1 // SPDX-License-Identifier: GPL-2.0+
3 * Qualcomm GENI serial engine UART driver
7 * Based on Linux driver.
14 #include <linux/delay.h>
15 #include <linux/time.h>
19 #define UART_OVERSAMPLING 32
20 #define STALE_TIMEOUT 160
23 #define GENI_FORCE_DEFAULT_REG 0x20
24 #define GENI_SER_M_CLK_CFG 0x48
25 #define GENI_SER_S_CLK_CFG 0x4C
26 #define SE_HW_PARAM_0 0xE24
27 #define SE_GENI_STATUS 0x40
28 #define SE_GENI_S_CMD0 0x630
29 #define SE_GENI_S_CMD_CTRL_REG 0x634
30 #define SE_GENI_S_IRQ_CLEAR 0x648
31 #define SE_GENI_S_IRQ_STATUS 0x640
32 #define SE_GENI_S_IRQ_EN 0x644
33 #define SE_GENI_M_CMD0 0x600
34 #define SE_GENI_M_CMD_CTRL_REG 0x604
35 #define SE_GENI_M_IRQ_CLEAR 0x618
36 #define SE_GENI_M_IRQ_STATUS 0x610
37 #define SE_GENI_M_IRQ_EN 0x614
38 #define SE_GENI_TX_FIFOn 0x700
39 #define SE_GENI_RX_FIFOn 0x780
40 #define SE_GENI_TX_FIFO_STATUS 0x800
41 #define SE_GENI_RX_FIFO_STATUS 0x804
42 #define SE_GENI_TX_WATERMARK_REG 0x80C
43 #define SE_GENI_TX_PACKING_CFG0 0x260
44 #define SE_GENI_TX_PACKING_CFG1 0x264
45 #define SE_GENI_RX_PACKING_CFG0 0x284
46 #define SE_GENI_RX_PACKING_CFG1 0x288
47 #define SE_UART_RX_STALE_CNT 0x294
48 #define SE_UART_TX_TRANS_LEN 0x270
49 #define SE_UART_TX_STOP_BIT_LEN 0x26c
50 #define SE_UART_TX_WORD_LEN 0x268
51 #define SE_UART_RX_WORD_LEN 0x28c
52 #define SE_UART_TX_TRANS_CFG 0x25c
53 #define SE_UART_TX_PARITY_CFG 0x2a4
54 #define SE_UART_RX_TRANS_CFG 0x280
55 #define SE_UART_RX_PARITY_CFG 0x2a8
57 #define M_TX_FIFO_WATERMARK_EN (BIT(30))
59 /* GENI_FORCE_DEFAULT_REG fields */
60 #define FORCE_DEFAULT (BIT(0))
62 #define S_CMD_ABORT_EN (BIT(5))
64 #define UART_START_READ 0x1
66 /* GENI_M_CMD_CTRL_REG */
67 #define M_GENI_CMD_CANCEL (BIT(2))
68 #define M_GENI_CMD_ABORT (BIT(1))
69 #define M_GENI_DISABLE (BIT(0))
71 #define M_CMD_ABORT_EN (BIT(5))
72 #define M_CMD_DONE_EN (BIT(0))
73 #define M_CMD_DONE_DISABLE_MASK (~M_CMD_DONE_EN)
75 #define S_GENI_CMD_ABORT (BIT(1))
77 /* GENI_S_CMD0 fields */
78 #define S_OPCODE_MSK (GENMASK(31, 27))
79 #define S_PARAMS_MSK (GENMASK(26, 0))
81 /* GENI_STATUS fields */
82 #define M_GENI_CMD_ACTIVE (BIT(0))
83 #define S_GENI_CMD_ACTIVE (BIT(12))
84 #define M_CMD_DONE_EN (BIT(0))
85 #define S_CMD_DONE_EN (BIT(0))
87 #define M_OPCODE_SHIFT 27
88 #define S_OPCODE_SHIFT 27
89 #define M_TX_FIFO_WATERMARK_EN (BIT(30))
90 #define UART_START_TX 0x1
91 #define UART_CTS_MASK (BIT(1))
92 #define M_SEC_IRQ_EN (BIT(31))
93 #define TX_FIFO_WC_MSK (GENMASK(27, 0))
94 #define RX_FIFO_WC_MSK (GENMASK(24, 0))
96 #define S_RX_FIFO_WATERMARK_EN (BIT(26))
97 #define S_RX_FIFO_LAST_EN (BIT(27))
