From 56b0ef13653c8f33d8ed4f6a98e5d599789fb954 Mon Sep 17 00:00:00 2001 From: Benjamin Chan Date: Mon, 30 May 2016 14:58:12 -0400 Subject: clk: msm: mdss: add SSC support for dsi PLL on msmcobalt Add support to control Spread Spectrum Clocking (SSC) in the DSI PLL on msmcobalt. CRs-Fixed: 1036187 Change-Id: I158670185976801970d54bec4bc42014b1b28b96 Signed-off-by: Benjamin Chan --- drivers/clk/msm/mdss/mdss-dsi-pll-cobalt.c | 119 +++++++++++++++++++++++++++-- 1 file changed, 114 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/clk/msm/mdss/mdss-dsi-pll-cobalt.c b/drivers/clk/msm/mdss/mdss-dsi-pll-cobalt.c index 1751f49b798c..19e813fd5a54 100644 --- a/drivers/clk/msm/mdss/mdss-dsi-pll-cobalt.c +++ b/drivers/clk/msm/mdss/mdss-dsi-pll-cobalt.c @@ -53,6 +53,13 @@ #define PLL_FRAC_DIV_START_LOW_1 0x0d0 #define PLL_FRAC_DIV_START_MID_1 0x0d4 #define PLL_FRAC_DIV_START_HIGH_1 0x0d8 +#define PLL_SSC_STEPSIZE_LOW_1 0x10c +#define PLL_SSC_STEPSIZE_HIGH_1 0x110 +#define PLL_SSC_DIV_PER_LOW_1 0x114 +#define PLL_SSC_DIV_PER_HIGH_1 0x118 +#define PLL_SSC_DIV_ADJPER_LOW_1 0x11c +#define PLL_SSC_DIV_ADJPER_HIGH_1 0x120 +#define PLL_SSC_CONTROL 0x13c #define PLL_PLL_OUTDIV_RATE 0x140 #define PLL_PLL_LOCKDET_RATE_1 0x144 #define PLL_PLL_PROP_GAIN_RATE_1 0x14c @@ -70,6 +77,16 @@ #define PHY_CMN_PLL_CNTRL 0x038 #define PHY_CMN_CTRL_0 0x024 +/* Bit definition of SSC control registers */ +#define SSC_CENTER BIT(0) +#define SSC_EN BIT(1) +#define SSC_FREQ_UPDATE BIT(2) +#define SSC_FREQ_UPDATE_MUX BIT(3) +#define SSC_UPDATE_SSC BIT(4) +#define SSC_UPDATE_SSC_MUX BIT(5) +#define SSC_START BIT(6) +#define SSC_START_MUX BIT(7) + enum { DSI_PLL_0, DSI_PLL_1, @@ -84,6 +101,13 @@ struct dsi_pll_regs { u32 frac_div_start_low; u32 frac_div_start_mid; u32 frac_div_start_high; + u32 ssc_stepsize_low; + u32 ssc_stepsize_high; + u32 ssc_div_per_low; + u32 ssc_div_per_high; + u32 ssc_adjper_low; + u32 ssc_adjper_high; + u32 ssc_control; }; struct dsi_pll_config { @@ -92,6 +116,8 @@ struct dsi_pll_config { u32 output_div; bool ignore_frac; bool disable_prescaler; + bool enable_ssc; + bool ssc_center; u32 dec_bits; u32 frac_bits; u32 lock_timer; @@ -151,7 +177,7 @@ static void dsi_pll_setup_config(struct dsi_pll_cobalt *pll, config->frac_bits = 18; config->lock_timer = 64; config->ssc_freq = 31500; - config->ssc_offset = 4800; + config->ssc_offset = 5000; config->ssc_adj_per = 2; config->thresh_cycles = 32; config->refclk_cycles = 256; @@ -159,6 +185,15 @@ static void dsi_pll_setup_config(struct dsi_pll_cobalt *pll, config->div_override = false; config->ignore_frac = false; config->disable_prescaler = false; + config->enable_ssc = rsc->ssc_en; + config->ssc_center = rsc->ssc_center; + + if (config->enable_ssc) { + if (rsc->ssc_freq) + config->ssc_freq = rsc->ssc_freq; + if (rsc->ssc_ppm) + config->ssc_offset = rsc->ssc_ppm; + } dsi_pll_config_slave(rsc); } @@ -227,6 +262,77 @@ static void dsi_pll_calc_dec_frac(struct dsi_pll_cobalt *pll, regs->frac_div_start_high = (frac & 0x30000) >> 16; } +static void dsi_pll_calc_ssc(struct dsi_pll_cobalt *pll, + struct mdss_pll_resources *rsc) +{ + struct