[people/ms/u-boot.git] / drivers / serial / serial_msm.c

/*
 * Qualcomm UART driver
 *
 * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
 *
 * UART will work in Data Mover mode.
 * Based on Linux driver.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

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

/* Serial registers - this driver works in uartdm mode*/

#define UARTDM_DMRX             0x34 /* Max RX transfer length */
#define UARTDM_NCF_TX           0x40 /* Number of chars to TX */

#define UARTDM_RXFS             0x50 /* RX channel status register */
#define UARTDM_RXFS_BUF_SHIFT   0x7  /* Number of bytes in the packing buffer */
#define UARTDM_RXFS_BUF_MASK    0x7

#define UARTDM_SR                0xA4 /* Status register */
#define UARTDM_SR_RX_READY       (1 << 0) /* Word is the receiver FIFO */
#define UARTDM_SR_TX_EMPTY       (1 << 3) /* Transmitter underrun */
#define UARTDM_SR_UART_OVERRUN   (1 << 4) /* Receive overrun */

#define UARTDM_CR                         0xA8 /* Command register */
#define UARTDM_CR_CMD_RESET_ERR           (3 << 4) /* Clear overrun error */
#define UARTDM_CR_CMD_RESET_STALE_INT     (8 << 4) /* Clears stale irq */
#define UARTDM_CR_CMD_RESET_TX_READY      (3 << 8) /* Clears TX Ready irq*/
#define UARTDM_CR_CMD_FORCE_STALE         (4 << 8) /* Causes stale event */
#define UARTDM_CR_CMD_STALE_EVENT_DISABLE (6 << 8) /* Disable stale event */

#define UARTDM_IMR                0xB0 /* Interrupt mask register */
#define UARTDM_ISR                0xB4 /* Interrupt status register */
#define UARTDM_ISR_TX_READY       0x80 /* TX FIFO empty */

#define UARTDM_TF               0x100 /* UART Transmit FIFO register */
#define UARTDM_RF               0x140 /* UART Receive FIFO register */


DECLARE_GLOBAL_DATA_PTR;

struct msm_serial_data {
	phys_addr_t base;
	unsigned chars_cnt; /* number of buffered chars */
	uint32_t chars_buf; /* buffered chars */
};

static int msm_serial_fetch(struct udevice *dev)
{
	struct msm_serial_data *priv = dev_get_priv(dev);
	unsigned sr;

	if (priv->chars_cnt)
		return priv->chars_cnt;

	/* Clear error in case of buffer overrun */
	if (readl(priv->base + UARTDM_SR) & UARTDM_SR_UART_OVERRUN)
		writel(UARTDM_CR_CMD_RESET_ERR, priv->base + UARTDM_CR);

	/* We need to fetch new character */
	sr = readl(priv->base + UARTDM_SR);

	if (sr & UARTDM_SR_RX_READY) {
		/* There are at least 4 bytes in fifo */
		priv->chars_buf = readl(priv->base + UARTDM_RF);
		priv->chars_cnt = 4;
	} else {
		/* Check if there is anything in fifo */
		priv->chars_cnt = readl(priv->base + UARTDM_RXFS);
		/* Extract number of characters in UART packing buffer*/
		priv->chars_cnt = (priv->chars_cnt >>
				   UARTDM_RXFS_BUF_SHIFT) &
				  UARTDM_RXFS_BUF_MASK;
		if (!priv->chars_cnt)
			return 0;

		/* There is at least one charcter, move it to fifo */
		writel(UARTDM_CR_CMD_FORCE_STALE,
		       priv->base + UARTDM_CR);

		priv->chars_buf = readl(priv->base + UARTDM_RF);
		writel(UARTDM_CR_CMD_RESET_STALE_INT,
		       priv->base + UARTDM_CR);
		writel(0x7, priv->base + UARTDM_DMRX);
	}

	return priv->chars_cnt;
}

static int msm_serial_getc(struct udevice *dev)
{
	struct msm_serial_data *priv = dev_get_priv(dev);
	char c;

	if (!msm_serial_fetch(dev))
		return -EAGAIN;

	c = priv->chars_buf & 0xFF;
	priv->chars_buf >>= 8;
	priv->chars_cnt--;

