diff options
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/aspeed/clk_ast2500.c | 265 |
1 files changed, 234 insertions, 31 deletions
diff --git a/drivers/clk/aspeed/clk_ast2500.c b/drivers/clk/aspeed/clk_ast2500.c index 9e4c66e..7b4b5c6 100644 --- a/drivers/clk/aspeed/clk_ast2500.c +++ b/drivers/clk/aspeed/clk_ast2500.c @@ -12,16 +12,39 @@ #include <dm/lists.h> #include <dt-bindings/clock/ast2500-scu.h> +/* + * MAC Clock Delay settings, taken from Aspeed SDK + */ +#define RGMII_TXCLK_ODLY 8 +#define RMII_RXCLK_IDLY 2 + +/* + * TGMII Clock Duty constants, taken from Aspeed SDK + */ +#define RGMII2_TXCK_DUTY 0x66 +#define RGMII1_TXCK_DUTY 0x64 + +#define D2PLL_DEFAULT_RATE (250 * 1000 * 1000) + DECLARE_GLOBAL_DATA_PTR; /* + * Clock divider/multiplier configuration struct. * For H-PLL and M-PLL the formula is * (Output Frequency) = CLKIN * ((M + 1) / (N + 1)) / (P + 1) * M - Numerator * N - Denumerator * P - Post Divider * They have the same layout in their control register. + * + * D-PLL and D2-PLL have extra divider (OD + 1), which is not + * yet needed and ignored by clock configurations. */ +struct ast2500_div_config { + unsigned int num; + unsigned int denum; + unsigned int post_div; +}; /* * Get the rate of the M-PLL clock from input clock frequency and @@ -143,30 +166,41 @@ static ulong ast2500_clk_get_rate(struct clk *clk) return rate; } -static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate) +/* + * @input_rate - the rate of input clock in Hz + * @requested_rate - desired output rate in Hz + * @div - this is an IN/OUT parameter, at input all fields of the config + * need to be set to their maximum allowed values. + * The result (the best config we could find), would also be returned + * in this structure. + * + * @return The clock rate, when the resulting div_config is used. + */ +static ulong ast2500_calc_clock_config(ulong input_rate, ulong requested_rate, + struct ast2500_div_config *cfg) { - ulong clkin = ast2500_get_clkin(scu); - u32 mpll_reg; - /* - * There are not that many combinations of numerator, denumerator - * and post divider, so just brute force the best combination. - * However, to avoid overflow when multiplying, use kHz. + * The assumption is that kHz precision is good enough and + * also enough to avoid overflow when multiplying. */ - const ulong clkin_khz = clkin / 1000; - const ulong rate_khz = rate / 1000; - ulong best_num = 0; - ulong best_denum = 0; - ulong best_post = 0; - ulong delta = rate; - ulong num, denum, post; - - for (denum = 0; denum <= SCU_MPLL_DENUM_MASK; ++denum) { - for (post = 0; post <= SCU_MPLL_POST_MASK; ++post) { - num = (rate_khz * (post + 1) / clkin_khz) * (denum + 1); - ulong new_rate_khz = (clkin_khz - * ((num + 1) / (denum + 1))) - / (post + 1); + const ulong input_rate_khz = input_rate / 1000; + const ulong rate_khz = requested_rate / 1000; + const struct ast2500_div_config max_vals = *cfg; + struct ast2500_div_config it = { 0, 0, 0 }; + ulong delta = rate_khz; + ulong new_rate_khz = 0; + + for (; it.denum <= max_vals.denum; ++it.denum) { + for (it.post_div = 0; it.post_div <= max_vals.post_div; + ++it.post_div) { + it.num = (rate_khz * (it.post_div + 1) / input_rate_khz) + * (it.denum + 1); + if (it.num > max_vals.num) + continue; + + new_rate_khz = (input_rate_khz + * ((it.num + 1) / (it.denum + 1))) + / (it.post_div + 1); /* Keep the rate below requested one. */ if (new_rate_khz > rate_khz) @@ -174,25 +208,35 @@ static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate) if (new_rate_khz - rate_khz < delta) { delta = new_rate_khz - rate_khz; - - best_num = num; - best_denum = denum; - best_post = post; - + *cfg = it; if (delta == 0) - goto rate_calc_done; + return new_rate_khz * 1000; } } } - rate_calc_done: + return new_rate_khz * 1000; +} + +static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate) +{ + ulong clkin = ast2500_get_clkin(scu); + u32 mpll_reg; + struct ast2500_div_config div_cfg = { + .num = SCU_MPLL_NUM_MASK, + .denum = SCU_MPLL_DENUM_MASK, + .post_div = SCU_MPLL_POST_MASK + }; + + ast2500_calc_clock_config(clkin, rate, &div_cfg); + mpll_reg = readl(&scu->m_pll_param); mpll_reg &= ~((SCU_MPLL_POST_MASK << SCU_MPLL_POST_SHIFT) | (SCU_MPLL_NUM_MASK << SCU_MPLL_NUM_SHIFT) | (SCU_MPLL_DENUM_MASK << SCU_MPLL_DENUM_SHIFT)); - mpll_reg |= (best_post << SCU_MPLL_POST_SHIFT) - | (best_num << SCU_MPLL_NUM_SHIFT) - | (best_denum << SCU_MPLL_DENUM_SHIFT); + mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT) + | (div_cfg.num << SCU_MPLL_NUM_SHIFT) + | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT); ast_scu_unlock(scu); writel(mpll_reg, &scu->m_pll_param); @@ -201,6 +245,136 @@ static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate) return ast2500_get_mpll_rate(clkin, mpll_reg); } +static ulong ast2500_configure_mac(struct ast2500_scu *scu, int index) +{ + ulong clkin = ast2500_get_clkin(scu); + ulong hpll_rate = ast2500_get_hpll_rate(clkin, + readl(&scu->h_pll_param)); + ulong