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Diffstat (limited to 'drivers/clk/clk-si5341.c')
| -rw-r--r-- | drivers/clk/clk-si5341.c | 1346 |
1 files changed, 1346 insertions, 0 deletions
diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c new file mode 100644 index 000000000000..72424eb7e5f8 --- /dev/null +++ b/drivers/clk/clk-si5341.c @@ -0,0 +1,1346 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for Silicon Labs Si5341/Si5340 Clock generator + * Copyright (C) 2019 Topic Embedded Products + * Author: Mike Looijmans <mike.looijmans@topic.nl> + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/gcd.h> +#include <linux/math64.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <asm/unaligned.h> + +#define SI5341_MAX_NUM_OUTPUTS 10 +#define SI5340_MAX_NUM_OUTPUTS 4 + +#define SI5341_NUM_SYNTH 5 +#define SI5340_NUM_SYNTH 4 + +/* Range of the synthesizer fractional divider */ +#define SI5341_SYNTH_N_MIN 10 +#define SI5341_SYNTH_N_MAX 4095 + +/* The chip can get its input clock from 3 input pins or an XTAL */ + +/* There is one PLL running at 13500–14256 MHz */ +#define SI5341_PLL_VCO_MIN 13500000000ull +#define SI5341_PLL_VCO_MAX 14256000000ull + +/* The 5 frequency synthesizers obtain their input from the PLL */ +struct clk_si5341_synth { + struct clk_hw hw; + struct clk_si5341 *data; + u8 index; +}; +#define to_clk_si5341_synth(_hw) \ + container_of(_hw, struct clk_si5341_synth, hw) + +/* The output stages can be connected to any synth (full mux) */ +struct clk_si5341_output { + struct clk_hw hw; + struct clk_si5341 *data; + u8 index; +}; +#define to_clk_si5341_output(_hw) \ + container_of(_hw, struct clk_si5341_output, hw) + +struct clk_si5341 { + struct clk_hw hw; + struct regmap *regmap; + struct i2c_client *i2c_client; + struct clk_si5341_synth synth[SI5341_NUM_SYNTH]; + struct clk_si5341_output clk[SI5341_MAX_NUM_OUTPUTS]; + struct clk *pxtal; + const char *pxtal_name; + const u16 *reg_output_offset; + const u16 *reg_rdiv_offset; + u64 freq_vco; /* 13500–14256 MHz */ + u8 num_outputs; + u8 num_synth; +}; +#define to_clk_si5341(_hw) container_of(_hw, struct clk_si5341, hw) + +struct clk_si5341_output_config { + u8 out_format_drv_bits; + u8 out_cm_ampl_bits; + bool synth_master; + bool always_on; +}; + +#define SI5341_PAGE 0x0001 +#define SI5341_PN_BASE 0x0002 +#define SI5341_DEVICE_REV 0x0005 +#define SI5341_STATUS 0x000C +#define SI5341_SOFT_RST 0x001C + +/* Input dividers (48-bit) */ +#define SI5341_IN_PDIV(x) (0x0208 + ((x) * 10)) +#define SI5341_IN_PSET(x) (0x020E + ((x) * 10)) + +/* PLL configuration */ +#define SI5341_PLL_M_NUM 0x0235 +#define SI5341_PLL_M_DEN 0x023B + +/* Output configuration */ +#define SI5341_OUT_CONFIG(output) \ + ((output)->data->reg_output_offset[(output)->index]) +#define SI5341_OUT_FORMAT(output) (SI5341_OUT_CONFIG(output) + 1) +#define SI5341_OUT_CM(output) (SI5341_OUT_CONFIG(output) + 2) +#define SI5341_OUT_MUX_SEL(output) (SI5341_OUT_CONFIG(output) + 3) +#define SI5341_OUT_R_REG(output) \ + ((output)->data->reg_rdiv_offset[(output)->index]) + +/* Synthesize N divider */ +#define SI5341_SYNTH_N_NUM(x) (0x0302 + ((x) * 11)) +#define SI5341_SYNTH_N_DEN(x) (0x0308 + ((x) * 11)) +#define SI5341_SYNTH_N_UPD(x) (0x030C + ((x) * 11)) + +/* Synthesizer output enable, phase bypass, power mode */ +#define SI5341_SYNTH_N_CLK_TO_OUTX_EN 0x0A03 +#define SI5341_SYNTH_N_PIBYP 0x0A04 +#define SI5341_SYNTH_N_PDNB 0x0A05 +#define SI5341_SYNTH_N_CLK_DIS 0x0B4A + +#define SI5341_REGISTER_MAX 0xBFF + +/* SI5341_OUT_CONFIG bits */ +#define SI5341_OUT_CFG_PDN BIT(0) +#define SI5341_OUT_CFG_OE BIT(1) +#define SI5341_OUT_CFG_RDIV_FORCE2 BIT(2) + +/* Static configuration (to be moved to firmware) */ +struct si5341_reg_default { + u16 address; + u8 value; +}; + +/* Output configuration registers 0..9 are not quite logically organized */ +static const u16 si5341_reg_output_offset[] = { + 0x0108, + 0x010D, + 0x0112, + 0x0117, + 0x011C, + 0x0121, + 0x0126, + 0x012B, + 0x0130, + 0x013A, +}; + +static const u16 si5340_reg_output_offset[] = { + 0x0112, + 0x0117, + 0x0126, + 0x012B, +}; + +/* The location of the R divider registers */ +static const u16 si5341_reg_rdiv_offset[] = { + 0x024A, + 0x024D, + 0x0250, + 0x0253, + 0x0256, + 0x0259, + 0x025C, + 0x025F, + 0x0262, + 0x0268, +}; +static const u16 si5340_reg_rdiv_offset[] = { + 0x0250, + 0x0253, + 