Messages in this thread | | | Date | Fri, 21 Jul 2023 17:13:55 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH v3 07/42] soc: Add SoC driver for Cirrus ep93xx |
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On Thu, Jul 20, 2023 at 02:29:07PM +0300, Nikita Shubin via B4 Relay wrote: > From: Nikita Shubin <nikita.shubin@maquefel.me> > > This adds an SoC driver for the ep93xx. Currently there > is only one thing not fitting into any other framework, > and that is the swlock setting. > > It's used for clock settings and restart.
> +#include <linux/clk-provider.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/mfd/syscon.h> > +#include <linux/of.h> > +#include <linux/regmap.h> > +#include <linux/slab.h> > +#include <linux/sys_soc.h> > +#include <linux/soc/cirrus/ep93xx.h>
...
> +#define EP93XX_SYSCON_SYSCFG_REV_MASK 0xf0000000
GENMASK() (you will need bits.h, and looking below you seem missed it anyway)
...
> + spin_lock_irqsave(&ep93xx_swlock, flags); > + > + regmap_read(map, EP93XX_SYSCON_DEVCFG, &val); > + val &= ~clear_bits; > + val |= set_bits; > + regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK); > + regmap_write(map, EP93XX_SYSCON_DEVCFG, val);
Is this sequence a must? I.o.w. can you first supply magic and then update devcfg?
> + spin_unlock_irqrestore(&ep93xx_swlock, flags);
...
> +void ep93xx_swlocked_update_bits(struct regmap *map, unsigned int reg, > + unsigned int mask, unsigned int val) > +{
Same Q as above.
> +}
...
> + int rev = ep93xx_chip_revision(map); > + > + switch (rev) {
switch(ep93xx_chip_revision(map))
?
> + case EP93XX_CHIP_REV_D0: > + return "D0"; > + case EP93XX_CHIP_REV_D1: > + return "D1"; > + case EP93XX_CHIP_REV_E0: > + return "E0"; > + case EP93XX_CHIP_REV_E1: > + return "E1"; > + case EP93XX_CHIP_REV_E2: > + return "E2"; > + default: > + return "unknown"; > + }
...
> +static unsigned long __init calc_pll_rate(u64 rate, u32 config_word) > +{ > + rate *= ((config_word >> 11) & GENMASK(4, 0)) + 1; /* X1FBD */ > + rate *= ((config_word >> 5) & GENMASK(5, 0)) + 1; /* X2FBD */ > + do_div(rate, (config_word & GENMASK(4, 0)) + 1); /* X2IPD */ > + rate >>= ((config_word >> 16) & 3); /* PS */
GENMASK()
> + return rate; > +}
...
> + /* Multiplatform guard, only proceed on ep93xx */ > + if (!of_machine_is_compatible("cirrus,ep9301")) > + return 0;
Why?
> + map = syscon_regmap_lookup_by_compatible("cirrus,ep9301-syscon"); > + if (IS_ERR(map)) > + return PTR_ERR(map);
Is this not enough?
...
> + if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1)) > + clk_pll1_rate = EP93XX_EXT_CLK_RATE; > + else > + clk_pll1_rate = calc_pll_rate(EP93XX_EXT_CLK_RATE, value);
Positive conditionals in if-else are easier to be read.
...
> + clk_f_div = fclk_divisors[(value >> 25) & 0x7]; > + clk_h_div = hclk_divisors[(value >> 20) & 0x7]; > + clk_p_div = pclk_divisors[(value >> 18) & 0x3];
GENMASK() in all three?
...
> + np = of_find_node_by_path("/"); > + of_property_read_string(np, "model", &machine); > + if (machine) > + attrs->machine = kstrdup(machine, GFP_KERNEL);
No error check?
> + of_node_put(np);
Looks like NIH of_flat_dt_get_machine_name(). Can you rather make use of it as it's done, e.g., here arch/riscv/kernel/setup.c:251?
-- With Best Regards, Andy Shevchenko
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