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

// SPDX-License-Identifier: GPL-2.0+
/*
 * Qualcomm UART driver
 *
 * (C) Copyright 2015 Mateusz Kulikowski <[email protected]>
 *
 * UART will work in Data Mover mode.
 * Based on Linux driver.
 */

#include <common.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
#include <serial.h>
#include <watchdog.h>
#include <asm/global_data.h>
#include <asm/io.h>
#include <linux/compiler.h>
#include <dm/pinctrl.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_MR1				 0x00
#define UARTDM_MR2				 0x04
#define UARTDM_CSR				 0xA0

#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 */

#define UART_DM_CLK_RX_TX_BIT_RATE 0xCC
#define MSM_BOOT_UART_DM_8_N_1_MODE 0x34
#define MSM_BOOT_UART_DM_CMD_RESET_RX 0x10
#define MSM_BOOT_UART_DM_CMD_RESET_TX 0x20

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 */
	uint32_t clk_bit_rate; /* data mover mode bit rate register value */
};

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 void uart_dm_init(struct msm_serial_data *priv)
{
	writel(priv->clk_bit_rate, priv->base + UARTDM_CSR);
	writel(0x0, priv->base + UARTDM_MR1);
	writel(MSM_BOOT_UART_DM_8_N_1_MODE, priv->base + UARTDM_MR2);
	writel(MSM_BOOT_UART_DM_CMD_RESET_RX, priv->base + UARTDM_CR);
	writel(MSM_BOOT_UART_DM_CMD_RESET_TX, priv->base + UARTDM_CR);
}
static int msm_serial_probe(struct udevice *dev)
{
	int ret;
	struct msm_serial_data *priv = dev_get_priv(dev);

	/* No need to reinitialize the UART after relocation */
	if (gd->flags & GD_FLG_RELOC)
		return 0;

	ret = msm_uart_clk_init(dev);
	if (ret)
		return ret;

	pinctrl_select_state(dev, "uart");
	uart_dm_init(priv);

	return 0;
}

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

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

	priv->clk_bit_rate = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), 
							"bit-rate", UART_DM_CLK_RX_TX_BIT_RATE);