0x025C, + 0x025F, +}; + +/* + * Programming sequence from ClockBuilder, settings to initialize the system + * using only the XTAL input, without pre-divider. + * This also contains settings that aren't mentioned anywhere in the datasheet. + * The "known" settings like synth and output configuration are done later. + */ +static const struct si5341_reg_default si5341_reg_defaults[] = { + { 0x0017, 0x3A }, /* INT mask (disable interrupts) */ + { 0x0018, 0xFF }, /* INT mask */ + { 0x0021, 0x0F }, /* Select XTAL as input */ + { 0x0022, 0x00 }, /* Not in datasheet */ + { 0x002B, 0x02 }, /* SPI config */ + { 0x002C, 0x20 }, /* LOS enable for XTAL */ + { 0x002D, 0x00 }, /* LOS timing */ + { 0x002E, 0x00 }, + { 0x002F, 0x00 }, + { 0x0030, 0x00 }, + { 0x0031, 0x00 }, + { 0x0032, 0x00 }, + { 0x0033, 0x00 }, + { 0x0034, 0x00 }, + { 0x0035, 0x00 }, + { 0x0036, 0x00 }, + { 0x0037, 0x00 }, + { 0x0038, 0x00 }, /* LOS setting (thresholds) */ + { 0x0039, 0x00 }, + { 0x003A, 0x00 }, + { 0x003B, 0x00 }, + { 0x003C, 0x00 }, + { 0x003D, 0x00 }, /* LOS setting (thresholds) end */ + { 0x0041, 0x00 }, /* LOS0_DIV_SEL */ + { 0x0042, 0x00 }, /* LOS1_DIV_SEL */ + { 0x0043, 0x00 }, /* LOS2_DIV_SEL */ + { 0x0044, 0x00 }, /* LOS3_DIV_SEL */ + { 0x009E, 0x00 }, /* Not in datasheet */ + { 0x0102, 0x01 }, /* Enable outputs */ + { 0x013F, 0x00 }, /* Not in datasheet */ + { 0x0140, 0x00 }, /* Not in datasheet */ + { 0x0141, 0x40 }, /* OUT LOS */ + { 0x0202, 0x00 }, /* XAXB_FREQ_OFFSET (=0)*/ + { 0x0203, 0x00 }, + { 0x0204, 0x00 }, + { 0x0205, 0x00 }, + { 0x0206, 0x00 }, /* PXAXB (2^x) */ + { 0x0208, 0x00 }, /* Px divider setting (usually 0) */ + { 0x0209, 0x00 }, + { 0x020A, 0x00 }, + { 0x020B, 0x00 }, + { 0x020C, 0x00 }, + { 0x020D, 0x00 }, + { 0x020E, 0x00 }, + { 0x020F, 0x00 }, + { 0x0210, 0x00 }, + { 0x0211, 0x00 }, + { 0x0212, 0x00 }, + { 0x0213, 0x00 }, + { 0x0214, 0x00 }, + { 0x0215, 0x00 }, + { 0x0216, 0x00 }, + { 0x0217, 0x00 }, + { 0x0218, 0x00 }, + { 0x0219, 0x00 }, + { 0x021A, 0x00 }, + { 0x021B, 0x00 }, + { 0x021C, 0x00 }, + { 0x021D, 0x00 }, + { 0x021E, 0x00 }, + { 0x021F, 0x00 }, + { 0x0220, 0x00 }, + { 0x0221, 0x00 }, + { 0x0222, 0x00 }, + { 0x0223, 0x00 }, + { 0x0224, 0x00 }, + { 0x0225, 0x00 }, + { 0x0226, 0x00 }, + { 0x0227, 0x00 }, + { 0x0228, 0x00 }, + { 0x0229, 0x00 }, + { 0x022A, 0x00 }, + { 0x022B, 0x00 }, + { 0x022C, 0x00 }, + { 0x022D, 0x00 }, + { 0x022E, 0x00 }, + { 0x022F, 0x00 }, /* Px divider setting (usually 0) end */ + { 0x026B, 0x00 }, /* DESIGN_ID (ASCII string) */ + { 0x026C, 0x00 }, + { 0x026D, 0x00 }, + { 0x026E, 0x00 }, + { 0x026F, 0x00 }, + { 0x0270, 0x00 }, + { 0x0271, 0x00 }, + { 0x0272, 0x00 }, /* DESIGN_ID (ASCII string) end */ + { 0x0339, 0x1F }, /* N_FSTEP_MSK */ + { 0x033B, 0x00 }, /* Nx_FSTEPW (Frequency step) */ + { 0x033C, 0x00 }, + { 0x033D, 0x00 }, + { 0x033E, 0x00 }, + { 0x033F, 0x00 }, + { 0x0340, 0x00 }, + { 0x0341, 0x00 }, + { 0x0342, 0x00 }, + { 0x0343, 0x00 }, + { 0x0344, 0x00 }, + { 0x0345, 0x00 }, + { 0x0346, 0x00 }, + { 0x0347, 0x00 }, + { 0x0348, 0x00 }, + { 0x0349, 0x00 }, + { 0x034A, 0x00 }, + { 0x034B, 0x00 }, + { 0x034C, 0x00 }, + { 0x034D, 0x00 }, + { 0x034E, 0x00 }, + { 0x034F, 0x00 }, + { 0x0350, 0x00 }, + { 0x0351, 0x00 }, + { 0x0352, 0x00 }, + { 0x0353, 0x00 }, + { 0x0354, 0x00 }, + { 0x0355, 0x00 }, + { 0x0356, 0x00 }, + { 0x0357, 0x00 }, + { 0x0358, 0x00 }, /* Nx_FSTEPW (Frequency step) end */ + { 0x0359, 0x00 }, /* Nx_DELAY */ + { 0x035A, 0x00 }, + { 0x035B, 0x00 }, + { 0x035C, 0x00 }, + { 0x035D, 0x00 }, + { 0x035E, 0x00 }, + { 0x035F, 0x00 }, + { 0x0360, 0x00 }, + { 0x0361, 0x00 }, + { 0x0362, 0x00 }, /* Nx_DELAY end */ + { 0x0802, 0x00 }, /* Not in datasheet */ + { 0x0803, 0x00 }, /* Not in datasheet */ + { 0x0804, 0x00 }, /* Not in datasheet */ + { 0x090E, 0x02 }, /* XAXB_EXTCLK_EN=0 XAXB_PDNB=1 (use XTAL) */ + { 0x091C, 0x04 }, /* ZDM_EN=4 (Normal mode) */ + { 0x0943, 0x00 }, /* IO_VDD_SEL=0 (0=1v8, use 1=3v3) */ + { 0x0949, 0x00 }, /* IN_EN (disable input clocks) */ + { 0x094A, 0x00 }, /* INx_TO_PFD_EN (disabled) */ + { 0x0A02, 0x00 }, /* Not in datasheet */ + { 0x0B44, 0x0F }, /* PDIV_ENB (datasheet does not mention what it is) */ +}; + +/* Read and interpret a 44-bit followed by a 32-bit value in the regmap */ +static int si5341_decode_44_32(struct regmap *regmap, unsigned int reg, + u64 *val1, u32 *val2) +{ + int err; + u8 r[10]; + + err = regmap_bulk_read(regmap, reg, r, 10); + if (err < 0) + return err; + + *val1 = ((u64)((r[5] & 0x0f) << 8 | r[4]) << 32) | + (get_unaligned_le32(r)); + *val2 = get_unaligned_le32(&r[6]); + + return 0; +} + +static int si5341_encode_44_32(struct regmap *regmap, unsigned int reg, + u64 n_num, u32 n_den) +{ + u8 r[10]; + + /* Shift left as far as possible without overflowing */ + while (!