	return c;
}

static int msm_serial_putc(struct udevice *dev, const char ch)
{
	struct msm_serial_data *priv = dev_get_priv(dev);

	if (!(readl(priv->base + UARTDM_SR) & UARTDM_SR_TX_EMPTY) &&
	    !(readl(priv->base + UARTDM_ISR) & UARTDM_ISR_TX_READY))
		return -EAGAIN;

	writel(UARTDM_CR_CMD_RESET_TX_READY, priv->base + UARTDM_CR);

	writel(1, priv->base + UARTDM_NCF_TX);
	writel(ch, priv->base + UARTDM_TF);

	return 0;
}

static int msm_serial_pending(struct udevice *dev, bool input)
{
	if (input) {
		if (msm_serial_fetch(dev))
			return 1;
	}

	return 0;
}

static const struct dm_serial_ops msm_serial_ops = {
	.putc = msm_serial_putc,
	.pending = msm_serial_pending,
	.getc = msm_serial_getc,
};

static int msm_uart_clk_init(struct udevice *dev)
{
	uint clk_rate = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
					"clock-frequency", 115200);
	uint clkd[2]; /* clk_id and clk_no */
	int clk_offset;
	struct udevice *clk_dev;
	struct clk clk;
	int ret;

	ret = fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev), "clock",
				   clkd, 2);
	if (ret)
		return ret;

	clk_offset = fdt_node_offset_by_phandle(gd->fdt_blob, clkd[0]);
	if (clk_offset < 0)
		return clk_offset;

	ret = uclass_get_device_by_of_offset(UCLASS_CLK, clk_offset, &clk_dev);
	if (ret)
		return ret;

	clk.id = clkd[1];
	ret = clk_request(clk_dev, &clk);
	if (ret < 0)
		return ret;

	ret = clk_set_rate(&clk, clk_rate);
	clk_free(&clk);
	if (ret < 0)
		return ret;

	return 0;
}

static int msm_serial_probe(struct udevice *dev)
{
	struct msm_serial_data *priv = dev_get_priv(dev);

	msm_uart_clk_init(dev); /* Ignore return value and hope clock was
				  properly initialized by earlier loaders */

	if (readl(priv->base + UARTDM_SR) & UARTDM_SR_UART_OVERRUN)
		writel(UARTDM_CR_CMD_RESET_ERR, priv->base + UARTDM_CR);

	writel(0, priv->base + UARTDM_IMR);
	writel(UARTDM_CR_CMD_STALE_EVENT_DISABLE, priv->base + UARTDM_CR);
	msm_serial_fetch(dev);

	return 0;
}

static int msm_serial_ofdata_to_platdata(struct udevice *dev)
{
	struct msm_serial_data *priv = dev_get_priv(dev);

	priv->base = devfdt_get_addr(dev);
	if (priv->base == FDT_ADDR_T_NONE)
		return -EINVAL;

	return 0;
}

static const struct udevice_id msm_serial_ids[] = {
	{ .compatible = "qcom,msm-uartdm-v1.4" },
	{ }
};

