu_priv {
	52	struct bcm283x_mu_regs *regs;
	53	};
	54
	55	static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate)
	56	{
	57	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	58	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	59	struct bcm283x_mu_regs *regs = priv->regs;
	60	u32 divider;
	61
cb97ad47	62	if (plat->disabled \|\| plat->skip_init)
3917c269 SW	63	return 0;
	64
	65	divider = plat->clock / (baudrate * 8);
	66
	67	writel(BCM283X_MU_LCR_DATA_SIZE_8, &regs->lcr);
	68	writel(divider - 1, &regs->baud);
	69
	70	return 0;
	71	}
	72
	73	static int bcm283x_mu_serial_probe(struct udevice *dev)
	74	{
	75	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	76	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	77
601147b0 AG	78	if (plat->disabled)
	79	return -ENODEV;
	80
3917c269 SW	81	priv->regs = (struct bcm283x_mu_regs *)plat->base;
	82
	83	return 0;
	84	}
	85
	86	static int bcm283x_mu_serial_getc(struct udevice *dev)
	87	{
cb97ad47	88	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
3917c269 SW	89	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	90	struct bcm283x_mu_regs *regs = priv->regs;
	91	u32 data;
	92
cb97ad47 FV	93	if (plat->disabled)
	94	return -EAGAIN;
	95
3917c269 SW	96	/* Wait until there is data in the FIFO */
	97	if (!(readl(&regs->lsr) & BCM283X_MU_LSR_RX_READY))
	98	return -EAGAIN;
	99
	100	data = readl(&regs->io);
	101
	102	return (int)data;
	103	}
	104
	105	static int bcm283x_mu_serial_putc(struct udevice *dev, const char data)
	106	{
cb97ad47	107	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
3917c269 SW	108	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
	109	struct bcm283x_mu_regs *regs = priv->regs;
	110
cb97ad47 FV	111	if (plat->disabled)
	112	return 0;
	113
3917c269 SW	114	/* Wait until there is space in the FIFO */
	115	if (!(readl(&regs->lsr) & BCM283X_MU_LSR_TX_EMPTY))
	116	return -EAGAIN;
	117
	118	/* Send the character */
	119	writel(data, &regs->io);
	120
	121	return 0;
	122	}
	123
	124	static int bcm283x_mu_serial_pending(struct udevice *dev, bool input)
	125	{
cb97ad47	126	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
3917c269 SW	127	struct bcm283x_mu_priv *priv = dev_get_priv(dev);
3917c269 SW	128	struct bcm283x_mu_regs *regs = priv->regs;
cb97ad47 FV	129	unsigned int lsr;
	130
	131	if (plat->disabled)
	132	return 0;
	133
	134	lsr = readl(&regs->lsr);
3917c269 SW	135
	136	if (input) {
	137	WATCHDOG_RESET();
e3a46e3e	138	return (lsr & BCM283X_MU_LSR_RX_READY) ? 1 : 0;
3917c269	139	} else {
e3a46e3e	140	return (lsr & BCM283X_MU_LSR_TX_IDLE) ? 0 : 1;
3917c269 SW	141	}
	142	}
	143
	144	static const struct dm_serial_ops bcm283x_mu_serial_ops = {
	145	.putc = bcm283x_mu_serial_putc,
	146	.pending = bcm283x_mu_serial_pending,
	147	.getc = bcm283x_mu_serial_getc,
	148	.setbrg = bcm283x_mu_serial_setbrg,
	149	};
	150
9f755f5d FV	151	#if CONFIG_IS_ENABLED(OF_CONTROL)
	152	static const struct udevice_id bcm283x_mu_serial_id[] = {
	153	{.compatible = "brcm,bcm2835-aux-uart"},
	154	{}
	155	};
	156
	157	static int bcm283x_mu_serial_ofdata_to_platdata(struct udevice *dev)
	158	{
	159	struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev);
	160	fdt_addr_t addr;
	161
	162	addr = dev_get_addr(dev);
	163	if (addr == FDT_ADDR_T_NONE)
	164	return -EINVAL;
	165
	166	plat->base = addr;
	167	plat->clock = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "clock", 1);
	168	plat->skip_init = fdtdec_get_bool(gd->fdt_blob, dev->of_offset,
	169	"skip-init");
	170	plat->disabled = false;
	171	return 0;
	172	}
	173	#endif
	174
3917c269 SW	175	U_BOOT_DRIVER(serial_bcm283x_mu) = {
	176	.name = "serial_bcm283x_mu",
	177	.id = UCLASS_SERIAL,
9f755f5d FV	178	.of_match = of_match_ptr(bcm283x_mu_serial_id),
9f755f5d FV	179	.ofdata_to_platdata = of_match_ptr(bcm283x_mu_serial_ofdata_to_platdata),
3917c269 SW	180	.platdata_auto_alloc_size = sizeof(struct bcm283x_mu_serial_platdata),
	181	.probe = bcm283x_mu_serial_probe,
	182	.ops = &bcm283x_mu_serial_ops,
	183	.flags = DM_FLAG_PRE_RELOC,
	184	.priv_auto_alloc_size = sizeof(struct bcm283x_mu_priv),
	185	};