(n_num & BIT_ULL(43)) && !(n_den & BIT(31))) { + n_num <<= 1; + n_den <<= 1; + } + + /* 44 bits (6 bytes) numerator */ + put_unaligned_le32(n_num, r); + r[4] = (n_num >> 32) & 0xff; + r[5] = (n_num >> 40) & 0x0f; + /* 32 bits denominator */ + put_unaligned_le32(n_den, &r[6]); + + /* Program the fraction */ + return regmap_bulk_write(regmap, reg, r, sizeof(r)); +} + +/* VCO, we assume it runs at a constant frequency */ +static unsigned long si5341_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_si5341 *data = to_clk_si5341(hw); + int err; + u64 res; + u64 m_num; + u32 m_den; + unsigned int shift; + + /* Assume that PDIV is not being used, just read the PLL setting */ + err = si5341_decode_44_32(data->regmap, SI5341_PLL_M_NUM, + &m_num, &m_den); + if (err < 0) + return 0; + + if (!m_num || !m_den) + return 0; + + /* + * Though m_num is 64-bit, only the upper bits are actually used. While + * calculating m_num and m_den, they are shifted as far as possible to + * the left. To avoid 96-bit division here, we just shift them back so + * we can do with just 64 bits. + */ + shift = 0; + res = m_num; + while (res & 0xffff00000000ULL) { + ++shift; + res >>= 1; + } + res *= parent_rate; + do_div(res, (m_den >> shift)); + + /* We cannot return the actual frequency in 32 bit, store it locally */ + data->freq_vco = res; + + /* Report kHz since the value is out of range */ + do_div(res, 1000); + + return (unsigned long)res; +} + +static const struct clk_ops si5341_clk_ops = { + .recalc_rate = si5341_clk_recalc_rate, +}; + +/* Synthesizers, there are 5 synthesizers that connect to any of the outputs */ + +/* The synthesizer is on if all power and enable bits are set */ +static int si5341_synth_clk_is_on(struct clk_hw *hw) +{ + struct clk_si5341_synth *synth = to_clk_si5341_synth(hw); + int err; + u32 val; + u8 index = synth->index; + + err = regmap_read(synth->data->regmap, + SI5341_SYNTH_N_CLK_TO_OUTX_EN, &val); + if (err < 0) + return 0; + + if (!(val & BIT(index))) + return 0; + + err = regmap_read(synth->data->regmap, SI5341_SYNTH_N_PDNB, &val); + if (err < 0) + return 0; + + if (!(val & BIT(index))) + return 0; + + /* This bit must be 0 for the synthesizer to receive clock input */ + err = regmap_read(synth->data->regmap, SI5341_SYNTH_N_CLK_DIS, &val); + if (err < 0) + return 0; + + return !(val & BIT(index)); +} + +static void si5341_synth_clk_unprepare(struct clk_hw *hw) +{ + struct clk_si5341_synth *synth = to_clk_si5341_synth(hw); + u8 index = synth->index; /* In range 0..5 */ + u8 mask = BIT(index); + + /* Disable output */ + regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_CLK_TO_OUTX_EN, mask, 0); + /* Power down */ + regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_PDNB, mask, 0); + /* Disable clock input to synth (set to 1 to disable) */ + regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_CLK_DIS, mask, mask); +} + +static int si5341_synth_clk_prepare(struct clk_hw *hw) +{ + struct clk_si5341_synth *synth = to_clk_si5341_synth(hw); + int err; + u8 index = synth->index; + u8 mask = BIT(index); + + /* Power up */ + err = regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_PDNB, mask, mask); + if (err < 0) + return err; + + /* Enable clock input to synth (set bit to 0 to enable) */ + err = regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_CLK_DIS, mask, 0); + if (err < 0) + return err; + + /* Enable output */ + return regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_CLK_TO_OUTX_EN, mask, mask); +} + +/* Synth clock frequency: Fvco * n_den / n_den, with Fvco in 13500-14256 MHz */ +static unsigned long si5341_synth_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_si5341_synth *synth = to_clk_si5341_synth(hw); + u64 f; + u64 n_num; + u32 n_den; + int err; + + err = si5341_decode_44_32(synth->data->regmap, + SI5341_SYNTH_N_NUM(synth->index), &n_num, &n_den); + if (err < 0) + return err; + + /* + * n_num and n_den are shifted left as much as possible, so