U_BOOT_DRIVER(serial_msm) = {
	.name	= "serial_msm",
	.id	= UCLASS_SERIAL,
	.of_match = msm_serial_ids,
	.ofdata_to_platdata = msm_serial_ofdata_to_platdata,
	.priv_auto_alloc_size = sizeof(struct msm_serial_data),
	.probe = msm_serial_probe,
	.ops	= &msm_serial_ops,
};
Commit	Line	Data
142a20c3 MK	1	/*
	2	* Qualcomm UART driver
	3	*
	4	* (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
	5	*
	6	* UART will work in Data Mover mode.
	7	* Based on Linux driver.
	8	*
	9	* SPDX-License-Identifier: GPL-2.0+
	10	*/
	11
	12	#include <common.h>
	13	#include <clk.h>
	14	#include <dm.h>
	15	#include <errno.h>
	16	#include <serial.h>
	17	#include <watchdog.h>
	18	#include <asm/io.h>
	19	#include <linux/compiler.h>
	20
	21	/* Serial registers - this driver works in uartdm mode*/
	22
	23	#define UARTDM_DMRX 0x34 /* Max RX transfer length */
	24	#define UARTDM_NCF_TX 0x40 /* Number of chars to TX */
	25
	26	#define UARTDM_RXFS 0x50 /* RX channel status register */
	27	#define UARTDM_RXFS_BUF_SHIFT 0x7 /* Number of bytes in the packing buffer */
	28	#define UARTDM_RXFS_BUF_MASK 0x7
	29
	30	#define UARTDM_SR 0xA4 /* Status register */
	31	#define UARTDM_SR_RX_READY (1 << 0) /* Word is the receiver FIFO */
	32	#define UARTDM_SR_TX_EMPTY (1 << 3) /* Transmitter underrun */
	33	#define UARTDM_SR_UART_OVERRUN (1 << 4) /* Receive overrun */
	34
	35	#define UARTDM_CR 0xA8 /* Command register */
	36	#define UARTDM_CR_CMD_RESET_ERR (3 << 4) /* Clear overrun error */
	37	#define UARTDM_CR_CMD_RESET_STALE_INT (8 << 4) /* Clears stale irq */
	38	#define UARTDM_CR_CMD_RESET_TX_READY (3 << 8) /* Clears TX Ready irq*/
	39	#define UARTDM_CR_CMD_FORCE_STALE (4 << 8) /* Causes stale event */
	40	#define UARTDM_CR_CMD_STALE_EVENT_DISABLE (6 << 8) /* Disable stale event */
	41
	42	#define UARTDM_IMR 0xB0 /* Interrupt mask register */
	43	#define UARTDM_ISR 0xB4 /* Interrupt status register */
	44	#define UARTDM_ISR_TX_READY 0x80 /* TX FIFO empty */
	45
	46	#define UARTDM_TF 0x100 /* UART Transmit FIFO register */
	47	#define UARTDM_RF 0x140 /* UART Receive FIFO register */
	48
	49
	50	DECLARE_GLOBAL_DATA_PTR;
	51
	52	struct msm_serial_data {
	53	phys_addr_t base;
	54	unsigned chars_cnt; /* number of buffered chars */
	55	uint32_t chars_buf; /* buffered chars */
	56	};
	57
	58	static int msm_serial_fetch(struct udevice *dev)
	59	{
	60	struct msm_serial_data *priv = dev_get_priv(dev);
	61	unsigned sr;
	62
	63	if (priv->chars_cnt)
	64	return priv->chars_cnt;
65
66	/* Clear error in case of buffer overrun */
67	if (readl(priv->base + UARTDM_SR) & UARTDM_SR_UART_OVERRUN)
68	writel(UARTDM_CR_CMD_RESET_ERR, priv->base + UARTDM_CR);
69
70	/* We need to fetch new character */
71	sr = readl(priv->base + UARTDM_SR);
72
73	if (sr & UARTDM_SR_RX_READY) {
74	/* There are at least 4 bytes in fifo */
75	priv->chars_buf = readl(priv->base + UARTDM_RF);
76	priv->chars_cnt = 4;
77	} else {
78	/* Check if there is anything in fifo */
79	priv->chars_cnt = readl(priv->base + UARTDM_RXFS);
80	/* Extract number of characters in UART packing buffer*/
81	priv->chars_cnt = (priv->chars_cnt >>
82	UARTDM_RXFS_BUF_SHIFT) &
83	UARTDM_RXFS_BUF_MASK;
84	if (!priv->chars_cnt)
85	return 0;
86
87	/* There is at least one charcter, move it to fifo */
88	writel(UARTDM_CR_CMD_FORCE_STALE,
89	priv->base + UARTDM_CR);
90
91	priv->chars_buf = readl(priv->base + UARTDM_RF);
92	writel(UARTDM_CR_CMD_RESET_STALE_INT,
93	priv->base + UARTDM_CR);
94	writel(0x7, priv->base + UARTDM_DMRX);
