forked from sdr/rtl-sdr
Merge pull request 'r82xx: improved tuning speed and accuracy' (#6) from sultanqasim/rtl-sdr:upstream_fast_retune into master
Reviewed-on: sdr/rtl-sdr#6
This commit is contained in:
commit
ef23f806ec
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@ -25,6 +25,7 @@
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#include <stdio.h>
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#include <stdint.h>
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#include <string.h>
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#include <stdbool.h>
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#include "rtlsdr_i2c.h"
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#include "tuner_r82xx.h"
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@ -243,6 +244,7 @@ static void shadow_store(struct r82xx_priv *priv, uint8_t reg, const uint8_t *va
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if (r < 0) {
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len += r;
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val -= r;
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r = 0;
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}
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if (len <= 0)
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@ -253,11 +255,29 @@ static void shadow_store(struct r82xx_priv *priv, uint8_t reg, const uint8_t *va
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memcpy(&priv->regs[r], val, len);
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}
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static bool shadow_equal(struct r82xx_priv *priv, uint8_t reg, const uint8_t *val,
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int len)
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{
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int r = reg - REG_SHADOW_START;
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if (r < 0 || len < 0 || len > NUM_REGS - r)
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return false;
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if (memcmp(&priv->regs[r], val, len) == 0)
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return true;
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return false;
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}
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static int r82xx_write(struct r82xx_priv *priv, uint8_t reg, const uint8_t *val,
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unsigned int len)
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{
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int rc, size, pos = 0;
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/* Avoid setting registers unnecessarily since it's slow */
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if (shadow_equal(priv, reg, val, len))
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return 0;
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/* Store the shadow registers */
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shadow_store(priv, reg, val, len);
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@ -424,17 +444,21 @@ static int r82xx_set_mux(struct r82xx_priv *priv, uint32_t freq)
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return rc;
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}
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static inline uint8_t mask_reg8(uint8_t reg, uint8_t val, uint8_t mask)
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{
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return (reg & ~mask) | (val & mask);
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}
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static int r82xx_set_pll(struct r82xx_priv *priv, uint32_t freq)
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{
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int rc, i;
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unsigned sleep_time = 10000;
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uint64_t vco_freq;
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uint32_t vco_fra; /* VCO contribution by SDM (kHz) */
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uint32_t vco_min = 1770000;
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uint32_t vco_max = vco_min * 2;
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uint32_t freq_khz, pll_ref, pll_ref_khz;
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uint16_t n_sdm = 2;
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uint16_t sdm = 0;
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uint64_t vco_div;
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uint32_t vco_min = 1770000; /* kHz */
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uint32_t vco_max = vco_min * 2; /* kHz */
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uint32_t freq_khz, pll_ref;
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uint32_t sdm = 0;
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uint8_t mix_div = 2;
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uint8_t div_buf = 0;
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uint8_t div_num = 0;
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@ -442,25 +466,24 @@ static int r82xx_set_pll(struct r82xx_priv *priv, uint32_t freq)
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uint8_t refdiv2 = 0;
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uint8_t ni, si, nint, vco_fine_tune, val;
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uint8_t data[5];
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uint8_t regs[7];
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/* Frequency in kHz */
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freq_khz = (freq + 500) / 1000;
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pll_ref = priv->cfg->xtal;
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pll_ref_khz = (priv->cfg->xtal + 500) / 1000;
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rc = r82xx_write_reg_mask(priv, 0x10, refdiv2, 0x10);
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if (rc < 0)
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return rc;
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/* set pll autotune = 128kHz */
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rc = r82xx_write_reg_mask(priv, 0x1a, 0x00, 0x0c);
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if (rc < 0)
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return rc;
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/* regs 0x10 to 0x16 */
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memcpy(regs, &priv->regs[0x10 - REG_SHADOW_START], 7);
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regs[0] = mask_reg8(regs[0], refdiv2, 0x10);
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/* set VCO current = 100 */
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rc = r82xx_write_reg_mask(priv, 0x12, 0x80, 0xe0);
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if (rc < 0)
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return rc;
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regs[2] = mask_reg8(regs[2], 0x80, 0xe0);
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/* Calculate divider */
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while (mix_div <= 64) {
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@ -490,13 +513,27 @@ static int r82xx_set_pll(struct r82xx_priv *priv, uint32_t freq)
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else if (vco_fine_tune < vco_power_ref)
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div_num = div_num + 1;
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rc = r82xx_write_reg_mask(priv, 0x10, div_num << 5, 0xe0);
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if (rc < 0)
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return rc;
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regs[0] = mask_reg8(regs[0], div_num << 5, 0xe0);
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vco_freq = (uint64_t)freq * (uint64_t)mix_div;
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nint = vco_freq / (2 * pll_ref);
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vco_fra = (vco_freq - 2 * pll_ref * nint) / 1000;
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/* We want to approximate:
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* vco_freq / (2 * pll_ref)
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*
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* in the form:
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* nint + sdm/65536
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*
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* where nint,sdm are integers and 0 < nint, 0 <= sdm < 65536
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*
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* Scaling to fixed point and rounding:
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*
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* vco_div = 65536*(nint + sdm/65536) = int( 0.5 + 65536 * vco_freq / (2 * pll_ref) )
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* vco_div = 65536*nint + sdm = int( (pll_ref + 65536 * vco_freq) / (2 * pll_ref) )
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*/
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vco_div = (pll_ref + 65536 * vco_freq) / (2 * pll_ref);
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nint = (uint32_t) (vco_div / 65536);
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sdm = (uint32_t) (vco_div % 65536);
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if (nint > ((128 / vco_power_ref) - 1)) {
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fprintf(stderr, "[R82XX] No valid PLL values for %u Hz!\n", freq);
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@ -506,35 +543,20 @@ static int r82xx_set_pll(struct r82xx_priv *priv, uint32_t freq)
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ni = (nint - 13) / 4;
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si = nint - 4 * ni - 13;
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rc = r82xx_write_reg(priv, 0x14, ni + (si << 6));
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if (rc < 0)
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return rc;
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regs[4] = ni + (si << 6);
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/* pw_sdm */
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if (!vco_fra)
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if (sdm == 0)
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val = 0x08;
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else
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val = 0x00;
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rc = r82xx_write_reg_mask(priv, 0x12, val, 0x08);
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if (rc < 0)
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return rc;
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regs[2] = mask_reg8(regs[2], val, 0x08);
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/* sdm calculator */
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while (vco_fra > 1) {
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if (vco_fra > (2 * pll_ref_khz / n_sdm)) {
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sdm = sdm + 32768 / (n_sdm / 2);
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vco_fra = vco_fra - 2 * pll_ref_khz / n_sdm;
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if (n_sdm >= 0x8000)
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break;
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}
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n_sdm <<= 1;
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}
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regs[5] = sdm & 0xff;
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regs[6] = sdm >> 8;
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rc = r82xx_write_reg(priv, 0x16, sdm >> 8);
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if (rc < 0)
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return rc;
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rc = r82xx_write_reg(priv, 0x15, sdm & 0xff);
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rc = r82xx_write(priv, 0x10, regs, 7);
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if (rc < 0)
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return rc;
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@ -1317,6 +1339,7 @@ int r82xx_init(struct r82xx_priv *priv)
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priv->xtal_cap_sel = XTAL_HIGH_CAP_0P;
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/* Initialize registers */
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memset(priv->regs, 0, NUM_REGS);
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rc = r82xx_write(priv, 0x05,
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r82xx_init_array, sizeof(r82xx_init_array));
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