to prevent + * overflow in 64-bit math, we shift n_den 4 bits to the right + */ + f = synth->data->freq_vco; + f *= n_den >> 4; + + /* Now we need to to 64-bit division: f/n_num */ + /* And compensate for the 4 bits we dropped */ + f = div64_u64(f, (n_num >> 4)); + + return f; +} + +static long si5341_synth_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_si5341_synth *synth = to_clk_si5341_synth(hw); + u64 f; + + /* The synthesizer accuracy is such that anything in range will work */ + f = synth->data->freq_vco; + do_div(f, SI5341_SYNTH_N_MAX); + if (rate < f) + return f; + + f = synth->data->freq_vco; + do_div(f, SI5341_SYNTH_N_MIN); + if (rate > f) + return f; + + return rate; +} + +static int si5341_synth_program(struct clk_si5341_synth *synth, + u64 n_num, u32 n_den, bool is_integer) +{ + int err; + u8 index = synth->index; + + err = si5341_encode_44_32(synth->data->regmap, + SI5341_SYNTH_N_NUM(index), n_num, n_den); + + err = regmap_update_bits(synth->data->regmap, + SI5341_SYNTH_N_PIBYP, BIT(index), is_integer ? BIT(index) : 0); + if (err < 0) + return err; + + return regmap_write(synth->data->regmap, + SI5341_SYNTH_N_UPD(index), 0x01); +} + + +static int si5341_synth_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_si5341_synth *synth = to_clk_si5341_synth(hw); + u64 n_num; + u32 n_den; + u32 r; + u32 g; + bool is_integer; + + n_num = synth->data->freq_vco; + n_den = rate; + + /* see if there's an integer solution */ + r = do_div(n_num, rate); + is_integer = (r == 0); + if (is_integer) { + /* Integer divider equal to n_num */ + n_den = 1; + } else { + /* Calculate a fractional solution */ + g = gcd(r, rate); + n_den = rate / g; + n_num *= n_den; + n_num += r / g; + } + + dev_dbg(&synth->data->i2c_client->dev, + "%s(%u): n=0x%llx d=0x%x %s\n", __func__, + synth->index, n_num, n_den, + is_integer ? "int" : "frac"); + + return si5341_synth_program(synth, n_num, n_den, is_integer); +} + +static const struct clk_ops si5341_synth_clk_ops = { + .is_prepared = si5341_synth_clk_is_on, + .prepare = si5341_synth_clk_prepare, + .unprepare = si5341_synth_clk_unprepare, + .recalc_rate = si5341_synth_clk_recalc_rate, + .round_rate = si5341_synth_clk_round_rate, + .set_rate = si5341_synth_clk_set_rate, +}; + +static int si5341_output_clk_is_on(struct clk_hw *hw) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + int err; + u32 val; + + err = regmap_read(output->data->regmap, + SI5341_OUT_CONFIG(output), &val); + if (err < 0) + return err; + + /* Bit 0=PDN, 1=OE so only a value of 0x2 enables the output */ + return (val & 0x03) == SI5341_OUT_CFG_OE; +} + +/* Disables and then powers down the output */ +static void si5341_output_clk_unprepare(struct clk_hw *hw) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + + regmap_update_bits(output->data->regmap, + SI5341_OUT_CONFIG(output), + SI5341_OUT_CFG_OE, 0); + regmap_update_bits(output->data->regmap, + SI5341_OUT_CONFIG(output), + SI5341_OUT_CFG_PDN, SI5341_OUT_CFG_PDN); +} + +/* Powers up and then enables the output */ +static int si5341_output_clk_prepare(struct clk_hw *hw) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + int err; + + err = regmap_update_bits(output->data->regmap, + SI5341_OUT_CONFIG(output), + SI5341_OUT_CFG_PDN, 0); + if (err < 0) + return err; + + return regmap_update_bits(output->data->regmap, + SI5341_OUT_CONFIG(output), + SI5341_OUT_CFG_OE, SI5341_OUT_CFG_OE); +} + +static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + int err; + u32 val; + u32 r_divider; + u8 r[3]; + + err = regmap_bulk_read(output->data->regmap, + SI5341_OUT_R_REG(output), r, 3); + if (err < 0) + return err; + + /* Calculate value as 24-bit integer*/ + r_divider = r[2] << 16 | r[1] << 8 | r[0]; + + /* If Rx_REG is zero, the divider is disabled, so return a "0" rate */ + if (!r_divider) + return 0; + + /* Divider is 2*(Rx_REG+1) */ + r_divider += 1; + r_divider <<= 1; + + err = regmap_read(output->data->regmap, + SI5341_OUT_CONFIG(output), &val); + if (err < 0) + return err; + + if (val & SI5341_OUT_CFG_RDIV_FORCE2) + r_divider = 2; + + return parent_rate / r_divider; +} + +static long si5341_output_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned long r; + + r = *parent_rate >> 1; + + /* If rate is an even divisor, no changes to parent required */ + if (r && !