95	}
96
97	return priv->chars_cnt;
98	}
99
100	static int msm_serial_getc(struct udevice *dev)
101	{
102	struct msm_serial_data *priv = dev_get_priv(dev);
103	char c;
104
105	if (!msm_serial_fetch(dev))
106	return -EAGAIN;
107
108	c = priv->chars_buf & 0xFF;
109	priv->chars_buf >>= 8;
110	priv->chars_cnt--;
111
112	return c;
113	}
114
115	static int msm_serial_putc(struct udevice *dev, const char ch)
116	{
117	struct msm_serial_data *priv = dev_get_priv(dev);
118
119	if (!(readl(priv->base + UARTDM_SR) & UARTDM_SR_TX_EMPTY) &&
120	!(readl(priv->base + UARTDM_ISR) & UARTDM_ISR_TX_READY))
121	return -EAGAIN;
122
123	writel(UARTDM_CR_CMD_RESET_TX_READY, priv->base + UARTDM_CR);
124
125	writel(1, priv->base + UARTDM_NCF_TX);
126	writel(ch, priv->base + UARTDM_TF);
127
128	return 0;
129	}
130
131	static int msm_serial_pending(struct udevice *dev, bool input)
132	{
133	if (input) {
134	if (msm_serial_fetch(dev))
135	return 1;
136	}
137
138	return 0;
139	}
140
141	static const struct dm_serial_ops msm_serial_ops = {
142	.putc = msm_serial_putc,
143	.pending = msm_serial_pending,
144	.getc = msm_serial_getc,
145	};
146
147	static int msm_uart_clk_init(struct udevice *dev)
148	{
e160f7d4	149	uint clk_rate = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
142a20c3 MK	150	"clock-frequency", 115200);
	151	uint clkd[2]; /* clk_id and clk_no */
	152	int clk_offset;
135aa950 SW	153	struct udevice *clk_dev;
135aa950 SW	154	struct clk clk;
142a20c3 MK	155	int ret;
142a20c3 MK	156
e160f7d4 SG	157	ret = fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev), "clock",
e160f7d4 SG	158	clkd, 2);
142a20c3 MK	159	if (ret)
	160	return ret;
	161
	162	clk_offset = fdt_node_offset_by_phandle(gd->fdt_blob, clkd[0]);
	163	if (clk_offset < 0)
	164	return clk_offset;
	165
135aa950	166	ret = uclass_get_device_by_of_offset(UCLASS_CLK, clk_offset, &clk_dev);
142a20c3 MK	167	if (ret)
	168	return ret;
	169
135aa950 SW	170	clk.id = clkd[1];
	171	ret = clk_request(clk_dev, &clk);
	172	if (ret < 0)
	173	return ret;
	174
	175	ret = clk_set_rate(&clk, clk_rate);
	176	clk_free(&clk);
142a20c3 MK	177	if (ret < 0)
	178	return ret;
	179
	180	return 0;
	181	}
	182
	183	static int msm_serial_probe(struct udevice *dev)
	184	{
	185	struct msm_serial_data *priv = dev_get_priv(dev);
	186
	187	msm_uart_clk_init(dev); /* Ignore return value and hope clock was
	188	properly initialized by earlier loaders */
	189
	190	if (readl(priv->base + UARTDM_SR) & UARTDM_SR_UART_OVERRUN)
	191	writel(UARTDM_CR_CMD_RESET_ERR, priv->base + UARTDM_CR);
	192
	193	writel(0, priv->base + UARTDM_IMR);
	194	writel(UARTDM_CR_CMD_STALE_EVENT_DISABLE, priv->base + UARTDM_CR);
	195	msm_serial_fetch(dev);
	196
	197	return 0;
	198	}
	199
	200	static int msm_serial_ofdata_to_platdata(struct udevice *dev)
	201	{
	202	struct msm_serial_data *priv = dev_get_priv(dev);
	203
a821c4af	204	priv->base = devfdt_get_addr(dev);
142a20c3 MK	205	if (priv->base == FDT_ADDR_T_NONE)
	206	return -EINVAL;
	207
	208	return 0;
	209	}
	210
	211	static const struct udevice_id msm_serial_ids[] = {
	212	{ .compatible = "qcom,msm-uartdm-v1.4" },
	213	{ }
	214	};
	215
	216	U_BOOT_DRIVER(serial_msm) = {
	217	.name = "serial_msm",
	218	.id = UCLASS_SERIAL,
	219	.of_match = msm_serial_ids,
	220	.ofdata_to_platdata = msm_serial_ofdata_to_platdata,
	221	.priv_auto_alloc_size = sizeof(struct msm_serial_data),
	222	.probe = msm_serial_probe,
	223	.ops = &msm_serial_ops,
	224	};