	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,
	.of_to_plat = msm_serial_of_to_plat,
	.priv_auto	= sizeof(struct msm_serial_data),
	.probe = msm_serial_probe,
	.ops	= &msm_serial_ops,
};
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
142a20c3 MK	2	/*
	3	* Qualcomm UART driver
	4	*
	5	* (C) Copyright 2015 Mateusz Kulikowski <[email protected]>
	6	*
	7	* UART will work in Data Mover mode.
	8	* Based on Linux driver.
142a20c3 MK	9	*/
	10
	11	#include <common.h>
	12	#include <clk.h>
	13	#include <dm.h>
	14	#include <errno.h>
336d4615	15	#include <malloc.h>
142a20c3 MK	16	#include <serial.h>
142a20c3 MK	17	#include <watchdog.h>
401d1c4f	18	#include <asm/global_data.h>
142a20c3 MK	19	#include <asm/io.h>
142a20c3 MK	20	#include <linux/compiler.h>
b460b889	21	#include <dm/pinctrl.h>
142a20c3 MK	22
	23	/* Serial registers - this driver works in uartdm mode*/
	24
	25	#define UARTDM_DMRX 0x34 /* Max RX transfer length */
	26	#define UARTDM_NCF_TX 0x40 /* Number of chars to TX */
	27
	28	#define UARTDM_RXFS 0x50 /* RX channel status register */
	29	#define UARTDM_RXFS_BUF_SHIFT 0x7 /* Number of bytes in the packing buffer */
	30	#define UARTDM_RXFS_BUF_MASK 0x7
b460b889 RF	31	#define UARTDM_MR1 0x00
	32	#define UARTDM_MR2 0x04
	33	#define UARTDM_CSR 0xA0
142a20c3 MK	34
	35	#define UARTDM_SR 0xA4 /* Status register */
	36	#define UARTDM_SR_RX_READY (1 << 0) /* Word is the receiver FIFO */
	37	#define UARTDM_SR_TX_EMPTY (1 << 3) /* Transmitter underrun */
	38	#define UARTDM_SR_UART_OVERRUN (1 << 4) /* Receive overrun */
	39
	40	#define UARTDM_CR 0xA8 /* Command register */
	41	#define UARTDM_CR_CMD_RESET_ERR (3 << 4) /* Clear overrun error */
	42	#define UARTDM_CR_CMD_RESET_STALE_INT (8 << 4) /* Clears stale irq */
	43	#define UARTDM_CR_CMD_RESET_TX_READY (3 << 8) /* Clears TX Ready irq*/
	44	#define UARTDM_CR_CMD_FORCE_STALE (4 << 8) /* Causes stale event */
	45	#define UARTDM_CR_CMD_STALE_EVENT_DISABLE (6 << 8) /* Disable stale event */
	46
	47	#define UARTDM_IMR 0xB0 /* Interrupt mask register */
	48	#define UARTDM_ISR 0xB4 /* Interrupt status register */
	49	#define UARTDM_ISR_TX_READY 0x80 /* TX FIFO empty */
	50
	51	#define UARTDM_TF 0x100 /* UART Transmit FIFO register */
	52	#define UARTDM_RF 0x140 /* UART Receive FIFO register */
	53
b460b889 RF	54	#define UART_DM_CLK_RX_TX_BIT_RATE 0xCC
	55	#define MSM_BOOT_UART_DM_8_N_1_MODE 0x34
	56	#define MSM_BOOT_UART_DM_CMD_RESET_RX 0x10
	57	#define MSM_BOOT_UART_DM_CMD_RESET_TX 0x20
142a20c3 MK	58
	59	DECLARE_GLOBAL_DATA_PTR;
	60
	61	struct msm_serial_data {
	62	phys_addr_t base;
	63	unsigned chars_cnt; /* number of buffered chars */
	64	uint32_t chars_buf; /* buffered chars */
185dcf7f	65	uint32_t clk_bit_rate; /* data mover mode bit rate register value */
142a20c3 MK	66	};
	67
	68	static int msm_serial_fetch(struct udevice *dev)
	69	{
	70	struct msm_serial_data *priv = dev_get_priv(dev);
	71	unsigned sr;
	72
	73	if (priv->chars_cnt)
	74	return priv->chars_cnt;
	75
	76	/* Clear error in case of buffer overrun */
	77	if (readl(priv->base + UARTDM_SR) & UARTDM_SR_UART_OVERRUN)
	78	writel(UARTDM_CR_CMD_RESET_ERR, priv->base + UARTDM_CR);
	79
	80	/* We need to fetch new character */
	81	sr = readl(priv->base + UARTDM_SR);
	82
	83	if (sr & UARTDM_SR_RX_READY) {
	84	/* There are at least 4 bytes in fifo */
	85	priv->chars_buf = readl(priv->base + UARTDM_RF);
	86	priv->chars_cnt = 4;
	87	} else {
	88	/* Check if there is anything in fifo */
	89	priv->chars_cnt = readl(priv->base + UARTDM_RXFS);
	90	/* Extract number of characters in UART packing buffer*/
	91	priv->chars_cnt = (priv->chars_cnt >>
	92	UARTDM_RXFS_BUF_SHIFT) &
	93	UARTDM_RXFS_BUF_MASK;
	94	if (!priv->chars_cnt)
	95	return 0;
	96
	97	/* There is at least one charcter, move it to fifo */
	98	writel(UARTDM_CR_CMD_FORCE_STALE,
	99	priv->base + UARTDM_CR);
	100
	101	priv->chars_buf = readl(priv->base + UARTDM_RF);
	102	writel(UARTDM_CR_CMD_RESET_STALE_INT,
	103	priv->base + UARTDM_CR);
	104	writel(0x7, priv->base + UARTDM_DMRX);
	105	}
	106