required_rate; + u32 hwstrap; + u32 divisor; + u32 reset_bit; + u32 clkstop_bit; + + /* + * According to data sheet, for 10/100 mode the MAC clock frequency + * should be at least 25MHz and for 1000 mode at least 100MHz + */ + hwstrap = readl(&scu->hwstrap); + if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII)) + required_rate = 100 * 1000 * 1000; + else + required_rate = 25 * 1000 * 1000; + + divisor = hpll_rate / required_rate; + + if (divisor < 4) { + /* Clock can't run fast enough, but let's try anyway */ + debug("MAC clock too slow\n"); + divisor = 4; + } else if (divisor > 16) { + /* Can't slow down the clock enough, but let's try anyway */ + debug("MAC clock too fast\n"); + divisor = 16; + } + + switch (index) { + case 1: + reset_bit = SCU_SYSRESET_MAC1; + clkstop_bit = SCU_CLKSTOP_MAC1; + break; + case 2: + reset_bit = SCU_SYSRESET_MAC2; + clkstop_bit = SCU_CLKSTOP_MAC2; + break; + default: + return -EINVAL; + } + + ast_scu_unlock(scu); + clrsetbits_le32(&scu->clk_sel1, SCU_MACCLK_MASK, + ((divisor - 2) / 2) << SCU_MACCLK_SHIFT); + + /* + * Disable MAC, start its clock and re-enable it. + * The procedure and the delays (100us & 10ms) are + * specified in the datasheet. + */ + setbits_le32(&scu->sysreset_ctrl1, reset_bit); + udelay(100); + clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit); + mdelay(10); + clrbits_le32(&scu->sysreset_ctrl1, reset_bit); + + writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT) + | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT), + &scu->clk_duty_sel); + + ast_scu_lock(scu); + + return required_rate; +} + +static ulong ast2500_configure_d2pll(struct ast2500_scu *scu, ulong rate) +{ + /* + * The values and the meaning of the next three + * parameters are undocumented. Taken from Aspeed SDK. + */ + const u32 d2_pll_ext_param = 0x2c; + const u32 d2_pll_sip = 0x11; + const u32 d2_pll_sic = 0x18; + u32 clk_delay_settings = + (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT) + | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT) + | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT) + | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT); + struct ast2500_div_config div_cfg = { + .num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT, + .denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT, + .post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT, + }; + ulong clkin = ast2500_get_clkin(scu); + ulong new_rate; + + ast_scu_unlock(scu); + writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT) + | SCU_D2PLL_EXT1_OFF + | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]); + + /* + * Select USB2.0 port1 PHY clock as a clock source for GCRT. + * This would disconnect it from D2-PLL. + */ + clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF, + SCU_MISC_GCRT_USB20CLK); + + new_rate = ast2500_calc_clock_config(clkin, rate, &div_cfg); + writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT) + | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT) + | (div_cfg.num << SCU_D2PLL_NUM_SHIFT) + | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT) + | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT), + &scu->d2_pll_param); + + clrbits_le32(&scu->d2_pll_ext_param[0], + SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET); + + clrsetbits_le32(&scu->misc_ctrl2, + SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL + | SCU_MISC2_RGMII_CLKDIV_MASK | + SCU_MISC2_RMII_CLKDIV_MASK, + (4 << SCU_MISC2_RMII_CLKDIV_SHIFT)); + + writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay); + writel(clk_delay_settings, &scu->mac_clk_delay_100M); + writel(clk_delay_settings, &scu->mac_clk_delay_10M); + + ast_scu_lock(scu); + + return new_rate; +} + static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate) { struct ast2500_clk_priv *priv = dev_get_priv(clk->dev); @@ -211,6 +385,9 @@ static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate) case MCLK_DDR: new_rate = ast2500_configure_ddr(priv->scu, rate); break; + case PLL_D2PLL: + new_rate = ast2500_configure_d2pll(priv->scu, rate); + break; default: return -ENOENT; } @@ -218,9 +395,35 @@ static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate) return new_rate; } +static int ast2500_clk_enable(struct clk *clk) +{ + struct ast2500_clk_priv *priv = dev_get_priv(clk->dev); + + switch (clk->id) { + /* + * For MAC clocks the clock rate is + * configured based on whether RGMII or RMII mode has been selected + * through hardware strapping. + */ + case PCLK_MAC1: + ast2500_configure_mac(priv->scu, 1); + break; + case PCLK_MAC2: + ast2500_configure_mac(priv->scu, 2); + break; + case PLL_D2PLL: + ast2500_configure_d2pll(priv->scu, D2PLL_DEFAULT_RATE); + default: + return -ENOENT; + } + + return 0; +} + struct clk_ops ast2500_clk_ops = { .get_rate = ast2500_clk_get_rate, .set_rate = ast2500_clk_set_rate, + .enable = ast2500_clk_enable, }; static int ast2500_clk_probe(struct udevice *dev) |