dsi_pll_config *config = &pll->pll_configuration; + struct dsi_pll_regs *regs = &pll->reg_setup; + u32 ssc_per; + u32 ssc_mod; + u64 ssc_step_size; + u64 frac; + + if (!config->enable_ssc) { + pr_debug("SSC not enabled\n"); + return; + } + + ssc_per = DIV_ROUND_CLOSEST(config->ref_freq, config->ssc_freq) / 2 - 1; + ssc_mod = (ssc_per + 1) % (config->ssc_adj_per + 1); + ssc_per -= ssc_mod; + + frac = regs->frac_div_start_low | + (regs->frac_div_start_mid << 8) | + (regs->frac_div_start_high << 16); + ssc_step_size = regs->decimal_div_start; + ssc_step_size *= (1 << config->frac_bits); + ssc_step_size += frac; + ssc_step_size *= config->ssc_offset; + ssc_step_size *= (config->ssc_adj_per + 1); + ssc_step_size = div_u64(ssc_step_size, (ssc_per + 1)); + ssc_step_size = DIV_ROUND_CLOSEST_ULL(ssc_step_size, 1000000); + + regs->ssc_div_per_low = ssc_per & 0xFF; + regs->ssc_div_per_high = (ssc_per & 0xFF00) >> 8; + regs->ssc_stepsize_low = (u32)(ssc_step_size & 0xFF); + regs->ssc_stepsize_high = (u32)((ssc_step_size & 0xFF00) >> 8); + regs->ssc_adjper_low = config->ssc_adj_per & 0xFF; + regs->ssc_adjper_high = (config->ssc_adj_per & 0xFF00) >> 8; + + regs->ssc_control = config->ssc_center ? SSC_CENTER : 0; + + pr_debug("SCC: Dec:%d, frac:%llu, frac_bits:%d\n", + regs->decimal_div_start, frac, config->frac_bits); + pr_debug("SSC: div_per:0x%X, stepsize:0x%X, adjper:0x%X\n", + ssc_per, (u32)ssc_step_size, config->ssc_adj_per); +} + +static void dsi_pll_ssc_commit(struct dsi_pll_cobalt *pll, + struct mdss_pll_resources *rsc) +{ + void __iomem *pll_base = rsc->pll_base; + struct dsi_pll_regs *regs = &pll->reg_setup; + + if (pll->pll_configuration.enable_ssc) { + pr_debug("SSC is enabled\n"); + + MDSS_PLL_REG_W(pll_base, PLL_SSC_STEPSIZE_LOW_1, + regs->ssc_stepsize_low); + MDSS_PLL_REG_W(pll_base, PLL_SSC_STEPSIZE_HIGH_1, + regs->ssc_stepsize_high); + MDSS_PLL_REG_W(pll_base, PLL_SSC_DIV_PER_LOW_1, + regs->ssc_div_per_low); + MDSS_PLL_REG_W(pll_base, PLL_SSC_DIV_PER_HIGH_1, + regs->ssc_div_per_high); + MDSS_PLL_REG_W(pll_base, PLL_SSC_DIV_ADJPER_LOW_1, + regs->ssc_adjper_low); + MDSS_PLL_REG_W(pll_base, PLL_SSC_DIV_ADJPER_HIGH_1, + regs->ssc_adjper_high); + MDSS_PLL_REG_W(pll_base, PLL_SSC_CONTROL, + SSC_EN | regs->ssc_control); + } +} + static void dsi_pll_config_hzindep_reg(struct dsi_pll_cobalt *pll, struct mdss_pll_resources *rsc) { @@ -270,8 +376,6 @@ static void dsi_pll_commit(struct dsi_pll_cobalt *pll, MDSS_PLL_REG_W(pll_base, PLL_PLL_OUTDIV_RATE, reg->pll_outdiv_rate); MDSS_PLL_REG_W(pll_base, PLL_PLL_LOCK_DELAY, 0x0a); - /* flush, ensure all register writes are done*/ - wmb(); } static int vco_cobalt_set_rate(struct clk *c, unsigned long rate) @@ -311,11 +415,16 @@ static int vco_cobalt_set_rate(struct clk *c, unsigned long rate) dsi_pll_calc_dec_frac(pll, rsc); + dsi_pll_calc_ssc(pll, rsc); + + dsi_pll_commit(pll, rsc); + dsi_pll_config_hzindep_reg(pll, rsc); - /* todo: ssc configuration */ + dsi_pll_ssc_commit(pll, rsc); - dsi_pll_commit(pll, rsc); + /* flush, ensure all register writes are done*/ + wmb(); mdss_pll_resource_enable(rsc, false); -- cgit v1.2.3