98 #define M_RX_FIFO_WATERMARK_EN (BIT(26))
99 #define M_RX_FIFO_LAST_EN (BIT(27))
101 /* GENI_SER_M_CLK_CFG/GENI_SER_S_CLK_CFG */
102 #define SER_CLK_EN (BIT(0))
103 #define CLK_DIV_MSK (GENMASK(15, 4))
104 #define CLK_DIV_SHFT 4
106 /* SE_HW_PARAM_0 fields */
107 #define TX_FIFO_WIDTH_MSK (GENMASK(29, 24))
108 #define TX_FIFO_WIDTH_SHFT 24
109 #define TX_FIFO_DEPTH_MSK (GENMASK(21, 16))
110 #define TX_FIFO_DEPTH_SHFT 16
112 /* GENI SE QUP Registers */
113 #define QUP_HW_VER_REG 0x4
114 #define QUP_SE_VERSION_2_5 0x20050000
117 * Predefined packing configuration of the serial engine (CFG0, CFG1 regs)
120 * Defines following configuration:
121 * - Bits of data per transfer word 8
122 * - Number of words per fifo element 4
123 * - Transfer from MSB to LSB or vice-versa false
125 #define UART_PACKING_CFG0 0xf
126 #define UART_PACKING_CFG1 0x0
128 DECLARE_GLOBAL_DATA_PTR;
130 struct msm_serial_data {
136 unsigned long root_freq[] = {7372800, 14745600, 19200000, 29491200,
137 32000000, 48000000, 64000000, 80000000,
138 96000000, 100000000};
141 * get_clk_cfg() - Get clock rate to apply on clock supplier.
142 * @clk_freq: Desired clock frequency after build-in divider.
144 * Return: frequency, supported by clock supplier, multiple of clk_freq.
146 static int get_clk_cfg(unsigned long clk_freq)
148 for (int i = 0; i < ARRAY_SIZE(root_freq); i++) {
149 if (!(root_freq[i] % clk_freq))
156 * get_clk_div_rate() - Find clock supplier frequency, and calculate divisor.
158 * @sampling_rate: Clock ticks per character.
159 * @clk_div: Pointer to calculated divisor.
161 * This function searches for suitable frequency for clock supplier,
162 * calculates divisor for internal divider, based on found frequency,
163 * and stores divisor under clk_div pointer.
165 * Return: frequency, supported by clock supplier, multiple of clk_freq.
167 static int get_clk_div_rate(u32 baud, u64 sampling_rate, u32 *clk_div)
169 unsigned long ser_clk;
170 unsigned long desired_clk;
172 desired_clk = baud * sampling_rate;
173 ser_clk = get_clk_cfg(desired_clk);
175 pr_err("%s: Can't find matching DFS entry for baud %d\n",
180 *clk_div = ser_clk / desired_clk;
184 static int geni_serial_set_clock_rate(struct udevice *dev, u64 rate)
189 clk = devm_clk_get(dev, NULL);
193 ret = clk_set_rate(clk, rate);
198 * geni_se_get_tx_fifo_depth() - Get the TX fifo depth of the serial engine
199 * @base: Pointer to the concerned serial engine.
201 * This function is used to get the depth i.e. number of elements in the
202 * TX fifo of the serial engine.
204 * Return: TX fifo depth in units of FIFO words.