	107	return priv->chars_cnt;
	108	}
	109
	110	static int msm_serial_getc(struct udevice *dev)
	111	{
	112	struct msm_serial_data *priv = dev_get_priv(dev);
	113	char c;
	114
	115	if (!msm_serial_fetch(dev))
	116	return -EAGAIN;
	117
	118	c = priv->chars_buf & 0xFF;
	119	priv->chars_buf >>= 8;
	120	priv->chars_cnt--;
	121
	122	return c;
	123	}
	124
	125	static int msm_serial_putc(struct udevice *dev, const char ch)
	126	{
	127	struct msm_serial_data *priv = dev_get_priv(dev);
	128
	129	if (!(readl(priv->base + UARTDM_SR) & UARTDM_SR_TX_EMPTY) &&
130	!(readl(priv->base + UARTDM_ISR) & UARTDM_ISR_TX_READY))
131	return -EAGAIN;
132
133	writel(UARTDM_CR_CMD_RESET_TX_READY, priv->base + UARTDM_CR);
134
135	writel(1, priv->base + UARTDM_NCF_TX);
136	writel(ch, priv->base + UARTDM_TF);
137
138	return 0;
139	}
140
141	static int msm_serial_pending(struct udevice *dev, bool input)
142	{
143	if (input) {
144	if (msm_serial_fetch(dev))
145	return 1;
146	}
147
148	return 0;
149	}
150
151	static const struct dm_serial_ops msm_serial_ops = {
152	.putc = msm_serial_putc,
153	.pending = msm_serial_pending,
154	.getc = msm_serial_getc,
155	};
156
157	static int msm_uart_clk_init(struct udevice *dev)
158	{
e160f7d4	159	uint clk_rate = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
142a20c3 MK	160	"clock-frequency", 115200);
	161	uint clkd[2]; /* clk_id and clk_no */
	162	int clk_offset;
135aa950 SW	163	struct udevice *clk_dev;
135aa950 SW	164	struct clk clk;
142a20c3 MK	165	int ret;
142a20c3 MK	166
e160f7d4 SG	167	ret = fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev), "clock",
e160f7d4 SG	168	clkd, 2);
142a20c3 MK	169	if (ret)
	170	return ret;
	171
	172	clk_offset = fdt_node_offset_by_phandle(gd->fdt_blob, clkd[0]);
	173	if (clk_offset < 0)
	174	return clk_offset;
	175
135aa950	176	ret = uclass_get_device_by_of_offset(UCLASS_CLK, clk_offset, &clk_dev);
142a20c3 MK	177	if (ret)
	178	return ret;
	179
135aa950 SW	180	clk.id = clkd[1];
	181	ret = clk_request(clk_dev, &clk);
	182	if (ret < 0)
	183	return ret;
	184
	185	ret = clk_set_rate(&clk, clk_rate);
	186	clk_free(&clk);
142a20c3 MK	187	if (ret < 0)
	188	return ret;
	189
	190	return 0;
	191	}
	192
b460b889 RF	193	static void uart_dm_init(struct msm_serial_data *priv)
b460b889 RF	194	{
185dcf7f	195	writel(priv->clk_bit_rate, priv->base + UARTDM_CSR);
b460b889 RF	196	writel(0x0, priv->base + UARTDM_MR1);
	197	writel(MSM_BOOT_UART_DM_8_N_1_MODE, priv->base + UARTDM_MR2);
	198	writel(MSM_BOOT_UART_DM_CMD_RESET_RX, priv->base + UARTDM_CR);
	199	writel(MSM_BOOT_UART_DM_CMD_RESET_TX, priv->base + UARTDM_CR);
	200	}
142a20c3 MK	201	static int msm_serial_probe(struct udevice *dev)
142a20c3 MK	202	{
11d59fe5	203	int ret;
142a20c3 MK	204	struct msm_serial_data *priv = dev_get_priv(dev);
142a20c3 MK	205
7e5ad796 RF	206	/* No need to reinitialize the UART after relocation */
	207	if (gd->flags & GD_FLG_RELOC)
	208	return 0;
	209
11d59fe5 RF	210	ret = msm_uart_clk_init(dev);
	211	if (ret)
	212	return ret;
142a20c3	213
b460b889 RF	214	pinctrl_select_state(dev, "uart");
b460b889 RF	215	uart_dm_init(priv);
142a20c3 MK	216
	217	return 0;
	218	}
	219
d1998a9f	220	static int msm_serial_of_to_plat(struct udevice *dev)
142a20c3 MK	221	{
	222	struct msm_serial_data *priv = dev_get_priv(dev);
	223
2548493a	224	priv->base = dev_read_addr(dev);
142a20c3 MK	225	if (priv->base == FDT_ADDR_T_NONE)
	226	return -EINVAL;
	227
185dcf7f RM	228	priv->clk_bit_rate = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
	229	"bit-rate", UART_DM_CLK_RX_TX_BIT_RATE);
	230
142a20c3 MK	231	return 0;
	232	}
	233
	234	static const struct udevice_id msm_serial_ids[] = {
	235	{ .compatible = "qcom,msm-uartdm-v1.4" },
	236	{ }
	237	};
	238
	239	U_BOOT_DRIVER(serial_msm) = {
	240	.name = "serial_msm",
	241	.id = UCLASS_SERIAL,
	242	.of_match = msm_serial_ids,
d1998a9f	243	.of_to_plat = msm_serial_of_to_plat,
41575d8e	244	.priv_auto = sizeof(struct msm_serial_data),
142a20c3 MK	245	.probe = msm_serial_probe,
	246	.ops = &msm_serial_ops,
	247	};