(r % rate)) + return (long)rate; + + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { + if (rate > 200000000) { + /* minimum r-divider is 2 */ + r = 2; + } else { + /* Take a parent frequency near 400 MHz */ + r = (400000000u / rate) & ~1; + } + *parent_rate = r * rate; + } else { + /* We cannot change our parent's rate, report what we can do */ + r /= rate; + rate = *parent_rate / (r << 1); + } + + return rate; +} + +static int si5341_output_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + /* Frequency divider is (r_div + 1) * 2 */ + u32 r_div = (parent_rate / rate) >> 1; + int err; + u8 r[3]; + + if (r_div <= 1) + r_div = 0; + else if (r_div >= BIT(24)) + r_div = BIT(24) - 1; + else + --r_div; + + /* For a value of "2", we set the "OUT0_RDIV_FORCE2" bit */ + err = regmap_update_bits(output->data->regmap, + SI5341_OUT_CONFIG(output), + SI5341_OUT_CFG_RDIV_FORCE2, + (r_div == 0) ? SI5341_OUT_CFG_RDIV_FORCE2 : 0); + if (err < 0) + return err; + + /* Always write Rx_REG, because a zero value disables the divider */ + r[0] = r_div ? (r_div & 0xff) : 1; + r[1] = (r_div >> 8) & 0xff; + r[2] = (r_div >> 16) & 0xff; + err = regmap_bulk_write(output->data->regmap, + SI5341_OUT_R_REG(output), r, 3); + + return 0; +} + +static int si5341_output_reparent(struct clk_si5341_output *output, u8 index) +{ + return regmap_update_bits(output->data->regmap, + SI5341_OUT_MUX_SEL(output), 0x07, index); +} + +static int si5341_output_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + + if (index >= output->data->num_synth) + return -EINVAL; + + return si5341_output_reparent(output, index); +} + +static u8 si5341_output_get_parent(struct clk_hw *hw) +{ + struct clk_si5341_output *output = to_clk_si5341_output(hw); + int err; + u32 val; + + err = regmap_read(output->data->regmap, + SI5341_OUT_MUX_SEL(output), &val); + + return val & 0x7; +} + +static const struct clk_ops si5341_output_clk_ops = { + .is_prepared = si5341_output_clk_is_on, + .prepare = si5341_output_clk_prepare, + .unprepare = si5341_output_clk_unprepare, + .recalc_rate = si5341_output_clk_recalc_rate, + .round_rate = si5341_output_clk_round_rate, + .set_rate = si5341_output_clk_set_rate, + .set_parent = si5341_output_set_parent, + .get_parent = si5341_output_get_parent, +}; + +/* + * The chip can be bought in a pre-programmed version, or one can program the + * NVM in the chip to boot up in a preset mode. This routine tries to determine + * if that's the case, or if we need to reset and program everything from + * scratch. Returns negative error, or true/false. + */ +static int si5341_is_programmed_already(struct clk_si5341 *data) +{ + int err; + u8 r[4]; + + /* Read the PLL divider value, it must have a non-zero value */ + err = regmap_bulk_read(data->regmap, SI5341_PLL_M_DEN, + r, ARRAY_SIZE(r)); + if (err < 0) + return err; + + return !!get_unaligned_le32(r); +} + +static struct clk_hw * +of_clk_si5341_get(struct of_phandle_args *clkspec, void *_data) +{ + struct clk_si5341 *data = _data; + unsigned int idx = clkspec->args[1]; + unsigned int group = clkspec->args[0]; + + switch (group) { + case 0: + if (idx >= data->num_outputs) { + dev_err(&data->i2c_client->dev, + "invalid output index %u\n", idx); + return ERR_PTR(-EINVAL); + } + return &data->clk[idx].hw; + case 1: + if (idx >= data->num_synth) { + dev_err(&data->i2c_client->dev, + "invalid synthesizer index %u\n", idx); + return ERR_PTR(-EINVAL); + } + return &data->synth[idx].hw; + case 2: + if (idx > 0) { + dev_err(&data->i2c_client->dev, + "invalid PLL index %u\n", idx); + return ERR_PTR(-EINVAL); + } + return &data->hw; + default: + dev_err(&data->i2c_client->dev, "invalid group %u\n", group); + return ERR_PTR(-EINVAL); + } +} + +static int si5341_probe_chip_id(struct clk_si5341 *data) +{ + int err; + u8 reg[4]; + u16 model; + + err = regmap_bulk_read(data->regmap, SI5341_PN_BASE, reg, + ARRAY_SIZE(reg)); + if (err < 0) { + dev_err(&data->i2c_client->dev, "Failed to read chip ID\n"); + return err; + } + + model = get_unaligned_le16(reg); + + dev_info(&data->i2c_client->dev, "Chip: %x Grade: %u Rev: %u\n", + model, reg[2], reg[3]); + + switch (model) { + case 0x5340: + data->num_outputs = SI5340_MAX_NUM_OUTPUTS; + data->num_synth = SI5340_NUM_SYNTH; + data->reg_output_offset = si5340_reg_output_offset; + data->reg_rdiv_offset = si5340_reg_rdiv_offset; + break; + case 0x5341: + data->num_outputs = SI5341_MAX_NUM_OUTPUTS; + data->num_synth = SI5341_NUM_SYNTH; + data->reg_output_offset = si5341_reg_output_offset; + data->reg_rdiv_offset = si5341_reg_rdiv_offset; + break; + default: + dev_err(&data->i2c_client->dev, "Model '%x' not supported\n", + model); + return -EINVAL; + } + + return 0; +} + +/* Read active settings into the regmap cache for later reference */ +static int si5341_read_settings(struct clk_si5341 *data) +{ + int err; + u8 i; + u8 r[10]; + + err = regmap_bulk_read(data->regmap, SI5341_PLL_M_NUM, r, 10); + if (err < 0) + return err; + + err = regmap_bulk_read(data->regmap, + SI5341_SYNTH_N_CLK_TO_OUTX_EN, r, 3); + if (err < 0) + return err; + + err = regmap_bulk_read(data->regmap, + SI5341_SYNTH_N_CLK_DIS, r, 1); + if (err < 0) + return err; + + for (i = 0; i < data->num_synth; ++i) { + err = regmap_bulk_read(data->regmap, + SI5341_SYNTH_N_NUM(i), r, 10); + if (err < 0) + return err; + } + + for (i = 0; i < data->num_outputs; ++i) { + err = regmap_bulk_read(data->regmap, + data->reg_output_offset[i], r, 4); + if (err < 0) + return err; + + err = regmap_bulk_read(data->regmap, + data->reg_rdiv_offset[i], r, 3); + if (err < 0) + return err; + } + + return 0; +} + +static int si5341_write_multiple(struct clk_si5341 *data, + const struct si5341_reg_default *values, unsigned int num_values) +{ + unsigned int i; + int res; + + for (i = 0; i < num_values; ++i) { + res = regmap_write(data->regmap, + values[i].address, values[i].value); + if (res < 0) { + dev_err(&data->i2c_client->dev, + "Failed to write %#x:%#x\n", + values[i].address, values[i].value); + return res; + } + } + + return 0; +} + +static const struct si5341_reg_default si5341_preamble[] = { + { 0x0B25, 0x00 }, + { 0x0502, 0x01 }, + { 0x0505, 0x03 }, + { 0x0957, 0x1F }, + { 0x0B4E, 0x1A }, +}; + +static int si5341_send_preamble(struct clk_si5341 *data) +{ + int res; + u32 revision; + + /* For revision 2 and up, the values are slightly different */ + res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision); + if (res < 0) + return res; + + /* Write "preamble" as specified by datasheet */ + res = regmap_write(data->regmap, 0xB24, revision < 2 ? 0xD8 : 0xC0); + if (res < 0) + return res; + res = si5341_write_multiple(data, + si5341_preamble, ARRAY_SIZE(si5341_preamble)); + if (res < 0) + return res; + + /* Datasheet specifies a 300ms wait after sending the preamble */ + msleep(300); + + return 0; +} + +/* Perform a soft reset and write post-amble */ +static int si5341_finalize_defaults(struct clk_si5341 *data) +{ + int res; + u32 revision; + + res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision); + if (res < 0) + return res; + + dev_dbg(&data->i2c_client->dev, "%s rev=%u\n", __func__, revision); + + res = regmap_write(data->regmap, SI5341_SOFT_RST, 0x01); + if (res < 0) + return res; + + /* Datasheet does not explain these nameless registers */ + res = regmap_write(data->regmap, 0xB24, revision < 2 ? 0xDB : 0xC3); + if (res < 0) + return res; + res = regmap_write(data->regmap, 0x0B25, 0x02); + if (res < 0) + return res; + + return 0; +} + + +static const struct regmap_range si5341_regmap_volatile_range[] = { + regmap_reg_range(0x000C, 0x0012), /* Status */ + regmap_reg_range(0x001C, 0x001E), /* reset, finc/fdec */ + regmap_reg_range(0x00E2, 0x00FE), /* NVM, interrupts, device ready */ + /* Update bits for synth config */ + regmap_reg_range(SI5341_SYNTH_N_UPD(0), SI5341_SYNTH_N_UPD(0)), + regmap_reg_range(SI5341_SYNTH_N_UPD(1), SI5341_SYNTH_N_UPD(1)), + regmap_reg_range(SI5341_SYNTH_N_UPD(2), SI5341_SYNTH_N_UPD(2)), + regmap_reg_range(SI5341_SYNTH_N_UPD(3), SI5341_SYNTH_N_UPD(3)), + regmap_reg_range(SI5341_SYNTH_N_UPD(4), SI5341_SYNTH_N_UPD(4)), +}; + +static const struct regmap_access_table si5341_regmap_volatile = { + .yes_ranges = si5341_regmap_volatile_range, + .n_yes_ranges = ARRAY_SIZE(si5341_regmap_volatile_range), +}; + +/* Pages 0, 1, 2, 3, 9, A, B are valid, so there are 12 pages */ +static const struct regmap_range_cfg si5341_regmap_ranges[] = { + { + .range_min = 0, + .range_max = SI5341_REGISTER_MAX, + .selector_reg = SI5341_PAGE, + .selector_mask = 0xff, + .selector_shift = 0, + .window_start = 0, + .window_len = 256, + }, +}; + +static const struct regmap_config si5341_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .cache_type = REGCACHE_RBTREE, + .ranges = si5341_regmap_ranges, + .num_ranges = ARRAY_SIZE(si5341_regmap_ranges), + .max_register = SI5341_REGISTER_MAX, + .volatile_table = &si5341_regmap_volatile, +}; + +static int si5341_dt_parse_dt(struct i2c_client *client, + struct clk_si5341_output_config *config) +{ + struct device_node *child; + struct device_node *np = client->dev.of_node; + u32 num; + u32 val; + + memset(config, 0, sizeof(struct clk_si5341_output_config) * + SI5341_MAX_NUM_OUTPUTS); + + for_each_child_of_node(np, child) { + if (of_property_read_u32(child, "reg", &num)) { + dev_err(&client->dev, "missing reg property of %s\n", + child->name); + goto put_child; + } + + if (num >= SI5341_MAX_NUM_OUTPUTS) { + dev_err(&client->dev, "invalid clkout %d\n", num); + goto put_child; + } + + if (!of_property_read_u32(child, "silabs,format", &val)) { + /* Set cm and ampl conservatively to 3v3 settings */ + switch (val) { + case 1: /* normal differential */ + config[num].out_cm_ampl_bits = 0x33; + break; + case 2: /* low-power differential */ + config[num].out_cm_ampl_bits = 0x13; + break; + case 4: /* LVCMOS */ + config[num].out_cm_ampl_bits = 0x33; + /* Set SI recommended impedance for LVCMOS */ + config[num].out_format_drv_bits |= 0xc0; + break; + default: + dev_err(&client->dev, + "invalid silabs,format %u for %u\n", + val, num); + goto put_child; + } + config[num].out_format_drv_bits &= ~0x07; + config[num].out_format_drv_bits |= val & 0x07; + /* Always enable the SYNC feature */ + config[num].out_format_drv_bits |= 0x08; + } + + if (!of_property_read_u32(child, "silabs,common-mode", &val)) { + if (val > 0xf) { + dev_err(&client->dev, + "invalid silabs,common-mode %u\n", + val); + goto put_child; + } + config[num].out_cm_ampl_bits &= 0xf0; + config[num].out_cm_ampl_bits |= val & 0x0f; + } + + if (!of_property_read_u32(child, "silabs,amplitude", &val)) { + if (val > 0xf) { + dev_err(&client->dev, + "invalid silabs,amplitude %u\n", + val); + goto put_child; + } + config[num].out_cm_ampl_bits &= 0x0f; + config[num].out_cm_ampl_bits |= (val << 4) & 0xf0; + } + + if (of_property_read_bool(child, "silabs,disable-high")) + config[num].out_format_drv_bits |= 0x10; + + config[num].synth_master = + of_property_read_bool(child, "silabs,synth-master"); + + config[num].always_on = + of_property_read_bool(child, "always-on"); + } + + return 0; + +put_child: + of_node_put(child); + return -EINVAL; +} + +/* + * If not pre-configured, calculate and set the PLL configuration manually. + * For low-jitter performance, the PLL should be set such that the synthesizers + * only need integer division. + * Without any user guidance, we'll set the PLL to 14GHz, which still allows + * the chip to generate any frequency on its outputs, but jitter performance + * may be sub-optimal. + */ +static int si5341_initialize_pll(struct clk_si5341 *data) +{ + struct device_node *np = data->i2c_client->dev.of_node; + u32 m_num = 0; + u32 m_den = 0; + + if (of_property_read_u32(np, "silabs,pll-m-num", &m_num)) { + dev_err(&data->i2c_client->dev, + "PLL configuration requires silabs,pll-m-num\n"); + } + if (of_property_read_u32(np, "silabs,pll-m-den", &m_den)) { + dev_err(&data->i2c_client->dev, + "PLL configuration requires silabs,pll-m-den\n"); + } + + if (!m_num || !m_den) { + dev_err(&data->i2c_client->dev, + "PLL configuration invalid, assume 14GHz\n"); + m_den = clk_get_rate(data->pxtal) / 10; + m_num = 1400000000; + } + + return si5341_encode_44_32(data->regmap, + SI5341_PLL_M_NUM, m_num, m_den); +} + +static int si5341_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct clk_si5341 *data; + struct clk_init_data init; + const char *root_clock_name; + const char *synth_clock_names[SI5341_NUM_SYNTH]; + int err; + unsigned int i; + struct clk_si5341_output_config config[SI5341_MAX_NUM_OUTPUTS]; + bool initialization_required; + + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->i2c_client = client; + + data->pxtal = devm_clk_get(&client->dev, "xtal"); + if (IS_ERR(data->pxtal)) { + if (PTR_ERR(data->pxtal) == -EPROBE_DEFER) + return -EPROBE_DEFER; + + dev_err(&client->dev, "Missing xtal clock input\n"); + } + + err = si5341_dt_parse_dt(client, config); + if (err) + return err; + + if (of_property_read_string(client->dev.of_node, "clock-output-names", + &init.name)) + init.name = client->dev.of_node->name; + root_clock_name = init.name; + + data->regmap = devm_regmap_init_i2c(client, &si5341_regmap_config); + if (IS_ERR(data->regmap)) + return PTR_ERR(data->regmap); + + i2c_set_clientdata(client, data); + + err = si5341_probe_chip_id(data); + if (err < 0) + return err; + + /* "Activate" the xtal (usually a fixed clock) */ + clk_prepare_enable(data->pxtal); + + if (of_property_read_bool(client->dev.of_node, "silabs,reprogram")) { + initialization_required = true; + } else { + err = si5341_is_programmed_already(data); + if (err < 0) + return err; + + initialization_required = !err; + } + + if (initialization_required) { + /* Populate the regmap cache in preparation for "cache only" */ + err = si5341_read_settings(data); + if (err < 0) + return err; + + err = si5341_send_preamble(data); + if (err < 0) + return err; + + /* + * We intend to send all 'final' register values in a single + * transaction. So cache all register writes until we're done + * configuring. + */ + regcache_cache_only(data->regmap, true); + + /* Write the configuration pairs from the firmware blob */ + err = si5341_write_multiple(data, si5341_reg_defaults, + ARRAY_SIZE(si5341_reg_defaults)); + if (err < 0) + return err; + + /* PLL configuration is required */ + err = si5341_initialize_pll(data); + if (err < 0) + return err; + } + + /* Register the PLL */ + data->pxtal_name = __clk_get_name(data->pxtal); + init.parent_names = &data->pxtal_name; + init.num_parents = 1; /* For now, only XTAL input supported */ + init.ops = &si5341_clk_ops; + init.flags = 0; + data->hw.init = &init; + + err = devm_clk_hw_register(&client->dev, &data->hw); + if (err) { + dev_err(&client->dev, "clock registration failed\n"); + return err; + } + + init.num_parents = 1; + init.parent_names = &root_clock_name; + init.ops = &si5341_synth_clk_ops; + for (i = 0; i < data->num_synth; ++i) { + synth_clock_names[i] = devm_kasprintf(&client->dev, GFP_KERNEL, + "%s.N%u", client->dev.of_node->name, i); + init.name = synth_clock_names[i]; + data->synth[i].index = i; + data->synth[i].data = data; + data->synth[i].hw.init = &init; + err = devm_clk_hw_register(&client->dev, &data->synth[i].hw); + if (err) { + dev_err(&client->dev, + "synth N%u registration failed\n", i); + } + } + + init.num_parents = data->num_synth; + init.parent_names = synth_clock_names; + init.ops = &si5341_output_clk_ops; + for (i = 0; i < data->num_outputs; ++i) { + init.name = kasprintf(GFP_KERNEL, "%s.%d", + client->dev.of_node->name, i); + init.flags = config[i].synth_master ? CLK_SET_RATE_PARENT : 0; + data->clk[i].index = i; + data->clk[i].data = data; + data->clk[i].hw.init = &init; + if (config[i].out_format_drv_bits & 0x07) { + regmap_write(data->regmap, + SI5341_OUT_FORMAT(&data->clk[i]), + config[i].out_format_drv_bits); + regmap_write(data->regmap, + SI5341_OUT_CM(&data->clk[i]), + config[i].out_cm_ampl_bits); + } + err = devm_clk_hw_register(&client->dev, &data->clk[i].hw); + kfree(init.name); /* clock framework made a copy of the name */ + if (err) { + dev_err(&client->dev, + "output %u registration failed\n", i); + return err; + } + if (config[i].always_on) + clk_prepare(data->clk[i].hw.clk); + } + + err = of_clk_add_hw_provider(client->dev.of_node, of_clk_si5341_get, + data); + if (err) { + dev_err(&client->dev, "unable to add clk provider\n"); + return err; + } + + if (initialization_required) { + /* Synchronize */ + regcache_cache_only(data->regmap, false); + err = regcache_sync(data->regmap); + if (err < 0) + return err; + + err = si5341_finalize_defaults(data); + if (err < 0) + return err; + } + + /* Free the names, clk framework makes copies */ + for (i = 0; i < data->num_synth; ++i) + devm_kfree(&client->dev, (void *)synth_clock_names[i]); + + return 0; +} + +static const struct i2c_device_id si5341_id[] = { + { "si5340", 0 }, + { "si5341", 1 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, si5341_id); + +static const struct of_device_id clk_si5341_of_match[] = { + { .compatible = "silabs,si5340" }, + { .compatible = "silabs,si5341" }, + { } +}; +MODULE_DEVICE_TABLE(of, clk_si5341_of_match); + +static struct i2c_driver si5341_driver = { + .driver = { + .name = "si5341", + .of_match_table = clk_si5341_of_match, + }, + .probe = si5341_probe, + .id_table = si5341_id, +}; +module_i2c_driver(si5341_driver); + +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>"); +MODULE_DESCRIPTION("Si5341 driver"); +MODULE_LICENSE("GPL"); |