206 static inline u32 geni_se_get_tx_fifo_depth(long base)
210 tx_fifo_depth = ((readl(base + SE_HW_PARAM_0) & TX_FIFO_DEPTH_MSK) >>
212 return tx_fifo_depth;
216 * geni_se_get_tx_fifo_width() - Get the TX fifo width of the serial engine
217 * @base: Pointer to the concerned serial engine.
219 * This function is used to get the width i.e. word size per element in the
220 * TX fifo of the serial engine.
222 * Return: TX fifo width in bits
224 static inline u32 geni_se_get_tx_fifo_width(long base)
228 tx_fifo_width = ((readl(base + SE_HW_PARAM_0) & TX_FIFO_WIDTH_MSK) >>
230 return tx_fifo_width;
233 static inline void geni_serial_baud(phys_addr_t base_address, u32 clk_div,
238 s_clk_cfg |= SER_CLK_EN;
239 s_clk_cfg |= (clk_div << CLK_DIV_SHFT);
241 writel(s_clk_cfg, base_address + GENI_SER_M_CLK_CFG);
242 writel(s_clk_cfg, base_address + GENI_SER_S_CLK_CFG);
245 static int msm_serial_setbrg(struct udevice *dev, int baud)
247 struct msm_serial_data *priv = dev_get_priv(dev);
254 clk_rate = get_clk_div_rate(baud, priv->oversampling, &clk_div);
255 ret = geni_serial_set_clock_rate(dev, clk_rate);
257 pr_err("%s: Couldn't set clock rate: %d\n", __func__, ret);
260 geni_serial_baud(priv->base, clk_div, baud);
266 * qcom_geni_serial_poll_bit() - Poll reg bit until desired value or timeout.
267 * @base: Pointer to the concerned serial engine.
268 * @offset: Offset to register address.
269 * @field: AND bitmask for desired bit.
270 * @set: Desired bit value.
272 * This function is used to get the width i.e. word size per element in the
273 * TX fifo of the serial engine.
275 * Return: true, when register bit equals desired value, false, when timeout
278 static bool qcom_geni_serial_poll_bit(const struct udevice *dev, int offset,
282 struct msm_serial_data *priv = dev_get_priv(dev);
284 unsigned int tx_fifo_depth;
285 unsigned int tx_fifo_width;
286 unsigned int fifo_bits;
287 unsigned long timeout_us = 10000;
295 tx_fifo_depth = geni_se_get_tx_fifo_depth(priv->base);
296 tx_fifo_width = geni_se_get_tx_fifo_width(priv->base);
297 fifo_bits = tx_fifo_depth * tx_fifo_width;
299 * Total polling iterations based on FIFO worth of bytes to be
300 * sent at current baud. Add a little fluff to the wait.
302 timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
305 timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
307 reg = readl(priv->base + offset);
308 if ((bool)(reg & field) == set)
316 static void qcom_geni_serial_setup_tx(u64 base, u32 xmit_size)
320 writel(xmit_size, base + SE_UART_TX_TRANS_LEN);
321 m_cmd = UART_START_TX << M_OPCODE_SHIFT;
322 writel(m_cmd, base + SE_GENI_M_CMD0);
325 static inline void qcom_geni_serial_poll_tx_done(const struct udevice *dev)
327 struct msm_serial_data *priv = dev_get_priv(dev);
329 u32 irq_clear = M_CMD_DONE_EN;
331 done = qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
332 M_CMD_DONE_EN, true);
334 writel(M_GENI_CMD_ABORT, priv->base + SE_GENI_M_CMD_CTRL_REG);
335 irq_clear |= M_CMD_ABORT_EN;
336 qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
337 M_CMD_ABORT_EN, true);
339 writel(irq_clear, priv->base + SE_GENI_M_IRQ_CLEAR);
342 static u32 qcom_geni_serial_tx_empty(u64 base)
344 return !readl(base + SE_GENI_TX_FIFO_STATUS);
348 * geni_se_setup_s_cmd() - Setup the secondary sequencer
349 * @se: Pointer to the concerned serial engine.
350 * @cmd: Command/Operation to setup in the secondary sequencer.
351 * @params: Parameter for the sequencer command.
353 * This function is used to configure the secondary sequencer with the
354 * command and its associated parameters.
356 static inline void geni_se_setup_s_cmd(u64 base, u32 cmd, u32 params)
360 s_cmd = readl(base + SE_GENI_S_CMD0);
361 s_cmd &= ~(S_OPCODE_MSK | S_PARAMS_MSK);
362 s_cmd |= (cmd << S_OPCODE_SHIFT);
363 s_cmd |= (params & S_PARAMS_MSK);
364 writel(s_cmd, base + SE_GENI_S_CMD0);
367 static void qcom_geni_serial_start_tx(u64 base)
372 status = readl(base + SE_GENI_STATUS);
373 if (status & M_GENI_CMD_ACTIVE)
376 if (!qcom_geni_serial_tx_empty(base))
379 irq_en = readl(base + SE_GENI_M_IRQ_EN);
380 irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
382 writel(DEF_TX_WM, base + SE_GENI_TX_WATERMARK_REG);
383 writel(irq_en, base + SE_GENI_M_IRQ_EN);
386 static void qcom_geni_serial_start_rx(struct udevice *dev)
389 struct msm_serial_data *priv = dev_get_priv(dev);
391 status = readl(priv->base + SE_GENI_STATUS);
393 geni_se_setup_s_cmd(priv->base, UART_START_READ, 0);
395 setbits_le32(priv->base + SE_GENI_S_IRQ_EN, S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
396 setbits_le32(priv->base + SE_GENI_M_IRQ_EN, M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
399 static void qcom_geni_serial_abort_rx(struct udevice *dev)
401 struct msm_serial_data *priv = dev_get_priv(dev);
403 u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
405 writel(S_GENI_CMD_ABORT, priv->base + SE_GENI_S_CMD_CTRL_REG);
406 qcom_geni_serial_poll_bit(dev, SE_GENI_S_CMD_CTRL_REG,
407 S_GENI_CMD_ABORT, false);
408 writel(irq_clear, priv->base + SE_GENI_S_IRQ_CLEAR);
409 writel(FORCE_DEFAULT, priv->base + GENI_FORCE_DEFAULT_REG);
412 static void msm_geni_serial_setup_rx(struct udevice *dev)
414 struct msm_serial_data *priv = dev_get_priv(dev);
416 qcom_geni_serial_abort_rx(dev);
418 writel(UART_PACKING_CFG0, priv->base + SE_GENI_RX_PACKING_CFG0);
419 writel(UART_PACKING_CFG1, priv->base + SE_GENI_RX_PACKING_CFG1);
421 geni_se_setup_s_cmd(priv->base, UART_START_READ, 0);
423 setbits_le32(priv->base + SE_GENI_S_IRQ_EN, S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
424 setbits_le32(priv->base + SE_GENI_M_IRQ_EN, M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
427 static int msm_serial_putc(struct udevice *dev, const char ch)
429 struct msm_serial_data *priv = dev_get_priv(dev);
431 writel(DEF_TX_WM, priv->base + SE_GENI_TX_WATERMARK_REG);
432 qcom_geni_serial_setup_tx(priv->base, 1);
434 qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
435 M_TX_FIFO_WATERMARK_EN, true);
437 writel(ch, priv->base + SE_GENI_TX_FIFOn);
438 writel(M_TX_FIFO_WATERMARK_EN, priv->base + SE_GENI_M_IRQ_CLEAR);
440 qcom_geni_serial_poll_tx_done(dev);
445 static int msm_serial_getc(struct udevice *dev)
447 struct msm_serial_data *priv = dev_get_priv(dev);
452 writel(1 << S_OPCODE_SHIFT, priv->base + SE_GENI_S_CMD0);
454 qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS, M_SEC_IRQ_EN,
457 m_irq_status = readl(priv->base + SE_GENI_M_IRQ_STATUS);
458 s_irq_status = readl(priv->base + SE_GENI_S_IRQ_STATUS);
459 writel(m_irq_status, priv->base + SE_GENI_M_IRQ_CLEAR);
460 writel(s_irq_status, priv->base + SE_GENI_S_IRQ_CLEAR);
461 qcom_geni_serial_poll_bit(dev, SE_GENI_RX_FIFO_STATUS, RX_FIFO_WC_MSK,
464 if (!readl(priv->base + SE_GENI_RX_FIFO_STATUS))
467 rx_fifo = readl(priv->base + SE_GENI_RX_FIFOn);
468 return rx_fifo & 0xff;
471 static int msm_serial_pending(struct udevice *dev, bool input)
473 struct msm_serial_data *priv = dev_get_priv(dev);
476 return readl(priv->base + SE_GENI_RX_FIFO_STATUS) &
479 return readl(priv->base + SE_GENI_TX_FIFO_STATUS) &
485 static const struct dm_serial_ops msm_serial_ops = {
486 .putc = msm_serial_putc,
487 .pending = msm_serial_pending,
488 .getc = msm_serial_getc,
489 .setbrg = msm_serial_setbrg,
492 static int geni_set_oversampling(struct udevice *dev)
494 struct msm_serial_data *priv = dev_get_priv(dev);
495 ofnode parent_node = ofnode_get_parent(dev_ofnode(dev));
499 priv->oversampling = UART_OVERSAMPLING;
502 * It could happen that GENI SE IP is missing in the board's device
503 * tree or GENI UART node is a direct child of SoC device tree node.
505 if (!ofnode_device_is_compatible(parent_node, "qcom,geni-se-qup")) {
506 pr_err("%s: UART node must be a child of geniqup node\n",
511 /* Read the HW_VER register relative to the parents address space */
512 addr = ofnode_get_addr(parent_node);
513 geni_se_version = readl(addr + QUP_HW_VER_REG);
515 if (geni_se_version >= QUP_SE_VERSION_2_5)
516 priv->oversampling /= 2;
521 static inline void geni_serial_init(struct udevice *dev)
523 struct msm_serial_data *priv = dev_get_priv(dev);
524 phys_addr_t base_address = priv->base;
526 u32 tx_parity_cfg = 0; /* Disable Tx Parity */
527 u32 rx_trans_cfg = 0;
528 u32 rx_parity_cfg = 0; /* Disable Rx Parity */
529 u32 stop_bit_len = 0; /* Default stop bit length - 1 bit */
533 * Ignore Flow control.
536 tx_trans_cfg = UART_CTS_MASK;
537 bits_per_char = BITS_PER_BYTE;
540 * Make an unconditional cancel on the main sequencer to reset
541 * it else we could end up in data loss scenarios.
543 qcom_geni_serial_poll_tx_done(dev);
544 qcom_geni_serial_abort_rx(dev);
546 writel(UART_PACKING_CFG0, base_address + SE_GENI_TX_PACKING_CFG0);
547 writel(UART_PACKING_CFG1, base_address + SE_GENI_TX_PACKING_CFG1);
548 writel(UART_PACKING_CFG0, base_address + SE_GENI_RX_PACKING_CFG0);
549 writel(UART_PACKING_CFG1, base_address + SE_GENI_RX_PACKING_CFG1);
551 writel(tx_trans_cfg, base_address + SE_UART_TX_TRANS_CFG);
552 writel(tx_parity_cfg, base_address + SE_UART_TX_PARITY_CFG);
553 writel(rx_trans_cfg, base_address + SE_UART_RX_TRANS_CFG);
554 writel(rx_parity_cfg, base_address + SE_UART_RX_PARITY_CFG);
555 writel(bits_per_char, base_address + SE_UART_TX_WORD_LEN);
556 writel(bits_per_char, base_address + SE_UART_RX_WORD_LEN);
557 writel(stop_bit_len, base_address + SE_UART_TX_STOP_BIT_LEN);
560 static int msm_serial_probe(struct udevice *dev)
562 struct msm_serial_data *priv = dev_get_priv(dev);
565 ret = geni_set_oversampling(dev);
569 /* No need to reinitialize the UART after relocation */
570 if (gd->flags & GD_FLG_RELOC)
573 geni_serial_init(dev);
574 msm_geni_serial_setup_rx(dev);
575 qcom_geni_serial_start_rx(dev);
576 qcom_geni_serial_start_tx(priv->base);
581 static int msm_serial_ofdata_to_platdata(struct udevice *dev)
583 struct msm_serial_data *priv = dev_get_priv(dev);
585 priv->base = dev_read_addr(dev);
586 if (priv->base == FDT_ADDR_T_NONE)
592 static const struct udevice_id msm_serial_ids[] = {
593 { .compatible = "qcom,geni-debug-uart" },
597 U_BOOT_DRIVER(serial_msm_geni) = {
598 .name = "serial_msm_geni",
600 .of_match = msm_serial_ids,
601 .of_to_plat = msm_serial_ofdata_to_platdata,
602 .priv_auto = sizeof(struct msm_serial_data),
603 .probe = msm_serial_probe,
604 .ops = &msm_serial_ops,
605 .flags = DM_FLAG_PRE_RELOC | DM_FLAG_DEFAULT_PD_CTRL_OFF,
608 static const struct udevice_id geniqup_ids[] = {
609 { .compatible = "qcom,geni-se-qup" },
613 U_BOOT_DRIVER(geni_se_qup) = {
614 .name = "geni-se-qup",
616 .of_match = geniqup_ids,
617 .bind = dm_scan_fdt_dev,
618 .flags = DM_FLAG_PRE_RELOC | DM_FLAG_DEFAULT_PD_CTRL_OFF,
621 #ifdef CONFIG_DEBUG_UART_MSM_GENI
623 static struct msm_serial_data init_serial_data = {
624 .base = CONFIG_VAL(DEBUG_UART_BASE)
627 /* Serial dumb device, to reuse driver code */
628 static struct udevice init_dev = {
629 .priv_ = &init_serial_data,
632 #include <debug_uart.h>
634 #define CLK_DIV (CONFIG_DEBUG_UART_CLOCK / \
635 (CONFIG_BAUDRATE * UART_OVERSAMPLING))
636 #if (CONFIG_DEBUG_UART_CLOCK % (CONFIG_BAUDRATE * UART_OVERSAMPLING) > 0)
637 #error Clocks cannot be set at early debug. Change CONFIG_BAUDRATE
640 static inline void _debug_uart_init(void)
642 phys_addr_t base = CONFIG_VAL(DEBUG_UART_BASE);
644 geni_serial_init(&init_dev);
645 geni_serial_baud(base, CLK_DIV, CONFIG_BAUDRATE);
646 qcom_geni_serial_start_tx(base);
649 static inline void _debug_uart_putc(int ch)
651 phys_addr_t base = CONFIG_VAL(DEBUG_UART_BASE);
653 writel(DEF_TX_WM, base + SE_GENI_TX_WATERMARK_REG);
654 qcom_geni_serial_setup_tx(base, 1);
655 qcom_geni_serial_poll_bit(&init_dev, SE_GENI_M_IRQ_STATUS,
656 M_TX_FIFO_WATERMARK_EN, true);
658 writel(ch, base + SE_GENI_TX_FIFOn);
659 writel(M_TX_FIFO_WATERMARK_EN, base + SE_GENI_M_IRQ_CLEAR);
660 qcom_geni_serial_poll_tx_done(&init_dev);